SEC Form N-CSR filed by Pioneer Municipal High Income Opportunities Fund Inc.

 

 

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

 

 

FORM N-CSR

 

 

CERTIFIED SHAREHOLDER REPORT OF REGISTERED

MANAGEMENT INVESTMENT COMPANIES

Investment Company Act file number 811‑23699

 

 

Pioneer Municipal High Income Opportunities Fund, Inc.

(Exact name of registrant as specified in charter)

 

 

60 State Street, Boston, MA 02109

(Address of principal executive offices) (ZIP code)

 

 

Christopher J. Kelley, Amundi Asset Management, Inc.,

60 State Street, Boston, MA 02109

(Name and address of agent for service)

 

 

Registrant’s telephone number, including area code: (617) 742‑7825

Date of fiscal year end: April 30, 2024

Date of reporting period: May 1, 2023 through April 30, 2024

 

 

Form N‑CSR is to be used by management investment companies to file reports with the Commission not later than 10 days after the transmission to stockholders of any report that is required to be transmitted to stockholders under Rule 30e‑1 under the Investment Company Act of 1940 (17 CFR 270.30e‑1). The Commission may use the information provided on Form N‑CSR in its regulatory, disclosure review, inspection, and policymaking roles.

A registrant is required to disclose the information specified by Form N‑CSR, and the Commission will make this information public. A registrant is not required to respond to the collection of information contained in Form N‑CSR unless the Form displays a currently valid Office of Management and Budget (“OMB”) control number. Please direct comments concerning the accuracy of the information collection burden estimate and any suggestions for reducing the burden to Secretary, Securities and Exchange Commission, 450 Fifth Street, NW, Washington, DC 20549-0609. The OMB has reviewed this collection of information under the clearance requirements of 44 U.S.C. ss. 3507.

 

 

 

---

ITEM 1. REPORT TO STOCKHOLDERS.

 

---

Pioneer Municipal High Income Opportunities Fund, Inc.

Annual Report  |  April 30, 2024 

Ticker Symbol: MIO

---

---

visit us: www.amundi.com/us

---

---

Table of Contents

---

Portfolio Management Discussion	2
Portfolio Summary	9
Prices and Distributions	11
Performance Update	12
Schedule of Investments	14
Financial Statements	21
Notes to Financial Statements	27
Report of Independent Registered Public Accounting Firm	40
Additional Information (unaudited)	42
Investment Objectives, Principal Investment Strategies and Principal Risks	45
Effects of Leverage	82
Directors, Officers and Service Providers	84

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/241

---

---

Table of Contents

Portfolio Management Discussion  |  4/30/24

In the following interview, John (Jake) Crosby van Roden III* and Prakash Vadlamani* discuss the factors that affected the performance of Pioneer Municipal High Income Opportunities Fund, Inc. during the 12-month period ended April 30, 2024. Mr. van Roden, Managing Director and Director of Municipals and a portfolio manager at Amundi Asset Management US, Inc. (“Amundi US”), and Mr. Vadlamani, Senior Vice President, Senior Credit Analyst and associate portfolio manager at Amundi US, are responsible for the day-to-day management of the Fund.

Q	How did the Fund perform during the 12-month period ended April 30, 2024?
A	Pioneer Municipal High Income Opportunities Fund, Inc. returned 5.58% at net asset value (NAV) and 8.22% at market price during the 12-month period ended April 30, 2024. During the same 12-month period, the Fund’s benchmarks, the Bloomberg US Municipal High Yield Bond Index and the Bloomberg Municipal Bond Index, returned 6.63% and 2.08% at NAV, respectively. The Bloomberg US Municipal High Yield Bond Index is an unmanaged measure of the performance of lower rated municipal bonds, while the Bloomberg Municipal Bond Index is an unmanaged measure of the performance of investment-grade municipal bonds. Unlike the Fund, the two indices do not use leverage. While the use of leverage increases investment opportunity, it also increases investment risk.
	During the same 12-month period, the average return at NAV of the 24 closed end funds in Morningstar’s Closed End High Yield Municipal category (which may or may not be leveraged) was -0.62%, and the average return at market price of the closed-end funds within the same Morningstar category was 0.96%.
	The shares of the Fund were selling at a 12.14% discount to NAV on April 30, 2024. Comparatively, the shares of the Fund were selling at a 14.29% discount to NAV on April 30, 2023. On

*	Mr. van Roden and Mr. Vadlamani became portfolio managers of the Fund effective February 28, 2024.

2Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

	April 30, 2024, the standardized 30-day SEC yield of the Fund’s shares was 4.49%.**
Q	Which of your investment strategies or individual portfolio holdings contributed positively to performance during the 12-month period ended April 30, 2024 ?
A	In sector terms, the portfolio’s positioning in the education, hospitals and water & sewer sectors contributed positively to the Fund’s relative returns during the 12-month period. Puerto Rico General Obligation debt contributed positively to benchmark-relative returns, as strong investor demand drove spreads tighter. The water and sewer sectors within Puerto Rico also saw improved bids as positive economic data supported investor demand.
	The reduction in the Fund’s total managed assets financed by leverage in June 2023 helped relative returns, as the income component of the Fund’s total return improved. In addition, the Fund was able to divest lower yielding securities during the deleveraging process.
Q	Which investment strategies or individual portfolio holdings detracted from the Fund’s benchmark-relative performance results during the 12-month period ended April 30, 2024?
A	Interest expense relating to the Fund’s employment of leverage detracted from the Fund’s benchmark-relative returns during the first four months of the 12-month period, due to a significant increase in short term interest rates. The interest expense on the leverage exceeded the aggregate yield of the Fund’s portfolio during that period. Subsequently, the Fund reduced the amount of its total managed assets financed by leverage, which had a positive impact on net portfolio income.
	During the 12-month period, we made the decision to divest from a rural California municipal bond. This bond was under-performing as it failed to meet bond covenant requirements, resulting in distressed pricing and adversely affecting the Fund’s relative benchmark performance.

**	The 30-day SEC yield is a standardized formula that is based on the hypothetical annualized earning power (investment income only) of the Fund’s portfolio securities during the period indicated.

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/243

---

---

Table of Contents

Q	Did the Fund’s distributions** to stockholders change during the 12-month period ended April 30, 2024?
A	The Fund’s monthly distribution rate increased from $0.0425 per share in April 2023, to $0.0500 per share in April 2024.
Q	How did the level of leverage in the Fund change during the 12-month period ended April 30, 2024?
A	The Fund employs leverage through a credit agreement. (See Note 7 in the Notes to Financial Statements.) On April 30, 2024, 11.0% of the Fund’s total managed assets were financed by leverage obtained through the credit agreement, compared with 30.4% of the Fund’s total managed assets financed by leverage at the start of the 12-month period on May 1, 2023. During the 12-month period, the Fund decreased the amount of funds borrowed under the credit agreement by a total of $66 million to $26 million as of April 30, 2024. The percentage of the Fund’s managed assets financed by leverage decreased during the 12-month period due to the decrease in the amount of funds borrowed by the Fund. The interest rate on the Fund's leverage increased by 47 basis points from May 1, 2023 to April 30, 2024.
Q	Did the Fund have any exposure to derivatives during the 12- month period ended April 30, 2024?
A	Yes, we invested the Fund’s portfolio in interest rate futures contracts during the period, which were used to manage the duration during the Fund’s deleveraging.
Q	What is your investment outlook, and how is the Fund positioned heading into its new fiscal year?
A	We have continued to prefer investments in hospital-related issues, since the sector has historically had very low default rates. The revenue received by hospitals has remained diverse, coming from a combination of Medicare, Medicaid, private insurers, and self-payors. The Fund is also overweight to tobacco Master Settlement Agreement (MSA) bonds, due in part to the fact that the sector has experienced a below market rate of default compared to other municipal sectors. Tobacco bond revenues have provided substantial funding for the advancement

**	Distributions are not guaranteed.

4Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

	of public health and other similar programs to state and local governments that signed the tobacco MSA.
	In addition, the Fund is slightly underweight relative to the benchmark to bonds issued by the Commonwealth of Puerto Rico. The Fund is underweight select sectors within the Puerto Rico tax-exempt market based on current valuation levels and the potential for elevated volatility. However, the Commonwealth’s sales tax collections are up 5.2% year-over-year. This increased revenue has supported fundamentals and has led to our gradually improving outlook on Puerto Rico tax-exempt debt.
	The Fund is also underweight to state general obligation issues, which have tended to be sensitive to political considerations, as certain state governments may have lower flexibility to raise taxes due to constituents’ preferences, thus limiting their ability to increase revenues.
	We anticipate that the shifting interest-rate outlook will continue to impact near-term market performance, given the data dependent nature of US Federal Reserve System (Fed) policy. However, slowing consumer spending and decelerating activity in the housing market may indicate that the Fed is moving closer to the point at which it can conclude its monetary tightening cycle. If this turns out to be the case, we believe investors may turn their attention to the positive fundamental traits of the high yield municipal market, including its current low default rate and the continued decline in new-issue supply. We are also encouraged by the opportunities afforded by the compelling yields in the investment-grade municipal bond space.
	As is always the case, headline news events have had a minimal effect on our day-to-day approach to managing the portfolio. Our goal is to invest the Fund in what we believe are fundamentally sound credits representing relative value opportunities, while maintaining an appropriate level of risk management. We also seek to avoid experiencing defaults in the Fund through our emphasis on fundamental research. We believe this steady, long term approach remains the most effective way to identify opportunities and to help minimize the risk associated with investing in the high-yield municipal market.

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/245

---

---

Table of Contents

Please refer to the Schedule of Investments on pages 14  - 20  for a full listing of Fund securities.

The Fund is a diversified, closed-end fund. The Fund's primary investment objective is to provide holders with a high level of current income exempt from regular federal income tax. As a secondary investment objective, the Fund may seek capital appreciation to the extent consistent with its primary investment objective. The Fund invests in a professionally managed portfolio of municipal securities from across the United States.

All investments are subject to risk, including the possible loss of principal. In the past several years, financial markets have experienced increased volatility and heightened uncertainty. The market prices of securities may go up or down, sometimes rapidly or unpredictably, due to general market conditions, such as real or perceived adverse economic, political, or regulatory conditions, recessions, inflation, changes in interest or currency rates, lack of liquidity in the bond markets, the spread of infectious illness or other public health issues, armed conflict including Russia's military invasion of Ukraine, sanctions against Russia, other nations or individuals or companies and possible countermeasures, market disruptions caused by tariffs, trade disputes or other government actions, or adverse investor sentiment. These conditions may continue, recur, worsen or spread.

Investments in high-yield or lower-rated securities are subject to greater-than-average risk.

The Fund may invest in securities of issuers that are in default or in bankruptcy.

A portion of income may be subject to state, federal, and/or alternative minimum tax. Capital gains, if any, are subject to a capital gains tax.

When interest rates rise, the prices of debt securities held by the Fund will generally fall. Conversely, when interest rates fall the prices of debt securities held by the Fund generally will rise. A general rise in interest rates could adversely affect the price and liquidity of fixed-income securities.

The value of municipal securities can be adversely affected by changes in financial condition of municipal issuers, lower revenues, and regulatory and political developments. By concentrating in municipal securities, the Fund is more susceptible to adverse economic, political or regulatory developments than is a portfolio that invests more broadly.

Investments in the Fund are subject to possible loss due to the financial failure of the issuers of the underlying securities and the issuers’ inability to meet their debt obligations.

6Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

The Fund may invest in illiquid securities. Illiquid securities may be difficult to dispose of at a price reflective of their value at the times when the Fund believes it is desirable to do so and the market price of illiquid securities is generally more volatile than that of more liquid securities. Illiquid securities also are more difficult to value, and investment of the Fund’s assets in illiquid securities may restrict the Fund’s ability to take advantage of market opportunities.

The Fund uses leverage, which entails specific risks, to seek a higher return. The Fund may source leverage through a number of methods, including through a credit agreement. Leverage generally magnifies the effect of any increase or decrease in the value of the Fund’s underlying assets and creates investment risk with respect to a larger pool of assets than the Fund would otherwise have, potentially resulting in the loss of all assets. Leverage creates significant risks, including the risk that the Fund’s incremental income or capital appreciation for investments purchased with the proceeds of leverage will not be sufficient to cover the cost of the leverage, which may adversely affect the return for the holders of common shares.

The Fund is required to maintain certain regulatory and other asset coverage requirements in connection with the use of leverage. In order to maintain required asset coverage levels, the Fund may be required to reduce the amount of leverage employed, alter the composition of the Fund’s investment portfolio or take other actions at what might be inopportune times in the market. Such actions could reduce the net earnings or returns to stockholders over time, which is likely to result in a decrease in the market value of the Fund’s shares.

Prepayment risk is the chance that an issuer may exercise its right to prepay its security, if falling interest rates prompt the issuer to do so. Forced to reinvest the unanticipated proceeds at lower interest rates, the Fund would experience a decline in income and lose the opportunity for additional price appreciation.

In accordance with the Fund's charter, the Fund intends to terminate on the close of business on August 31, 2033 (the “Termination Date”). In addition, as of a date within twelve months preceding the Termination Date, the Board of the Fund may (but is not required to) cause the Fund to conduct a tender offer to all common stockholders. In connection with the tender offer and/or termination as described in the Fund’s prospectus, the Fund will incur transaction costs in connection with dispositions of portfolio securities. The Fund may be required to sell portfolio securities when it otherwise would not, including at times when market conditions are not favorable, which may cause the Fund to lose money. In connection with the tender offer and/or termination as described in the Fund's prospectus, the Fund may begin liquidating all or a portion of its portfolio, and may deviate from its investment policies and may not achieve its investment objective.

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/247

---

---

Table of Contents

These risks may increase share price volatility.

Any information in this stockholder report regarding market or economic trends or the factors influencing the Fund’s historical or future performance are statements of opinion as of the date of this report. Past performance is no guarantee of future results.

8Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

Portfolio Summary  |  4/30/24 

Portfolio Diversification

---

(As a percentage of total investments)*

State Diversification

---

(As a percentage of total investments)*

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/249

---

---

Table of Contents

Portfolio Summary  |  4/30/24 (continued)

Portfolio Maturity

---

(As a percentage of total investments)*

10 Largest Holdings

---

(As a percentage of total investments)*
1.	Tobacco Settlement Finance Authority, Series A, 4.306%, 6/1/49	5.02%
2.	Buckeye Tobacco Settlement Financing Authority, Senior Class 2, Series B-2, 5.00%, 6/1/55	4.95
3.	Arkansas Development Finance Authority, Big River Steel Project, 4.50%, 9/1/49 (144A)	3.92
4.	Metropolitan Pier & Exposition Authority, McCormick Place Expansion, 4.00%, 6/15/50	3.71
5.	Erie Tobacco Asset Securitization Corp., Asset-Backed, Series A, 5.00%, 6/1/45	3.63
6.	Iowa Finance Authority, Alcoa Inc. Projects, 4.75%, 8/1/42	3.59
7.	Tobacco Settlement Financing Corp., Series A-1, 6.706%, 6/1/46	3.57
8.	Puerto Rico Commonwealth Aqueduct & Sewer Authority, Series A, 5.00%, 7/1/47 (144A)	3.30
9.	Commonwealth of Puerto Rico, Restructured Series A-1, 4.00%, 7/1/37	3.20
10.	New York Counties Tobacco Trust IV, Settlement pass through, Series A, 5.00%, 6/1/45	3.15

*  Excludes short-term investments and all derivative contracts except for options purchased. The Fund is actively managed, and current holdings may be different. The holdings listed should not be considered recommendations to buy or sell any securities.

10Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

Prices and Distributions  |  4/30/24

Market Value per Share^

	4/30/24	4/30/23
Market Value	$11.00	$10.68
Discount	(12.14)%	(14.29)%

Net Asset Value per Share^

	4/30/24	4/30/23
Net Asset Value	$12.52	$12.46

Distributions per Share

	Net Investment Income	Short-Term Capital Gains	Long-Term Capital Gains	Tax Return of Capital
5/1/23 – 4/30/24	$0.5117	$—	$—	$0.0118

Yields

	4/30/24	4/30/23
30-Day SEC Yield	4.49%	3.75%

The data shown above represents past performance, which is no guarantee of future results.

^ Net asset value and market value are published daily on the Fund's website at www.amundi.com/us.

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2411

---

---

Table of Contents

Performance Update  |  4/30/24

Investment Returns

---

The mountain chart on the right shows the change in market value, including reinvestment of dividends and distributions, of a $10,000 investment made in common shares of Pioneer Municipal High Income Opportunities Fund, Inc. during the periods shown, compared to that of the Bloomberg Municipal Bond Index and Bloomberg U.S. Municipal High Yield Bond Index. (Growth of $10,000 comparisons for the Fund begin on August 6, 2021. Growth of $10,000 comparisons for the Bloomberg indices begin on August 31, 2021.)

Average Annual Total Return (As of April 30, 2024)
Period	Net Asset Value (NAV)	Market Price	Bloom- berg Municipal Bond Index	Bloom- berg US Municipal High Yield Bond Index
Life of Fund (8/5/21)*	-11.61%	-15.69%	-1.73%	-1.48%
1 Year	5.58	8.22	2.08	6.63

Value of $10,000 Investment

Call 1-800-710-0935 or visit www.amundi.com/us for the most recent month-end performance results. Current performance may be lower or higher than the performance data quoted.

Performance data shown represents past performance. Past performance is no guarantee of future results. Investment return and market price will fluctuate, and your shares may trade below NAV due to such factors as interest rate changes and the perceived credit quality of borrowers.

Total investment return does not reflect broker sales charges or commissions. All performance is for common shares of the Fund.

Shares of closed-end funds, unlike open-end funds, are not continuously offered. There is a one-time public offering and, once issued, shares of closed-end funds are bought and sold in the open market through a stock exchange and frequently trade at prices lower than their NAV. NAV per common share is total assets less total liabilities, which include preferred shares or borrowings, as applicable, divided by the number of common shares outstanding.

When NAV is lower than market price, dividends are assumed to be reinvested at the greater of NAV or 95% of the market price.When NAV is higher, dividends are assumed to be reinvested at prices obtained through open-market purchases under the Fund’s dividend reinvestment plan.

The performance table and graph do not reflect the deduction of fees and taxes that a stockholders would pay on Fund distributions or the sale of Fund shares. Had these fees and taxes been reflected, performance would have been lower.

The Bloomberg Municipal Bond Index is an unmanaged, broad measure of the municipal bond market.

12Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

Performance Update  |  4/30/24

The Bloomberg U.S. Municipal High Yield Bond Index is unmanaged, totals over $26 billion in market value and maintains over 1,300 securities. Municipal bonds in this index have the following requirements: maturities of one year or greater, sub investment grade (below Baa or non-rated), fixed coupon rate, issue date later than 12/31/90, deal size over $20 million, maturity size of at least $3 million. Index returns are calculated monthly, assume reinvestment of dividends and do not reflect any fees, expenses or sales charges. The indices do not employ leverage. You cannot invest directly in an index.

* Date of the Fund's inception and initial public offering. The Fund commenced operations on August 6, 2021.

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2413

---

---

Table of Contents

Schedule of Investments  |  4/30/24 

Principal Amount USD ($)						Value
	UNAFFILIATED ISSUERS — 108.7%
	Municipal Bonds — 108.4% of Net Assets(a)
	Arizona — 3.0%
1,675,000	Arizona Industrial Development Authority, Doral Academy Nevada Fire Mesa, Series A, 5.00%, 7/15/49					$  1,577,465
1,000,000	Arizona Industrial Development Authority, Doral Academy Of Northern Nevada Project, Series A, 4.00%, 7/15/51 (144A)					762,340
950,000	Arizona Industrial Development Authority, Doral Academy Of Northern Nevada Project, Series A, 4.00%, 7/15/56 (144A)					689,253
4,000,000	Maricopa County Industrial Development Authority, Commercial Metals Company, 4.00%, 10/15/47 (144A)					3,398,240
	Total Arizona					$6,427,298
	Arkansas — 5.1%
9,500,000	Arkansas Development Finance Authority, Big River Steel Project, 4.50%, 9/1/49 (144A)					$  8,994,790
1,750,000	Arkansas Development Finance Authority, Green Bond, 5.45%, 9/1/52					1,724,293
	Total Arkansas					$10,719,083
	California — 4.8%
1,000,000	California County Tobacco Securitization Agency, Golden Gate Tobacco Settlement, Series A, 5.00%, 6/1/47					$    943,890
750,000	California Municipal Finance Authority, Westside Neighborhood School Project, Series A, 6.375%, 6/15/64 (144A)					768,487
1,000,000	California Statewide Communities Development Authority, Baptist University, Series A, 5.00%, 11/1/41 (144A)					988,170
2,315,000	California Statewide Communities Development Authority, Loma Linda University Medical Center, Series A, 5.25%, 12/1/56 (144A)					2,319,861
795,000	Chino Community Facilities District, Series 3, 5.00%, 9/1/44					806,464
740,000	Chino Community Facilities District, Series 3, 5.00%, 9/1/54					737,647
5,220,000	City of Oroville, Oroville Hospital, 5.25%, 4/1/54					3,555,499
	Total California					$10,120,018
	Colorado — 9.4%
5,180,000	Aerotropolis Regional Transportation Authority, 4.25%, 12/1/41					$  4,626,880
3,500,000	Aerotropolis Regional Transportation Authority, 4.375%, 12/1/52					2,865,205

The accompanying notes are an integral part of these financial statements.

14Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

Principal Amount USD ($)						Value
	Colorado — (continued)
2,620,000	Aerotropolis Regional Transportation Authority, 5.00%, 12/1/51					$  2,437,360
3,000,000	Colorado High Performance Transportation Enterprise, 5.00%, 12/31/56					2,931,180
1,897,000(b)	Cottonwood Highlands Metropolitan District No. 1, Series A, 5.00%, 12/1/49					1,763,091
2,000,000	Dominion Water & Sanitation District, 5.875%, 12/1/52					1,962,480
3,475,000	Prairie Center Metropolitan District No 3, Series A, 5.00%, 12/15/41 (144A)					3,341,212
	Total Colorado					$19,927,408
	Delaware — 0.3%
1,015,000	Delaware State Economic Development Authority, Aspira of Delaware Charter, 4.00%, 6/1/57					$    672,844
	Total Delaware					$672,844
	Florida — 4.4%
1,335,000	Capital Trust Authority, Series A, 5.50%, 12/15/33 (144A)					$  1,336,832
1,320,000	Capital Trust Authority, Series A, 6.50%, 12/15/53 (144A)					1,341,225
2,000,000	Florida Development Finance Corp., Brightline Florida Passenger Rail Project, 5.50%, 7/1/53					2,079,980
1,000,000(c)	Florida Development Finance Corp., Brightline Florida Passenger Rail Project, 12.00%, 7/15/32 (144A)					1,028,490
4,425,000	Florida Development Finance Corp., Glenridge On Palmer Ranch Project, 5.00%, 6/1/51 (144A)					3,474,289
	Total Florida					$9,260,816
	Illinois — 6.0%
4,260,000(b)	Chicago Board of Education, Series A, 5.00%, 12/1/42					$  4,113,584
9,500,000	Metropolitan Pier & Exposition Authority, McCormick Place Expansion, 4.00%, 6/15/50					8,532,425
	Total Illinois					$12,646,009
	Indiana — 1.7%
1,250,000	City of Valparaiso, Pratt Paper LLC Project, 5.00%, 1/1/54 (144A)					$  1,265,100
2,500,000	Indiana Finance Authority, Multipurpose Educational Facilities, Avondale Meadows Academy Project, 5.375%, 7/1/47					2,372,750
	Total Indiana					$3,637,850

The accompanying notes are an integral part of these financial statements.

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2415

---

---

Table of Contents

Schedule of Investments  |  4/30/24 (continued)

Principal Amount USD ($)						Value
	Iowa — 3.9%
8,600,000	Iowa Finance Authority, Alcoa Inc. Projects, 4.75%, 8/1/42					$  8,254,108
	Total Iowa					$8,254,108
	Massachusetts — 0.9%
2,000,000	Massachusetts Development Finance Agency, Lowell General Hospital, Series G, 5.00%, 7/1/44					$  1,942,840
	Total Massachusetts					$1,942,840
	Minnesota — 0.6%
1,430,000	City of Rochester, Rochester Math & Science Academy, Series A, 5.125%, 9/1/38					$  1,276,246
	Total Minnesota					$1,276,246
	New Jersey — 0.9%
1,865,000	Tobacco Settlement Financing Corp., Series B, 5.00%, 6/1/46					$  1,882,718
	Total New Jersey					$1,882,718
	New York — 26.8%
5,300,000	Chautauqua Tobacco Asset Securitization Corp., 5.00%, 6/1/48					$  5,115,136
1,000,000	Dutchess County Local Development Corp., Health Quest Systems Inc., Series B, 5.00%, 7/1/46					965,560
8,885,000	Erie Tobacco Asset Securitization Corp., Asset-Backed, Series A, 5.00%, 6/1/45					8,336,085
3,505,000	Nassau County Tobacco Settlement Corp., Asset-Backed, Series A-3, 5.00%, 6/1/35					3,332,764
2,895,000	Nassau County Tobacco Settlement Corp., Asset-Backed, Series A-3, 5.125%, 6/1/46					2,692,697
1,730,000	New York Counties Tobacco Trust IV, Series A, 5.00%, 6/1/42					1,622,429
7,915,000	New York Counties Tobacco Trust IV, Settlement pass through, Series A, 5.00%, 6/1/45					7,246,262
5,000,000	New York Transportation Development Corp., Series A, 5.25%, 1/1/50					4,977,350
3,000,000	New York Transportation Development Corp., Green Bond, 5.375%, 6/30/60					3,132,600
305,000	Suffolk Regional Off-Track Betting Co., 5.75%, 12/1/44					310,200
900,000	Suffolk Regional Off-Track Betting Co., 6.00%, 12/1/53					909,000
6,715,000	TSASC, Inc., Series B, 5.00%, 6/1/48					5,993,003

The accompanying notes are an integral part of these financial statements.

16Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

Principal Amount USD ($)						Value
	New York — (continued)
8,000,000	Westchester County Local Development Corp., Purchase Senior Learning Community, 4.50%, 7/1/56 (144A)					$  6,616,720
5,775,000	Westchester County Local Development Corp., Purchase Senior Learning Community, 5.00%, 7/1/56 (144A)					5,294,924
	Total New York					$56,544,730
	Ohio — 5.4%
12,500,000	Buckeye Tobacco Settlement Financing Authority, Senior Class 2, Series B-2, 5.00%, 6/1/55					$ 11,366,625
	Total Ohio					$11,366,625
	Oklahoma — 2.8%
5,900,000	Tulsa Airports Improvement Trust, Series C, 5.50%, 12/1/35					$  5,902,242
	Total Oklahoma					$5,902,242
	Pennsylvania — 2.4%
600,000	Allentown Commercial and Industrial Development Authority, 5.75%, 6/15/43					$    614,472
1,600,000	Allentown Commercial and Industrial Development Authority, 6.00%, 6/15/53					1,618,368
750,000	Philadelphia Authority for Industrial Development, 4.00%, 6/1/41					617,985
2,500,000(c)	Philadelphia Authority for Industrial Development, 5.125%, 12/15/44 (144A)					2,258,425
	Total Pennsylvania					$5,109,250
	Puerto Rico — 15.9%
7,673,960(b)	Commonwealth of Puerto Rico, Restructured Series A-1, 4.00%, 7/1/37					$  7,347,049
1,796,000(b)	Commonwealth of Puerto Rico, Restructured Series A-1, 4.00%, 7/1/41					1,670,981
3,624,000(b)	Commonwealth of Puerto Rico, Restructured Series A-1, 4.00%, 7/1/46					3,267,543
1,900,000	GDB Debt Recovery Authority of Puerto Rico, 7.50%, 8/20/40					1,828,750
3,220,000	Puerto Rico Commonwealth Aqueduct & Sewer Authority, Series A, 5.00%, 7/1/37 (144A)					3,365,705
7,500,000	Puerto Rico Commonwealth Aqueduct & Sewer Authority, Series A, 5.00%, 7/1/47 (144A)					7,591,425

The accompanying notes are an integral part of these financial statements.

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2417

---

---

Table of Contents

Schedule of Investments  |  4/30/24 (continued)

Principal Amount USD ($)						Value
	Puerto Rico — (continued)
6,844,000	Puerto Rico Sales Tax Financing Corp. Sales Tax Revenue, Series A1, 4.75%, 7/1/53					$  6,690,010
1,868,000	Puerto Rico Sales Tax Financing Corp. Sales Tax Revenue, Series A1, 5.00%, 7/1/58					1,863,797
	Total Puerto Rico					$33,625,260
	Texas — 1.3%
3,000,000	City of Houston Airport System Revenue, 4.00%, 7/15/41					$  2,788,560
	Total Texas					$2,788,560
	Virginia — 3.9%
9,615,000	Tobacco Settlement Financing Corp., Series A-1, 6.706%, 6/1/46					$  8,191,595
	Total Virginia					$8,191,595
	West Virginia — 5.5%
15,000,000	Tobacco Settlement Finance Authority, Series A, 4.306%, 6/1/49					$ 11,529,600
	Total West Virginia					$11,529,600
	Wisconsin — 3.4%
1,115,000	Public Finance Authority, Coral Academy Science Reno, 5.00%, 6/1/39 (144A)					$  1,048,022
8,000,000	Public Finance Authority, Searstone CCRC Project, 4.00%, 6/1/41 (144A)					6,157,360
	Total Wisconsin					$7,205,382
	Total Municipal Bonds (Cost $223,731,197)					$229,030,482
	U.S. Government and Agency Obligations — 0.3% of Net Assets
700,000(d)	U.S. Treasury Bills, 5/21/24					$    697,950
	Total U.S. Government and Agency Obligations (Cost $697,946)					$697,950
	TOTAL INVESTMENTS IN UNAFFILIATED ISSUERS — 108.7% (Cost $224,429,143)					$229,728,432
	OTHER ASSETS AND LIABILITIES — (8.7)%					$(18,388,742)
	net assets — 100.0%					$211,339,690

The accompanying notes are an integral part of these financial statements.

18Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

(144A)

The resale of such security is exempt from registration under Rule 144A of the Securities Act of 1933. Such securities may be resold normally to qualified institutional buyers. At April 30, 2024, the value of these securities amounted to $62,040,870, or 29.4% of net assets.

(a)	Consists of Revenue Bonds unless otherwise indicated.
(b)	Represents a General Obligation Bond.
(c)	The interest rate is subject to change periodically. The interest rate and/or reference index and spread shown at April 30, 2024.
(d)	Security issued with a zero coupon. Income is recognized through accretion of discount.

The concentration of investments as a percentage of total investments by type of obligation/market sector is as follows:

Revenue Bonds:
Tobacco Revenue	29.7%
Development Revenue	16.1
Health Revenue	13.2
Transportation Revenue	10.5
Education Revenue	7.8
Other Revenue	6.3
Water Revenue	5.6
General Revenue	2.9
	92.1%
General Obligation Bonds:	7.9%
	100.0%

FUTURES CONTRACTS
FIXED INCOME INDEX FUTURES CONTRACTS

Number of Contracts Long	Description	Expiration Date	Notional Amount	Market Value	Unrealized (Depreciation)
38	U.S. Ultra Bond (CBT)	6/18/24	$4,842,135	$4,543,375	$(298,760)
TOTAL FUTURES CONTRACTS			$4,842,135	$4,543,375	$(298,760)
CBT	Chicago Board of Trade.

Purchases and sales of securities (excluding short-term investments) for the year ended April 30, 2024, aggregated $99,496,705 and $168,664,393, respectively.

The accompanying notes are an integral part of these financial statements.

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2419

---

---

Table of Contents

Schedule of Investments  |  4/30/24 (continued)

At April 30, 2024, the net unrealized depreciation on investments based on cost for federal tax purposes of $229,889,717 was as follows:

Aggregate gross unrealized appreciation for all investments in which there is an excess of value over tax cost	$11,217,256
Aggregate gross unrealized depreciation for all investments in which there is an excess of tax cost over value	(11,378,541)
Net unrealized depreciation	$(161,285)

Various inputs are used in determining the value of the Fund’s investments. These inputs are summarized in the three broad levels below.

Level 1	–	unadjusted quoted prices in active markets for identical securities.
Level 2	–	other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risks, etc.). See Notes to Financial Statements — Note 1A.
Level 3	–	significant unobservable inputs (including the Adviser’s own assumptions in determining fair value of investments). See Notes to Financial Statements — Note 1A.

The following is a summary of the inputs used as of April 30, 2024 in valuing the Fund’s investments:

	Level 1	Level 2	Level 3	Total
Municipal Bonds	$—	$229,030,482	$—	$229,030,482
U.S. Government and Agency Obligations	—	697,950	—	697,950
Total Investments in Securities	$—	$229,728,432	$—	$229,728,432
Other Financial Instruments
Credit Agreement(a)	$—	$(26,000,000)	$—	$(26,000,000)
Net unrealized depreciation on futures contracts	(298,760)	—	—	(298,760)
Total Other Financial Instruments	$(298,760)	$(26,000,000)	$—	$(26,298,760)

(a)	The Fund may hold liabilities in which the fair value approximates the carrying amount for financial statement purposes.

During the year ended April 30, 2024, there were no transfers in or out of Level 3.

The accompanying notes are an integral part of these financial statements.

20Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

Statement of Assets and Liabilities  |  4/30/24

ASSETS:
Investments in unaffiliated issuers, at value (cost $224,429,143)	$229,728,432
Cash	9,963,902
Futures collateral	287,380
Due from broker for futures	39,188
Distribution paid in advance	844,263
Receivables —
Investment securities sold	1,044,360
Interest	4,213,680
Total assets	$246,121,205
LIABILITIES:
Payables —
Credit agreement	$26,000,000
Investment securities purchased	7,608,465
Distributions	844,263
Directors’ fees	765
Interest expense	133,581
Variation margin for futures contracts	39,188
Management fees	25,953
Administrative expenses	14,809
Accrued expenses	114,491
Total liabilities	$34,781,515
NET ASSETS APPLICABLE TO COMMON STOCKHOLDERS:
Paid-in capital	$333,335,508
Distributable earnings (loss)	(121,995,818)
Net assets	$211,339,690
NET ASSET VALUE PER COMMON SHARE:
No par value  Based on $211,339,690/16,885,273 common shares	$12.52

The accompanying notes are an integral part of these financial statements.

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2421

---

---

Table of Contents

Statement of Operations FOR THE YEAR ENDED 4/30/24

INVESTMENT INCOME:
Interest from unaffiliated issuers	$13,308,597
Total Investment Income		$13,308,597
EXPENSES:
Management fees	$1,925,610
Administrative expenses	67,202
Transfer agent fees	15,337
Stockholder communications expense	33,436
Custodian fees	2,202
Professional fees	131,757
Printing expense	12,029
Officers’ and Directors’ fees	9,405
Insurance expense	4,270
Interest expense	2,084,065
Miscellaneous	56,714
Total expenses		$4,342,027
Net investment income		$8,966,570
REALIZED AND UNREALIZED GAIN (LOSS) ON INVESTMENTS:
Net realized gain (loss) on:
Reimbursement by the Adviser	$708,565
Investments in unaffiliated issuers	(12,450,899)
Futures contracts	(463,521)	$(12,205,855)
Change in net unrealized appreciation (depreciation) on:
Investments in unaffiliated issuers	$13,325,327
Futures contracts	(298,760)	$13,026,567
Net realized and unrealized gain (loss) on investments		$820,712
Net increase in net assets resulting from operations		$9,787,282

The accompanying notes are an integral part of these financial statements.

22Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

Statements of Changes in Net Assets

	Year Ended 4/30/24	Year Ended 4/30/23
FROM OPERATIONS:
Net investment income (loss)	$8,966,570	$8,280,337
Net realized gain (loss) on investments	(12,205,855)	(88,569,668)
Change in net unrealized appreciation (depreciation) on investments	13,026,567	56,347,021
Net increase (decrease) in net assets resulting from operations	$9,787,282	$(23,942,310)
DISTRIBUTIONS TO COMMON STOCKHOLDERS:
($0.51 and $0.53 per share, respectively)	$(8,645,872)	$(8,982,965)
Tax Return Of Capital To Common Stockholders:
($0.01 and $0.15 per share, respectively)	$(193,568)	$(2,490,578)
Total distributions to common stockholders	$(8,839,440)	$(11,473,543)
Net increase (decrease) in net assets applicable to common stockholders	$947,842	$(35,415,853)
NET ASSETS APPLICABLE TO COMMON STOCKHOLDERS:
Beginning of year	$210,391,848	$245,807,701
End of year	$211,339,690	$210,391,848

The accompanying notes are an integral part of these financial statements.

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2423

---

---

Table of Contents

Statement of Cash Flows FOR THE YEAR ENDED 4/30/24 

Cash Flows From Operating Activities
Net increase in net assets resulting from operations	$9,787,282
Adjustments to reconcile net decrease in net assets resulting from operations to net cash and restricted cash from operating activities:
Purchases of investment securities	$(95,792,448)
Proceeds from disposition and maturity of investment securities	173,235,445
Net sales of short term investments	(692,955)
Net accretion and amortization of discount/premium on investment securities	(494,039)
Reimbursement by the Adviser	(708,565)
Net realized loss on investments in unaffiliated issuers	12,450,899
Change in unrealized depreciation on investments in unaffiliated issuers	(13,325,327)
Increase in due from broker for futures	(39,188)
Decrease in interest receivable	1,118,722
Increase in distributions paid in advance	(126,639)
Increase in variation margin for futures contracts	39,188
Decrease in management fees payable	(7,140)
Decrease in directors’ fees payable	(1,251)
Increase in administrative expenses payable	1,619
Decrease in accrued expenses payable	(5,398)
Net cash and restricted cash from operating activities	$85,440,205
Cash Flows from Financing Activities:
Borrowings repaid	(66,000,000)
Overdraft due to custodian	(175,365)
Increase in interest expense payable	(300,757)
Distributions to stockholders	(8,712,801)
Net cash flows used in financing activities	$(75,188,923)
NET INCREASE (DECREASE) IN CASH AND RESTRICTED CASH	$10,251,282
Cash and Restricted Cash:
Beginning of year*	$—
End of year*	$10,251,282
Cash Flow Information:
Cash paid for interest	$2,384,822

*	The following table provides a reconciliation of cash and restricted cash reported Assets and Liabilities that sum to the total of the same such amounts shown in the Statement of Cash Flows:

	Year Ended 4/30/24	Year Ended 4/30/23
Cash	$9,963,902	$—
Restricted cash	287,380	—
Total cash and restricted cash shown in the Statement of Cash Flows	$10,251,282	$—

The accompanying notes are an integral part of these financial statements

24Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

Financial Highlights  

	Year Ended 4/30/24	Year Ended 4/30/23	Period From 8/6/21* to 4/30/22
Per Share Operating Performance
Net asset value, beginning of period	$12.46	$14.56	$20.00
Increase (decrease) from investment operations:
Net investment income (loss)(a)	$0.53	$0.49	$0.28
Net realized and unrealized gain (loss) on investments	0.05	(1.91)	(5.37)
Net increase (decrease) from investment operations	$0.58	$(1.42)	$(5.09)
Distributions to stockholders:
Net investment income	$(0.51)	$(0.53)**	$(0.27)
Tax return of capital	(0.01)	(0.15)	(0.08)
Total distributions	$(0.52)	$(0.68)	$(0.35)
Net increase (decrease) in net asset value	$0.06	$(2.10)	$(5.44)
Net asset value, end of period	$12.52	$12.46	$14.56
Market value, end of period	$11.00	$10.68	$12.61
Total return at net asset value(b)	5.58%(c)	(9.14)%	(25.60)%(d)
Total return at market value(b)	8.22%	(10.08)%	(35.56)%(d)
Ratios to average net assets of stockholders:
Total expenses plus interest expense(e)	2.10%	3.03%	1.30%(f)
Net investment income available to stockholders	4.33%	3.79%	2.03%(f)
Portfolio turnover rate	42%	98%	95%(d)
Net assets, end of period (in thousands)	$211,340	$210,392	$245,808
Ratios with no waiver of fees and assumption of expenses by the Adviser and no reduction for fees paid indirectly:
Total expenses to average net assets	2.10%	3.17%	1.49%(f)
Net investment income (loss) to average net assets	4.33%	3.65%	1.84%(f)
Total amount of debt outstanding (in thousands)	$26,000	$92,000	$139,455
Asset coverage per $1,000 of indebtedness	$9,128	$3,287	$2,763

*	The Fund commenced operations on August 6, 2021.
**	The amount of distributions made to stockholders during the period was in excess of the net investment income earned by the Fund during the period. The Fund has accumulated undistributed net investment income which is part of the Fund’s net asset value (“NAV”). A portion of this accumulated net investment income was distributed to stockholders during the period. A decrease in distributions may have a negative effect on the market value of the Fund’s shares.
(a)	The per-share data presented above is based on the average common shares outstanding for the period presented.

The accompanying notes are an integral part of these financial statements.

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2425

---

---

Table of Contents

Financial Highlights  (continued)

(b)	Total investment return is calculated assuming a purchase of common shares at the current net asset value or market value on the first day and a sale at the current net asset value or market value on the last day of the periods reported. Dividends and distributions, if any, are assumed for purposes of this calculation to be reinvested at prices obtained under the Fund’s dividend reinvestment plan. Total investment return does not reflect brokerage commissions. Past performance is not a guarantee of future results.
(c)	For the year ended April 30, 2024, the Fund's total return includes a voluntarily reimbursement by the Adviser (see Notes to the Financial Statements-Note 1.B.). If the Fund had not been reimbursed by the Adviser the total return would have been 5.16%.
(d)	Not annualized.
(e)	Includes interest expense of 1.01%, 1.79%, and 0.31%, respectively.
(f)	Annualized.

The accompanying notes are an integral part of these financial statements.

26Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

Notes to Financial Statements  |  4/30/24

1. Organization and Significant Accounting Policies

Pioneer Municipal High Income Opportunities Fund, Inc. (the “Fund”) is a newly organized, diversified, closed-end management investment company. The Fund is organized as a Maryland corporation. Prior to commencing operations on August 6, 2021, the Fund had no operations other than matters related to its organization and registration under the Investment Company Act of 1940, as amended (the “1940 Act”). The Fund issued 5,000 common shares on June 15, 2021, 15,000,000 common shares on August 5, 2021, 1,000,000 shares on September 14, 2021, and 880,273 shares on September 21, 2021. The Fund’s primary investment objective is to provide holders of the Fund’s common stock (“Common Shares”) with a high level of current income exempt from regular federal income tax. As a secondary investment objective, the Fund may seek capital appreciation to the extent consistent with its primary investment objective. Distributions from sources other than interest income from the Fund’s portfolio of municipal securities, including capital gain distributions, are not exempt from regular federal income tax. There can be no assurance that the Fund will achieve its investment objectives.

Amundi Asset Management US, Inc., an indirect, wholly owned subsidiary of Amundi and Amundi’s wholly owned subsidiary, Amundi USA, Inc., serves as the Fund’s investment adviser (the “Adviser”).

The Fund is required to comply with Rule 18f-4 under the 1940 Act, which governs the use of derivatives by registered investment companies. Rule 18f-4 permits funds to enter into derivatives transactions (as defined in Rule 18f-4) and certain other transactions notwithstanding the restrictions on the issuance of “senior securities” under Section 18 of the 1940 Act. Rule 18f-4 requires a fund to establish and maintain a comprehensive derivatives risk management program, appoint a derivatives risk manager and comply with a relative or absolute limit on fund leverage risk calculated based on value-at-risk ("VaR"), unless the fund uses derivatives in only a limited manner (a "limited derivatives user"). The Fund is currently a limited derivatives user for purposes of Rule 18f-4.

The Fund is an investment company and follows investment company accounting and reporting guidance under U.S. Generally Accepted Accounting Principles (“U.S. GAAP”). U.S. GAAP requires the management of the Fund to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2427

---

---

Table of Contents

of income, expenses and gain or loss on investments during the reporting period. Actual results could differ from those estimates.

The following is a summary of significant accounting policies followed by the Fund in the preparation of its financial statements:

A.	Security Valuation
	The net asset value of the Fund is computed once daily, on each day the New York Stock Exchange (“NYSE”) is open, as of the close of regular trading on the NYSE.
	Fixed-income securities are valued by using prices supplied by independent pricing services, which consider such factors as market prices, market events, quotations from one or more brokers, Treasury spreads, yields, maturities and ratings, or may use a pricing matrix or other fair value methods or techniques to provide an estimated value of the security or instrument. A pricing matrix is a means of valuing a debt security on the basis of current market prices for other debt securities, historical trading patterns in the market for fixed-income securities and/or other factors. Non-U.S. debt securities that are listed on an exchange will be valued at the bid price obtained from an independent third party pricing service. When independent third party pricing services are unable to supply prices, or when prices or market quotations are considered to be unreliable, the value of that security may be determined using quotations from one or more broker-dealers.
	Securities for which independent pricing services or broker-dealers are unable to supply prices or for which market prices and/or quotations are not readily available or are considered to be unreliable are valued by a fair valuation team comprised of certain personnel of the Adviser. The Adviser is designated as the valuation designee for the Fund pursuant to Rule 2a-5 under the 1940 Act. The Adviser’s fair valuation team is responsible for monitoring developments that may impact fair valued securities.
	Inputs used when applying fair value methods to value a security may include credit ratings, the financial condition of the company, current market conditions and comparable securities. The Adviser may use fair value methods if it is determined that a significant event has occurred after the close of the exchange or market on which the security trades and prior to the determination of the Fund’s net asset value. Examples of a significant event might include political or economic news, corporate restructurings, natural disasters, terrorist activity or trading

28Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

	halts. Thus, the valuation of the Fund’s securities may differ significantly from exchange prices, and such differences could be material.
B.	Investment Income and Transactions
	Interest income, including interest on income-bearing cash accounts, is recorded on the accrual basis. Dividend and interest income are reported net of unrecoverable foreign taxes withheld at the applicable country rates and net of income accrued on defaulted securities.
	Discounts and premiums on purchase prices of debt securities are accreted or amortized, respectively, daily, into interest income on an effective yield to maturity basis with a corresponding increase or decrease in the cost basis of the security. Premiums and discounts related to certain mortgagebacked securities are amortized or accreted in proportion to the monthly paydowns.
	Interest and dividend income payable by delivery of additional shares is reclassified as PIK (payment-in-kind) income upon receipt and is included in interest and dividend income, respectively.
	Security transactions are recorded as of trade date. Gains and losses on sales of investments are calculated on the identified cost method for both financial reporting and federal income tax purposes.
	During the year ended April 30, 2024, the Fund realized a loss of $708,565 due to an operational error. The Adviser voluntarily reimbursed the Fund for this loss, which is reflected on the Statement of Operations as Reimbursement by the Adviser.
C.	Federal Income Taxes
	It is the Fund’s policy to comply with the requirements of the Internal Revenue Code applicable to regulated investment companies and to distribute all of its net taxable income and net realized capital gains, if any, to its stockholders. Therefore, no provision for federal income taxes is required. As of April 30, 2024, the Fund did not accrue any interest or penalties with respect to uncertain tax positions, which, if applicable, would be recorded as an income tax expense on the Statement of Operations. The tax return filed within the prior year remains subject to examination by federal and state tax authorities.
	The amount and character of income and capital gain distributions to stockholders are determined in accordance with federal income tax rules, which may differ from U.S. GAAP. Distributions in excess of net investment income or net realized gains are temporary over distributions

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2429

---

---

Table of Contents

	for financial statement purposes resulting from differences in the recognition or classification of income or distributions for financial statement and tax purposes. Capital accounts within the financial statements are adjusted for permanent book/tax differences to reflect tax character, but are not adjusted for temporary differences.
	At April 30, 2024, the Fund was permitted to carry forward indefinitely $88,824,129 of short-term losses and $32,166,141 of long-term losses.
	The tax character of distributions paid during the years ended April 30, 2024 and April 30, 2023, was as follows:

	2024	2023
Distributions paid from:
Tax-exempt income	$8,561,026	$8,626,200
Ordinary income	84,846	1,490
Tax return of capital	193,568	2,845,853
Total	$8,839,440	$11,473,543

The following shows the components of distributable earnings (losses) on a federal income tax basis at April 30, 2024:

	2024
Distributable earnings/(losses):
Capital loss carryforward	$(120,990,270)
Other book/tax temporary differences	(844,263)
Net unrealized depreciation	(161,285)
Total	$(121,995,818)

The difference between book-basis and tax-basis unrealized depreciation is primarily attributable to the tax adjustments related to wash sales and discounts on fixed income securities.

D.

Automatic Dividend Reinvestment Plan

All stockholders whose shares are registered in their own names automatically participate in the Automatic Dividend Reinvestment Plan (the “Plan”), under which participants receive all dividends and capital gain distributions (collectively, dividends) in full and fractional shares of the Fund in lieu of cash. Stockholders may elect not to participate in the Plan. Stockholders not participating in the Plan receive all dividends and capital gain distributions in cash. Participation in the Plan is completely voluntary and may be terminated or resumed at any time without penalty by notifying Equiniti Trust Company, the agent for stockholders in administering the Plan (the “Plan Agent”), in writing prior to any dividend record date; otherwise such termination or resumption will be effective with respect to any subsequently declared dividend or other distribution.

30Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

	If a stockholder’s shares are held in the name of a brokerage firm, bank or other nominee, the stockholders can ask the firm or nominee to participate in the Plan on the stockholder’s behalf. If the firm or nominee does not offer the Plan, dividends will be paid in cash to the stockholders of record. A firm or nominee may reinvest a stockholder’s cash dividends in shares of the Fund on terms that differ from the terms of the Plan.
	Whenever the Fund declares a dividend on shares payable in cash, participants in the Plan will receive the equivalent in shares acquired by the Plan Agent either (i) through receipt of additional unissued but authorized shares from the Fund or (ii) by purchase of outstanding hares on the New York Stock Exchange or elsewhere. If, on the payment date for any dividend, the net asset value per share is equal to or less than the market price per share plus estimated brokerage trading fees (market premium), the Plan Agent will invest the dividend amount in newly issued shares. The number of newly issued shares to be credited o each account will be determined by dividing the dollar amount of the dividend by the net asset value per share on the date the shares are issued, provided that the maximum discount from the then current market price per share on the date of issuance does not exceed 5%. If, on the payment date for any dividend, the net asset value per share is greater than the market value (market discount), the Plan Agent will invest the dividend amount in shares acquired in open-market purchases. There are no brokerage charges with respect to newly issued shares. However, each participant will pay a pro rata share of brokerage trading fees incurred with respect to the Plan Agent’s open-market purchases. Participating in the Plan does not relieve stockholders from any federal, state or local taxes which may be due on dividends paid in any taxable year. Stockholders holding Plan shares in a brokerage account may be able to transfer the shares to another broker and continue to participate in the Plan.
E.	Risks
	The value of securities held by the Fund may go up or down, sometimes rapidly or unpredictably, due to general market conditions, such as real or perceived adverse economic, political or regulatory conditions, recessions, the spread of infectious illness or other public health issues, inflation, changes in interest rates, armed conflict such as between Russia and Ukraine or in the Middle East, sanctions against Russia, other nations or individuals or companies and possible countermeasures, lack of liquidity in the bond markets or adverse investor sentiment. In the past several years, financial markets have experienced increased volatility, depressed valuations, decreased liquidity and heightened

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2431

---

---

Table of Contents

	uncertainty. These conditions may continue, recur, worsen or spread. Inflation and interest rates have increased and may rise further. These circumstances could adversely affect the value and liquidity of the Fund’s investments and negatively impact the Fund’s performance.
	The long-term impact of the COVID-19 pandemic and its subsequent variants on economies, markets, industries and individual issuers, are not known. Some sectors of the economy and individual issuers have experienced or may experience particularly large losses. Periods of extreme volatility in the financial markets, reduced liquidity of many instruments, increased government debt, inflation, and disruptions to supply chains, consumer demand and employee availability, may continue for some time. Following Russia’s invasion of Ukraine, Russian securities lost all, or nearly all, their market value. Other securities or markets could be similarly affected by past or future political, geopolitical or other events or conditions.
	Governments and central banks, including the U.S. Federal Reserve, have taken extraordinary and unprecedented actions to support local and global economies and the financial markets. These actions have resulted in significant expansion of public debt, including in the U.S. The consequences of high public debt, including its future impact on the economy and securities markets, may not be known for some time.
	The U.S. and other countries are periodically involved in disputes over trade and other matters, which may result in tariffs, investment restrictions and adverse impacts on affected companies and securities. For example, the U.S. has imposed tariffs and other trade barriers on Chinese exports, has restricted sales of certain categories of goods to China, and has established barriers to investments in China. Trade disputes may adversely affect the economies of the U.S. and its trading partners, as well as companies directly or indirectly affected and financial markets generally. If the political climate between the U.S. and China does not improve or continues to deteriorate, if China were to attempt unification of Taiwan by force, or if other geopolitical conflicts develop or get worse, economies, markets and individual securities may be severely affected both regionally and globally, and the value of the Fund’s assets may go down.
	At times, the Fund’s investments may represent industries or industry sectors that are interrelated or have common risks, making the Fund more susceptible to any economic, political, or regulatory developments or other risks affecting those industries and sectors.
	Under normal circumstances, the Fund will invest substantially all of its assets in municipal securities. The municipal bond market can be

32Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

	susceptible to unusual volatility, particularly for lower-rated and unrated securities. Liquidity can be reduced unpredictably in response to overall economic conditions or credit tightening. Municipal issuers may be adversely affected by rising health care costs, increasing unfunded pension liabilities, and by the phasing out of federal programs providing financial support. Unfavorable conditions and developments relating to projects financed with municipal securities can result in lower revenues to issuers of municipal securities, potentially resulting in defaults. Issuers often depend on revenues from these projects to make principal and interest payments. The value of municipal securities can also be adversely affected by changes in the financial condition of one or more individual municipal issuers or insurers of municipal issuers, regulatory and political developments, tax law changes or other legislative actions, and by uncertainties and public perceptions concerning these and other factors. Municipal securities may be more susceptible to down-grades or defaults during recessions or similar periods of economic stress. Financial difficulties of municipal issuers may continue or get worse. To the extent the Fund invests significantly in a single state (including New York and California), city, territory (including Puerto Rico), or region, or in securities the payments on which are dependent upon a single project or source of revenues, or that relate to a sector or industry, including tobacco settlement bond revenues, industrial development revenues, health care facilities, education, transportation, special revenues and pollution control, the Fund will be more susceptible to associated risks and developments.
	The Fund invests primarily in below investment grade (high yield) municipal securities. Debt securities, loans rated below investment grade are commonly referred to as “junk bonds” and are considered speculative with respect to the issuer's capacity to pay interest and repay principal. These securities involve greater risk of loss, are subject to greater price volatility, and may be less liquid and more difficult to value, especially during periods of economic uncertainty or change, than higher rated debt securities.
	The market prices of the Fund’s fixed income securities may fluctuate significantly when interest rates change. The value of your investment will generally go down when interest rates rise. A rise in rates tends to have a greater impact on the prices of longer term or duration securities. For example, if interest rates increase by 1%, the value of a Fund’s portfolio with a portfolio duration of ten years would be expected to decrease by 10%, all other things being equal. In recent years interest rates and credit spreads in the U.S. have been at historic lows. The U.S. Federal Reserve has raised certain interest rates, and interest rates

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2433

---

---

Table of Contents

	may continue to go up. A general rise in interest rates could adversely affect the price and liquidity of fixed income securities. The maturity of a security may be significantly longer than its effective duration. A security’s maturity and other features may be more relevant than its effective duration in determining the security’s sensitivity to other factors affecting the issuer or markets generally, such as changes in credit quality or in the yield premium that the market may establish for certain types of securities (sometimes called “credit spread”). In general, the longer its maturity the more a security may be susceptible to these factors. When the credit spread for a fixed income security goes up, or “widens”, the value of the security will generally go down.
	If an issuer or guarantor of a security held by the Fund or a counterparty to a financial contract with the Fund defaults on its obligation to pay principal and/or interest, has its credit rating downgraded or is perceived to be less creditworthy, or the credit quality or value of any underlying assets declines, the value of your investment will typically decline. Changes in actual or perceived creditworthiness may occur quickly. The Fund could be delayed or hindered in its enforcement of rights against an issuer, guarantor or counterparty.
	With the increased use of technologies such as the Internet to conduct business, the Fund is susceptible to operational, information security and related risks. While the Fund’s Adviser has established business continuity plans in the event of, and risk management systems to prevent, limit or mitigate, such cyber-attacks, there are inherent limitations in such plans and systems, including the possibility that certain risks have not been identified. Furthermore, the Fund cannot control the cybersecurity plans and systems put in place by service providers to the Fund such as the Fund’s custodian and accounting agent, and the Fund’s transfer agent. In addition, many beneficial owners of Fund shares hold them through accounts at broker-dealers, retirement platforms and other financial market participants over which neither the Fund nor the Adviser exercises control. Each of these may in turn rely on service providers to them, which are also subject to the risk of cyber-attacks. Cybersecurity failures or breaches at the Adviser or the Fund’s service providers or intermediaries have the ability to cause disruptions and impact business operations, potentially resulting in financial losses, interference with the Fund’s ability to calculate its net asset value, impediments to trading, the inability of Fund stockholders to effect share purchases or sales or receive distributions, loss of or unauthorized access to private stockholder information and violations of applicable privacy and other laws, regulatory fines, penalties, reputational damage, or additional compliance costs. Such costs and

34Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

	losses may not be covered under any insurance. In addition, maintaining vigilance against cyber-attacks may involve substantial costs over time, and system enhancements may themselves be subject to cyber-attacks.
F.	Statement of Cash Flows
	Information on financial transactions which have been settled through the receipt or disbursement of cash or restricted cash is presented in the Statement of Cash Flows. Cash as presented in the Fund’s Statement of Assets and Liabilities includes cash on hand at the Fund’s custodian bank and does not include any short-term investments. As of and for the year ended April 30, 2024, the Fund had restricted cash in the form of futures collateral on the Statement of Assets and Liabilities.
G.	Futures Contracts
	The Fund may enter into futures transactions in order to attempt to hedge against changes in interest rates, securities prices and currency exchange rates or to seek to increase total return. Futures contracts are types of derivatives.
	All futures contracts entered into by the Fund are traded on a futures exchange. Upon entering into a futures contract, the Fund is required to deposit with a broker an amount of cash or securities equal to the minimum “initial margin” requirements of the associated futures exchange. The amount of cash deposited with the broker as collateral at April 30, 2024 is recorded as “Futures collateral” on the Statement of Assets and Liabilities.
	Subsequent payments for futures contracts (“variation margin”) are paid or received by the Fund, depending on the daily fluctuation in the value of the contracts, and are recorded by the Fund as unrealized appreciation or depreciation. Cash received from or paid to the broker related to previous margin movement is held in a segregated account at the broker and is recorded as either “Due from broker for futures” or “Due to broker for futures” on the Statement of Assets and Liabilities. When the contract is closed, the Fund realizes a gain or loss equal to the difference between the opening and closing value of the contract as well as any fluctuation in foreign currency exchange rates where applicable. Futures contracts are subject to market risk, interest rate risk and currency exchange rate risk. Changes in value of the contracts may not directly correlate to the changes in value of the underlying securities. With futures, there is reduced counterparty credit risk to the Fund since futures are exchange-traded and the exchange’s clearinghouse, as counterparty to all exchange-traded futures, guarantees the futures against default.

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2435

---

---

Table of Contents

The average notional value of long position futures contracts during the year ended April 30, 2024 was $3,892,716. Open futures contracts outstanding at April 30, 2024 are listed in the Schedule of Investments.

2. Management Agreement

The Adviser manages the Fund’s portfolio. Management fees payable under the Fund’s Investment Management Agreement with the Adviser are calculated daily and paid monthly at the annual rate of 0.80% of the Fund’s average daily managed assets. “Managed assets” means (a) the total assets of the Fund, including any form of investment leverage, minus (b) all accrued liabilities incurred in the normal course of operations, which shall not include any liabilities or obligations attributable to investment leverage obtained through (i) indebtedness of any type (including, without limitation, borrowing through a credit facility or the issuance of debt securities), (ii) the issuance of preferred stock or other similar preference securities, and/or (iii) any other means. For the year ended April 30, 2024, the management fee (excluding waivers and/or assumption of expenses) was 0.80% of the Fund’s average daily managed assets, which was equivalent to 0.93% of the Fund’s average daily net assets.

In addition, under the management and administration agreements, certain other services and costs, including accounting, regulatory reporting and insurance premiums, are paid by the Fund as administrative reimbursements. Reflected on the Statement of Assets and Liabilities is $25,953 in management fees payable to the Adviser at April 30, 2024.

3. Compensation of Directors and Officers

The Fund pays an annual fee to its Directors. The Adviser reimburses the Fund for fees paid to the Interested Directors. Except for the chief compliance officer, the Fund does not pay any salary or other compensation to its officers. The Fund pays a portion of the chief compliance officer's compensation for his services as the Fund's chief compliance officer. Amundi US pays the remaining portion of the chief compliance officer's compensation. For the year ended April 30, 2024, the Fund paid $9,405 in Officers' and Directors’ compensation, which is reflected on the Statement of Operations as Officers' and Directors’ fees. At April 30, 2024, the Fund had a payable for Directors’ fees on its Statement of Assets and Liabilities of $765.

4. Transfer Agent

Equiniti Trust Company, LLC ("EQ"), formerly known as American Stock Transfer & Trust Company, serves as the transfer agent with respect to the Fund’s common shares. The Fund pays EQ an annual fee as is agreed to from time to time by the Fund and EQ for providing such services.

36Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

In addition, the Fund reimbursed the transfer agent for out-of-pocket expenses incurred by the transfer agent related to stockholder communications activities such as proxy and statement mailings and outgoing phone calls.

5. Additional Disclosures about Derivative Instruments and Hedging Activities

The Fund’s use of derivatives may enhance or mitigate the Fund’s exposure to the following risks:

Interest rate risk relates to the fluctuations in the value of interest-bearing securities due to changes in the prevailing levels of market interest rates.

Credit risk relates to the ability of the issuer of a financial instrument to make further principal or interest payments on an obligation or commitment that it has to the Fund.

Foreign exchange rate risk relates to fluctuations in the value of an asset or liability due to changes in currency exchange rates.

Equity risk relates to the fluctuations in the value of financial instruments as a result of changes in market prices (other than those arising from interest rate risk or foreign exchange rate risk), whether caused by factors specific to an individual investment, its issuer, or all factors affecting all instruments traded in a market or market segment.

Commodity risk relates to the risk that the value of a commodity or commodity index will fluctuate based on increases or decreases in the commodities market and factors specific to a particular industry or commodity.

The fair value of open derivative instruments (not considered to be hedging instruments for accounting disclosure purposes) by risk exposure at April 30, 2024, was as follows:

Statement of Assets and Liabilities	Interest Rate Risk	Credit Risk	Foreign Exchange Rate Risk	Equity Risk	Commodity Risk
Liabilities
Net unrealized depreciation on futures contracts	$298,760	$—	$—	$—	$—
Total Value	$298,760	$—	$—	$—	$—

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2437

---

---

Table of Contents

The effect of derivative instruments (not considered to be hedging instruments for accounting disclosure purposes) on the Statement of Operations by risk exposure at April 30, 2024 was as follows:

Statement of Operations	Interest Rate Risk	Credit Risk	Foreign Exchange Rate Risk	Equity Risk	Commodity Risk
Net Realized Gain (Loss) on
Futures contracts	$(463,521)	$—	$—	$—	$—
Total Value	$(463,521)	$—	$—	$—	$—
Change in Net Unrealized Appreciation (Depreciation) on
Futures contracts	$(298,760)	$—	$—	$—	$—
Total Value	$(298,760)	$—	$—	$—	$—

6. Fund Shares

There are 1,000,000,000 shares of common stock of the Fund (“common shares”), $0.001 par value per share authorized. Transactions in common shares for the year ended April 30, 2024 and April 30, 2023 were as follows:

	4/30/24	4/30/23
Shares outstanding at beginning of year	16,885,273	16,885,273
Shares outstanding at end of year	16,885,273	16,885,273

7. Credit Agreement

The Fund has entered into a credit facility (the "Credit Agreement") with The Bank of New York Mellon. There is a $75,000,000 borrowing limit under the Credit Agreement. The outstanding loans under the Credit Agreement bear interest at a rate equal to the Overnight Bank Funding Rate plus 0.95% per annum.

At April 30, 2024, the Fund had a borrowing outstanding under the credit agreement totaling $26,000,000. The interest rate charged at April 30, 2024 was 6.27%. During the year ended April 30, 2024, the average daily balance under the Credit Agreement was $33,754,098 at an average interest rate of 6.07%. Interest expense of $2,084,065 in connection with the Credit Agreement is included on the Statement of Operations.

Borrowings under the Credit Agreement are subject to certain limitations, including (a) that the outstanding amount of the loans under the Credit Agreement cannot exceed the lesser of (i) $75,000,000 and (ii) the sum of the collateral value of all “Eligible Securities” (which consist of nondistressed U.S. municipal bonds, with certain concentration limits) over which The Bank of New York Mellon has a first lien, divided by the “Margin” (which ranges from 120% to 200% depending on the rating of the

38Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

Eligible Security) and (b) any limitations imposed by applicable law, including the Investment Company Act of 1940, as amended.

The Credit Agreement renews on a daily basis in perpetuity. The Bank of New York Mellon may, at any time, deliver to the Fund a termination notice, which becomes effective 180 days after its receipt by the Fund.

8. Subsequent Events

A monthly distribution was declared on May 3, 2024 of $0.0500 per common share payable May 31, 2024, to common stockholders of record on May 17, 2024.

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2439

---

---

Table of Contents

Report of Independent Registered Public Accounting Firm

To the Board of Directors and the Stockholders of Pioneer Municipal High Income Opportunities Fund, Inc.:

---

Opinion on the Financial Statements and Financial Highlights

We have audited the accompanying statement of assets and liabilities of Pioneer Municipal High Income Opportunities Fund, Inc. (the “Fund”), including the schedule of investments, as of April 30, 2024, the related statements of operations, changes in net assets, cash flows and the financial highlights for the year then ended and the related notes. The statements of changes in net assets for the year ended April 30, 2023 and the financial highlights for the year ended April 30, 2023 and the period from August 6, 2021 (commencement of operations) through April 30, 2022 were audited by other auditors. Those auditors expressed an unqualified opinion on those financial statements and financial highlights in their report dated June 27, 2023. In our opinion, the financial statements and financial highlights present fairly, in all material respects, the financial position of the Fund as of April 30, 2024 and the results of its operations, cash flows, the changes in its net assets, and the financial highlights for the year then ended, in conformity with accounting principles generally accepted in the United States of America.

Basis for Opinion

These financial statements and financial highlights are the responsibility of the Fund's management. Our responsibility is to express an opinion on the Fund's financial statements and financial highlights based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Fund in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements and financial highlights are free of material misstatement, whether due to error or fraud. The Fund is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the

40Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

effectiveness of the Fund’s internal control over financial reporting. Accordingly, we express no such opinion.

Our audits included performing procedures to assess the risks of material misstatement of the financial statements and financial highlights, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements and financial highlights. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements and financial highlights. Our procedures included confirmation of securities owned as of April 30, 2024, by correspondence with the custodian and brokers; when replies were not received from brokers, we performed other auditing procedures. We believe that our audits provide a reasonable basis for our opinion.

DELOITTE & TOUCHE LLP

Boston, Massachusetts
June 27, 2024

We have served as the auditor of one or more of the Pioneer investment companies since 2024.

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2441

---

---

Table of Contents

Additional Information (unaudited)

On March 25, 2024, Ernst & Young LLP (the “Prior Auditor”) resigned as the independent registered public accounting firm of Pioneer Municipal High Income Opportunities Fund, Inc. (the “Fund”) due to the independence considerations resulting from a change of the independent registered public accounting firm of a related party. The Prior Auditor’s reports on the financial statements of the Fund for the past two fiscal years, the years ended April 30, 2023 and April 30, 2022, did not contain an adverse opinion or disclaimer of opinion, and were not qualified or modified as to uncertainty, audit scope or accounting principles.

During the last two fiscal year-ends and the subsequent interim period through March 25, 2024, there were no (1) disagreements with the Prior Auditor on any matter of accounting principles or practices, financial statement disclosure, or auditing scope or procedure, which disagreements, if not resolved to the Prior Auditor’s satisfaction, would have caused it to make reference to that matter in connection with its reports on the Fund’s financial statements for such periods; or (2) “reportable events” related to the Fund,  as that term is defined in Item 304 (a)(1)(v) of Regulation S-K under the Securities Exchange Act of 1934.

On March 25, 2024, the Audit Committee of the Board approved, and on March 25, 2024, the Board approved, Deloitte & Touche LLP as the independent registered accounting firm of the Fund for fiscal periods ending after March 25, 2024.

Notice is hereby given in accordance with Section 23(c) of the Investment Company Act of 1940 that the Fund may purchase, from time to time, its shares in the open market.

Qualified interest income is exempt from nonresident alien (NRA) tax withholding. The percentage of the Fund’s ordinary income distributions derived from qualified interest income was 100.00%.

Anti-takeover provisions. The Fund’s Charter and Bylaws include provisions that are designed to limit the ability of other entities or persons to acquire control of the Fund for short-term objectives, including by converting the Fund to open-end status or changing the composition of the Board, that may be detrimental to the Fund's ability to achieve its primary investment objective of seeking to provide its common stockholders with a high level of current income exempt from regular federal income tax. These provisions include staggered terms of service for the Directors, advance notice requirements for stockholder proposals, and super-majority voting requirements for certain transactions with affiliates, open-ending the Fund or a merger, liquidation, asset sale or similar transaction. The Fund’s

42Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

Bylaws also contain a provision providing that the Board of Directors has adopted a resolution to opt in the Fund to the provisions of the Maryland Control Share Acquisition Act (“MCSAA”). Such provisions may limit the ability of stockholders to sell their shares at a premium over prevailing market prices by discouraging a third party from seeking to obtain control of the Fund. There can be no assurance, however, that such provisions will be sufficient to deter activist investors that seek to cause the Fund to take actions that may not be aligned with the interests of long-term stockholders. Furthermore, the law is uncertain on the use of control share provisions. Certain courts have found that control share provisions are unenforceable under the 1940 Act. It is possible that a court could decide that the Fund’s decision to opt in to the MCSAA is not enforceable under the 1940 Act.

Exclusive forum provisions. The Fund’s Bylaws designate the Circuit Court for Baltimore City, Maryland as the sole and exclusive forum for certain types of actions and proceedings that may be initiated by the Fund’s stockholders and provide that claims relating to causes of action under the United States federal securities laws may only be brought in the United States District Court for the District of Maryland, Northern Division,which could limit stockholders’ ability to obtain a favorable judicial forum for disputes with the Fund or its directors, officers or the Fund’s agents, if any, and could discourage lawsuits against the Fund and its directors,officers and agents, if any.

The Fund’s Bylaws provide that, unless the Fund consents in writing to the selection of an alternative forum, the Circuit Court for Baltimore City,Maryland, or, if that court does not have jurisdiction, the United States District Court for the District of Maryland, Northern Division, will be the sole and exclusive forum for (a) any Internal Corporate Claim, as such term is defined in the MGCL, (b) any derivative action or proceeding brought on the Fund’s behalf (other than actions arising under federal securities laws),(c) any action asserting a claim of breach of any duty owed by any of the Fund’s directors, officers or other agents to the Fund or to the Fund’s stockholders, (d) any action asserting a claim against the Fund or any of the Fund’s directors, officers or other agents arising pursuant to any provision of the MGCL or the Fund’s Charter or Bylaws or (e) any other action asserting a claim against the Fund or any of the Fund’s directors,officers or other agents that is governed by the internal affairs doctrine. Furthermore, the Fund’s Bylaws provide that, unless the Fund consents in writing to the selection of an alternative forum, the United States District Court for the District of Maryland, Northern Division

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2443

---

---

Table of Contents

shall, to the fullest extent permitted by law, be the sole and exclusive forum for the resolution of any claim arising under the United States federal securities laws.

These exclusive forum provisions may limit the ability of the Fund’s stockholders to bring a claim in a judicial forum that such stockholders find favorable for disputes with the Fund or the Fund’s directors, officers, or agents, if any, which may discourage such lawsuits against the Fund and the Fund’s directors, officers, and agents, if any. Alternatively, if a court were to find the choice of forum provisions contained in the Fund’s Bylaws to be inapplicable or unenforceable in an action, the Fund may incur additional costs associated with resolving such action in other jurisdictions,which could materially adversely affect the Fund’s business, financial condition, and operating results.

44Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

Investment Objectives, Principal Investment Strategies and Principal Risks (unaudited)

CHANGES OCCURRING DURING THE MOST RECENT FISCAL YEAR

During the Fund’s most recent fiscal year, there were no material changes to the Fund’s investment objectives or policies that have not been approved by stockholders or in the principal risk factors associated with investment in the Fund.

INVESTMENT OBJECTIVES

The Fund’s primary investment objective is to provide its common stockholders with a high level of current income exempt from regular federal income tax. As a secondary investment objective, the Fund may seek capital appreciation to the extent consistent with its primary investment objective. Distributions from sources other than interest income from the Fund’s portfolio of municipal securities, including capital gain distributions, are not exempt from regular federal income tax. There can be no assurance that the Fund will achieve its investment objectives.

The Fund’s investment objectives may be changed without stockholder approval. The Fund will provide notice prior to implementing any change to its investment objectives.

PRINCIPAL INVESTMENT STRATEGIES

Normally, the Fund invests at least 80% of its net assets (plus the amount of borrowings, if any, for investment purposes) in securities issued by or on behalf of states, counties, municipalities, territories and possessions of the United States and the District of Columbia and their authorities, political subdivisions, agencies and instrumentalities, the interest on which is exempt from regular federal income tax (“municipal securities”). Derivative instruments that provide exposure to municipal securities or have similar economic characteristics may be used to satisfy the Fund’s 80% policy.

The Fund may invest without limit in debt securities of any credit quality, including those rated below investment grade (known as “high yield” or “junk” bonds) or, if unrated, of equivalent credit quality as determined by the Adviser. The Adviser expects that the Fund will invest mainly in securities that are below investment grade. Debt securities rated below investment grade are speculative, tend to be less liquid and are more difficult to value than higher grade securities. The Fund’s investments in securities rated below investment grade may include securities that are in default. The Fund may invest in debt securities, loans or preferred stock rated below investment grade or, if unrated, of equivalent credit quality as

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2445

---

---

Table of Contents

determined by the Adviser. Such investments may include credit obligations and related instruments of issuers that are insolvent or of issuers that either are in default or are likely to default.

Municipal securities are generally issued to finance public works such as housing, hospitals, schools, mass transportation projects, airports, bridges, highways, and water and sewer works. Municipal securities may be issued to repay outstanding obligations, to raise funds for general operating expenses, or to make loans to other institutions and facilities. They also may be issued by or on behalf of public authorities to finance various privately operated facilities which are expected to benefit the municipality and its residents, such as business, manufacturing, housing, sports and pollution control, as well as public facilities such as airports, mass transit systems, ports and parking. Municipal security issuances may be small, with the securities issued to one or a small number of institutional investors such as the Fund.

The Adviser considers both broad economic factors and issuer specific factors in selecting a portfolio designed to achieve the Fund’s investment objectives. In assessing the appropriate maturity and rating weighting of the Fund’s portfolio, the Adviser considers a variety of factors that are expected to influence economic activity and interest rates, as well as other economic fundamentals at national, state and regional levels. These factors include fundamental economic indicators, such as the rates of economic growth and inflation, Federal Reserve monetary policy and the relative value of the U.S. dollar compared to other currencies. Once the Adviser determines the preferable portfolio characteristics, the Adviser selects individual securities based upon the terms of the securities (such as yields compared to U.S. Treasuries or comparable issues), liquidity, rating, diversification and perceived risk. The Adviser also employs fundamental research, an evaluation of the obligor based on its financial statements and operations, to assess an obligor’s credit quality, taking into account financial condition, future capital needs and potential for change in rating. In making these portfolio decisions, the Adviser relies on the knowledge, experience and judgment of its staff and the staff of its affiliates who have access to a wide variety of research.

In selecting securities to buy and sell, the Adviser considers a security’s income and return prospects relative to perceived risk. In making decisions with respect to specific municipal securities, the Adviser employs a disciplined approach, driven primarily by in-depth credit research conducted by the Adviser’s investment staff. The Adviser attempts to identify municipal securities available at attractive valuations relative to the Adviser’s evaluation of the obligor’s creditworthiness and, with respect to private activity bonds, expectations of the revenue supporting the

46Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

bonds. The Adviser assesses a security’s income, return and risk characteristics as well as a security’s impact on the overall income, return and risk characteristics of the Fund. In making this assessment, the Adviser takes into account various factors including the credit quality, maturity, sensitivity to interest rates and the expected after-tax income of the security under consideration and of the Fund’s other holdings.

The Adviser anticipates investment opportunities in municipal securities funding projects that involve traditional infrastructure (e.g., bridges, highways, mass transit, and water and sewer), as well as projects that involve social infrastructure. Social infrastructure is broadly defined by the Adviser as the development, construction, improvement or maintenance of facilities that support social services or are intended to improve the quality of life of a community. Types of social infrastructure include education (such as charter schools, other educational facilities and programs, and expansion of internet access), health care (such as hospitals and other medical or dental services), retirement living (such as continuing care retirement facilities and other communities for older adults), and affordable housing, as well as projects with environmental purposes (such as waste disposal and the reduction of pollution or resource use).

The extent to which the Fund invests in specific market segments and project types will depend on the availability of such securities and their income, return and risk characteristics relative to those of other holdings, as well as other portfolio management considerations including diversification and overall credit and interest rate risk.

The Fund’s 80% investment policy may not be changed without stockholder approval. The Fund’s other investment strategies and policies may be changed from time to time without stockholder approval, unless specifically stated otherwise.

Portfolio investments. The Fund may invest in a broad range of issuers and segments of the municipal debt securities market. Municipal securities include general obligation bonds, revenue bonds, tax and revenue anticipation notes, bond anticipation notes, tax-exempt commercial paper, municipal leases, participation certificates and custodial receipts. General obligation bonds are backed by the full faith and credit of the issuing entity. Revenue bonds are typically used to fund particular projects, such as those relating to education, health care, transportation and utilities, that are expected to produce income sufficient to make the payments on the bonds, since they are not backed by the full taxing power of the municipality. Housing authority bonds are used primarily to fund low to middle income residential projects and may be backed by the payments made on the underlying mortgages. Tax and revenue anticipation notes are

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2447

---

---

Table of Contents

generally issued in order to finance short-term cash needs or, occasionally, to finance construction. Tax and revenue anticipation notes are expected to be repaid from taxes or designated revenues in the related period, and they may or may not be general obligations of the issuing entity. Bond anticipation notes are issued with the expectation that their principal and interest will be paid out of proceeds from renewal notes or bonds and may be issued to finance such items as land acquisition, facility acquisition and/or construction and capital improvement projects.

Municipal securities include municipal lease obligations, which are undivided interests issued by a state or municipality in a lease or installment purchase contract which generally relates to equipment or facilities. In some cases, payments under municipal leases do not have to be made unless money is specifically approved for that purpose by an appropriate legislative body.

Although municipal securities are issued by qualifying issuers, payments of principal and interest on municipal securities may be derived solely from revenues from certain facilities, mortgages or private industries, and may not be backed by the issuers themselves. These securities include participation or other interests in municipal securities issued or backed by banks, insurance companies and other financial institutions.

The Fund purchases municipal securities the interest on which, in the opinion of bond counsel at the time the securities are issued, is exempt from regular federal income tax. There is no guarantee that this opinion is correct, and there is no assurance that the IRS will agree with bond counsel’s opinion. If the IRS determines that an issuer of a municipal security has not complied with applicable requirements, interest from the security could become subject to regular federal income tax, possibly retroactively to the date the security was issued, and the value of the security could decline significantly and a portion of the distributions to Fund stockholders could be recharacterized as taxable. Future litigation or legislation could adversely affect the tax treatment of municipal securities held by the Fund.

The Fund may invest in municipal securities of any maturity. Municipal securities with longer maturities are generally more volatile than other fixed income securities with shorter maturities. The Fund may invest 25% or more of its assets in issuers in any one or more states or in the same economic sector or similar project type (such as projects relating to health care, education, transportation, and utilities).

The Fund may invest without limit in debt securities of any credit quality, including “high yield” municipal obligations. For this purpose, “high yield” municipal obligations are municipal obligations rated at the time of

48Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

purchase Ba or lower by Moody’s or BB or lower by S&P or unrated securities determined by the Adviser to be of comparable credit quality. The Adviser expects that the Fund will invest mainly in securities that are below investment grade. Municipal securities of below investment grade quality are regarded as having predominantly speculative characteristics with respect to the issuer’s capacity to pay interest and repay principal, and are commonly referred to as “junk bonds.” The Fund may invest in securities in any rating category, including those in default, and in debtor-in-possession financings. The Fund may invest in debt securities, loans or preferred stock rated below investment grade or, if unrated, of equivalent credit quality as determined by the Adviser. Such investments may include credit obligations and related instruments of issuers that are insolvent or of issuers that either are in default or are likely to default.

Interest income from certain types of municipal securities in which the Fund may invest generally may be subject to the federal alternative minimum tax (the “AMT”). The Fund may not be suitable for investors subject to the AMT. The rate of interest paid on municipal securities normally is lower than the rate of interest paid on taxable securities.

The Fund’s investments may have fixed or variable principal payments and all types of interest rate payment and reset terms, including fixed and floating rates, inverse floating rate, zero coupon, contingent, deferred and payment in kind and auction rate features.

The Fund also may invest in subordinated securities, asset-backed securities of any rating, and may hold cash or other short-term investments. A holder of securities that are subordinated or “junior” to more senior securities of an issuer is entitled to payment after the holders of more senior securities of the issuer. The Fund’s investments may include mortgage-backed instruments, the underlying assets of which allow for balloon payments (where a substantial portion of a mortgage loan balance is paid at maturity, which can shorten the average life of the mortgage-backed instrument) or negative amortization payments (where, as a result of a payment cap, payments on a mortgage loan are less than the amount of principal and interest owed, with excess amounts added to the outstanding principal balance, which can extend the average life of the mortgage-backed instrument).

The Fund may invest up to 20% of its net assets in taxable investments, including securities of other investment companies (including mutual funds, exchange-traded funds and closed-end funds), commercial paper, U.S. government securities, U.S. or foreign bank instruments and repurchase agreements.

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2449

---

---

Table of Contents

The Fund may invest in securities and instruments that are not income-producing for purposes of seeking capital appreciation or managing risk or other portfolio characteristics.

Municipal securities. Municipal securities are often issued to obtain funds for various public purposes, including refunding outstanding obligations, funding for general operating expenses and lending to other public institutions and facilities. Municipal securities also include certain “private activity bonds” or industrial development bonds, which are issued by or on behalf of public authorities to provide financing aid to acquire sites or construct or equip facilities within a municipality for privately or publicly owned corporations. The two principal classifications of municipal securities are “general obligations” and “revenue obligations.” General obligations are secured by the issuer’s pledge of its full faith and credit for the payment of principal and interest, although the characteristics and enforcement of general obligations may vary according to the law applicable to the particular issuer. Revenue obligations, which include, but are not limited to, private activity bonds, certificates of participation and certain municipal notes, are not backed by the credit and taxing authority of the issuer and are payable solely from the revenues derived from a particular facility or class of facilities or, in some cases, from the proceeds of a special excise or other specific revenue source. The obligations of the issuer of a revenue obligation may, in addition, be backed by a letter of credit from a bank, a guarantee from another issuer or insurance. The credit rating assigned to municipal securities may reflect the existence of these guarantees, letters of credit or other credit enhancement features. General obligations and revenue obligations may be issued in a variety of forms, including commercial paper, fixed, variable and floating rate securities, tender option bonds, auction rate bonds, zero coupon bonds, deferred interest bonds and capital appreciation bonds. In addition to general obligations and revenue obligations, there are a variety of hybrid and special types of municipal securities.

One or a small number of institutional investors such as the Fund may purchase an entire issue of municipal securities. Thus, the issue may not be said to be publicly offered. Unlike some securities that are not publicly offered, a secondary market exists for many municipal securities that were not publicly offered initially and such securities may be readily marketable.

Although distributions of interest income from the Fund’s municipal securities are generally exempt from regular federal income tax, distributions from other sources, including capital gain distributions, and any gains on the sale of your common shares are not. You should consult

50Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

your tax adviser as to whether the AMT applies to you and as to whether you will be subject to state and local taxes on your distributions from the Fund.

From time to time, proposals have been introduced before Congress for the purpose of restricting or eliminating the federal income tax exemption for interest on municipal securities. The Fund cannot predict what legislation, if any, may be proposed in the future in Congress regarding the federal income tax status of interest on municipal securities. Such proposals, if enacted, might materially and adversely affect the Fund.

The Fund may invest in municipal securities that are collateralized by the proceeds from class action or other litigation against the tobacco industry. Payment by tobacco industry participants of such proceeds is spread over several years, and the collection and distribution of such proceeds to the issuers of municipal securities is dependent upon the financial health of such tobacco industry participants, which cannot be assured. Additional litigation, government regulation or prohibition on the sales of tobacco products, or the seeking of protection under the bankruptcy laws, could adversely affect the tobacco industry, which, in turn, could have an adverse affect on tobacco-related municipal securities.

Municipal leases and certificates of participation. The Fund may invest in municipal leases and certificates of participation in such leases. A municipal lease is an obligation in the form of a lease or installment purchase that is issued by a state or local government to acquire equipment and facilities. Income from such obligations is generally exempt from state and local taxes in the state of issuance. Municipal leases frequently involve special risks not normally associated with general obligations or revenue obligations. Leases and installment purchase or conditional sale contracts (which normally provide for title to the leased asset to pass eventually to the governmental issuer) have evolved as a means for governmental issuers to acquire property and equipment without meeting the constitutional and statutory requirements for the issuance of debt. The debt issuance limitations are deemed to be inapplicable because of the inclusion in many leases or contracts of “non-appropriation” clauses that relieve the governmental issuer of any obligation to make future payments under the lease or contract unless money is appropriated for such purpose by the appropriate legislative body on a yearly or other periodic basis. In addition, such leases or contracts may be subject to the temporary abatement of payments in the event the issuer is prevented from maintaining occupancy of the leased premises or utilizing the leased equipment. Although the obligations may be secured by the leased equipment or facilities, the disposition of the property in the event of non-appropriation or foreclosure might prove difficult, time consuming and costly, and result in a delay in

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2451

---

---

Table of Contents

recovering, or the failure to fully recover, the Fund’s original investment. To the extent that the Fund invests in unrated municipal leases or participates in such leases, the credit quality and risk of cancellation of such unrated leases will be monitored on an ongoing basis.

A certificate of participation represents an undivided interest in an unmanaged pool of municipal leases, installment purchase agreements or other instruments. The certificates are typically issued by a municipal agency, a trust or other entity that has received an assignment of the payments to be made by the state or political subdivision under such leases or installment purchase agreements. Such certificates provide the Fund with the right to a pro rata undivided interest in the underlying municipal securities. In addition, such participations generally provide the Fund with the right to demand payment, on not more than seven days’ notice, of all or any part of the Fund’s participation interest in the underlying municipal securities, plus accrued interest.

Certain municipal lease obligations and certificates of participation may be deemed to be illiquid. Other municipal lease obligations and certificates of participation acquired by the Fund may be determined by the Adviser, pursuant to guidelines adopted by the Board, to be liquid securities. In determining the liquidity of municipal lease obligations and certificates of participation, the Adviser will consider a variety of factors, including: (i) the willingness of dealers to bid for the obligation; (ii) the number of dealers willing to purchase or sell the obligation and the number of other potential buyers; (iii) the frequency of trades or quotes for the obligation; and (iv) the nature of the marketplace trades. In addition, the Adviser will consider factors unique to particular lease obligations and certificates of participation affecting the marketability thereof. These include the general creditworthiness of the issuer, the importance to the issuer of the property covered by the lease and the likelihood that the marketability of the obligation will be maintained throughout the time the obligation is held by the Fund.

Municipal notes. Municipal securities in the form of notes generally are used to provide for short-term capital needs, in anticipation of an issuer’s receipt of other revenues or financing, and typically have maturities of up to three years. Such instruments may include tax anticipation notes, revenue anticipation notes, bond anticipation notes, tax and revenue anticipation notes and construction loan notes. Tax anticipation notes are issued to finance the working capital needs of governments. Generally, they are issued in anticipation of various tax revenues, such as income, sales, property, use and business taxes, and are payable from these specific future taxes. Revenue anticipation notes are issued in expectation of receipt of other kinds of revenue, such as federal revenues available under

52Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

federal revenue sharing programs. Bond anticipation notes are issued to provide interim financing until long-term bond financing can be arranged. In most cases, the long-term bonds then provide the funds needed for repayment of the notes. Tax and revenue anticipation notes combine the funding sources of both tax anticipation notes and revenue anticipation notes. Construction loan notes are sold to provide construction financing. Mortgage notes insured by the Federal Housing Authority secure these notes; however, the proceeds from the insurance may be less than the economic equivalent of the payment of principal and interest on the mortgage note if there has been a default. The anticipated revenues from taxes, grants or bond financing generally secure the obligations of an issuer of municipal notes. An investment in such instruments, however, presents a risk that the anticipated revenues will not be received or that such revenues will be insufficient to satisfy the issuer’s payment obligations under the notes or that refinancing will be otherwise unavailable.

Tax-exempt commercial paper. Issues of commercial paper typically represent short-term, unsecured, negotiable promissory notes. These obligations are issued by state and local governments and their agencies to finance the working capital needs of municipalities or to provide interim construction financing and are paid from general revenues of municipalities or are refinanced with long-term debt. In most cases, tax-exempt commercial paper is backed by letters of credit, lending agreements, note repurchase agreements or other credit facility agreements offered by banks or other institutions.

Pre-refunded municipal securities. The principal of and interest on pre-refunded municipal securities are no longer paid from the original revenue source for the securities. Instead, the source of such payments is typically an escrow fund consisting of U.S. government securities. The assets in the escrow fund are derived from the proceeds of refunding bonds issued by the same issuer as the pre-refunded municipal securities. Issuers of municipal securities use this advance refunding technique to obtain more favorable terms with respect to securities that are not yet subject to call or redemption by the issuer. For example, advance refunding enables an issuer to refinance debt at lower market interest rates, restructure debt to improve cash flow or eliminate restrictive covenants in the indenture or other governing instrument for the pre-refunded municipal securities. However, except for a change in the revenue source from which principal and interest payments are made, the pre-refunded municipal securities remain outstanding on their original terms until they mature or are redeemed by the issuer.

Private activity bonds. Private activity bonds, formerly referred to as industrial development bonds, are issued by or on behalf of public

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2453

---

---

Table of Contents

authorities to obtain funds to provide privately operated housing facilities, airport, mass transit or port facilities, sewage disposal, solid waste disposal or hazardous waste treatment or disposal facilities and certain local facilities for water supply, gas or electricity. Other types of private activity bonds, the proceeds of which are used for the construction, equipment, repair or improvement of privately operated industrial or commercial facilities, may constitute municipal securities, although the current federal tax laws place substantial limitations on the size of such issues. The Fund’s distributions of its interest income from private activity bonds may subject certain investors to the AMT.

Tender option bonds. A tender option bond is a municipal security (generally held pursuant to a custodial arrangement) having a relatively long maturity and bearing interest at a fixed rate substantially higher than prevailing short-term, tax-exempt rates. The bond is typically issued with the agreement of a third party, such as a bank, broker-dealer or other financial institution, which grants the security holders the option, at periodic intervals, to tender their securities to the institution and receive the face value thereof. As consideration for providing the option, the financial institution receives periodic fees equal to the difference between the bond’s fixed coupon rate and the rate, as determined by a remarketing or similar agent at or near the commencement of such period, that would cause the securities, coupled with the tender option, to trade at par on the date of such determination. Thus, after payment of this fee, the security holder effectively holds a demand obligation that bears interest at the prevailing short-term, tax-exempt rate. However, an institution will not be obligated to accept tendered bonds in the event of certain defaults or a significant downgrade in the credit rating assigned to the issuer of the bond. The liquidity of a tender option bond is a function of the credit quality of both the bond issuer and the financial institution providing liquidity. Tender option bonds are deemed to be liquid unless, in the opinion of the Adviser, the credit quality of the bond issuer and the financial institution is deemed, in light of the Fund’s credit quality requirements, to be inadequate and the bond would not otherwise be readily marketable. The Fund intends to invest in tender option bonds the interest on which will, in the opinion of bond counsel, counsel for the issuer of interests therein or counsel selected by the Adviser, be exempt from regular federal income tax. However, because there can be no assurance that the IRS will agree with such counsel’s opinion in any particular case, there is a risk that the Fund will not be considered the owner of such tender option bonds and thus will not be entitled to treat such interest as exempt from such tax. Additionally, the federal income tax treatment of certain other aspects of these investments, including the proper tax treatment of tender option bonds and the associated fees in relation to various regulated investment

54Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

company tax provisions, is unclear. The Fund intends to manage its portfolio in a manner designed to eliminate or minimize any adverse impact from the tax rules applicable to these investments.

Auction rate securities. The Fund may invest in auction rate securities. Auction rate securities include auction rate municipal securities and auction rate preferred securities issued by closed-end investment companies that invest primarily in municipal securities (collectively, “auction rate securities”). Provided that the auction mechanism is successful, auction rate securities usually permit the holder to sell the securities in an auction at par value at specified intervals. The dividend is reset by a “Dutch” auction in which bids are made by broker-dealers and other institutions for a certain amount of securities at a specified minimum yield. The dividend rate set by the auction is the lowest interest or dividend rate that covers all securities offered for sale. While this process is designed to permit auction rate securities to be traded at a value equal to the liquidation preference, there is some risk that an auction will fail due to insufficient demand for the securities. The Fund will take the time remaining until the next scheduled auction date into account for the purpose of determining the securities’ duration. The Fund’s investments in auction rate securities of closed-end funds are subject to the limitations prescribed by the 1940 Act.

Illiquid securities. The Fund may invest in bonds or other municipal securities that lack a secondary trading market or are otherwise considered illiquid. Liquidity of a security relates to the ability easily to dispose of the security and the price to be obtained upon disposition of the security, which may be less than would be obtained for a comparable, more liquid security. The Fund may invest without limit in illiquid investments due to the closed-end fund structure. Such investments may affect the Fund’s ability to realize its net asset value in the event of a voluntary or involuntary liquidation of its assets.

Structured securities. The Fund may invest in structured securities. The value of the principal and/or interest on such securities is determined by reference to changes in the value of specific currencies, interest rates, commodities, indices or other financial indicators (“reference”) or the relative change in two or more references. The interest rate or the principal amount payable upon maturity or redemption may be increased or decreased depending upon changes in the reference. The terms of the structured securities may provide, in certain circumstances, that no principal is due at maturity and, therefore, may result in a loss of the Fund’s investment. Changes in the interest rate or principal payable at maturity may be a multiple of the changes in the value of the reference. Consequently, structured securities may entail a greater degree of market risk than other types of fixed income securities.

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2455

---

---

Table of Contents

Insured municipal securities. The Fund may invest in “insured” municipal securities, which are securities for which scheduled payments of interest and principal are guaranteed by a private (non-governmental) insurance company. The insurance only entitles the Fund to receive at maturity the face or par value of the securities held by the Fund. The insurance does not guarantee the market value of the municipal securities or the value of the shares of the Fund. The Fund may utilize new issue or secondary market insurance. A bond issuer who wishes to increase the credit rating of a security purchases a new issue insurance policy. By paying a premium and meeting the insurer’s underwriting standards, the bond issuer is able to obtain a high credit rating (usually, Aaa from Moody’s or AAA from S&P) for the issued security. Such insurance is likely to increase the purchase price and resale value of the security. New issue insurance policies are non-cancelable and continue in force as long as the bonds are outstanding. A secondary market insurance policy is purchased by an investor subsequent to a bond’s original issuance and generally insures a particular bond for the remainder of its term.

Standby commitments. In order to enhance the liquidity of municipal securities, the Fund may acquire the right to sell a security to another party at a guaranteed price and date. Such a right to resell may be referred to as a “standby commitment” or “liquidity put,” depending on its characteristics. The aggregate price which the Fund pays for securities with standby commitments may be higher than the price which otherwise would be paid for the securities. Standby commitments may not be available or may not be available on satisfactory terms. Standby commitments may involve letters of credit issued by domestic or foreign banks supporting the other party’s ability to purchase the security. The right to sell may be exercisable on demand or at specified intervals and may form part of a security or be acquired separately by the Fund.

Because the period prior to the put date is generally less than 365 days, the Fund generally values the municipal securities subject to standby commitments at amortized cost. The Board has adopted procedures pursuant to which the Adviser may determine that amortized cost represents the fair value of these securities. The exercise price of the standby commitments is expected to approximate such amortized cost. Consequently, no separate value is assigned to standby commitments for purposes of determining the Fund’s net asset value. The cost of a standby commitment is carried as unrealized depreciation from the time of purchase until it is exercised or expires. Since the value of a standby commitment is dependent on the ability of the standby commitment writer to meet its obligation to repurchase, the Fund’s policy is to enter into standby commitment transactions only with banks, brokers or dealers that present a

56Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

minimal risk of default. However, this policy reduces, but does not eliminate, the risk of default by the standby commitment writer.

U.S. government securities. The Fund may invest in U.S. government securities. U.S. government securities are obligations of, or guaranteed by, the U.S. government, its agencies or government-sponsored entities. U.S. government securities include obligations: directly issued by or supported by the full faith and credit of the U.S. government, like Treasury bills, notes and bonds and Government National Mortgage Association (GNMA) certificates; supported by the right of the issuer to borrow from the U.S. Treasury, like those of the Federal Home Loan Banks (FHLBs); supported by the discretionary authority of the U.S. government to purchase the agency’s securities like those of the Federal National Mortgage Association (FNMA); or supported only by the credit of the issuer itself, like the Tennessee Valley Authority. U.S. government securities include issues by non-governmental entities (like financial institutions) that carry direct guarantees from U.S. government agencies as part of government initiatives in response to the market crisis or otherwise. U.S. government securities include zero coupon securities that make payments of interest and principal only upon maturity and which therefore tend to be subject to greater volatility than interest-bearing securities with comparable maturities. Although the U.S. government guarantees principal and interest payments on securities issued by the U.S. government and some of its agencies, such as securities issued by the GNMA, this guarantee does not apply to losses resulting from declines in the market value of these securities. Some of the U.S. government securities that the Fund may hold are not guaranteed or backed by the full faith and credit of the U.S. government, such as those issued by FNMA and the Federal Home Loan Mortgage Corporation (FHLMC).

Debtor-in-possession financings. The Fund may participate in or acquire debtor-in-possession financings (commonly known as “DIP financings”). DIP financings are arranged when an entity seeks the protections of the bankruptcy court under Chapter 11 of the U.S. bankruptcy code. These financings allow the entity to continue its business operations while reorganizing under Chapter 11. Such financings constitute senior liens on unencumbered security (i.e., security not subject to other creditors’ claims). There is a risk that the entity will not emerge from Chapter 11 and be forced to liquidate its assets under Chapter 7 of the U.S. Bankruptcy Code. In the event of liquidation, the Fund’s only recourse would be against the property securing the DIP financing.

Investments in mortgage-backed, asset-backed and other securities. The Fund may invest in mortgage-backed securities. Mortgage-backed securities may be issued by private issuers, by government-sponsored entities such as

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2457

---

---

Table of Contents

FNMA or FHLMC or by agencies of the U.S. government, such as GNMA. Mortgage-backed securities represent direct or indirect participation in, or are collateralized by and payable from, mortgage loans secured by real property. The commercial mortgages underlying certain commercial mortgage-backed securities generally allow all or a substantial portion of the loan balance to be paid at maturity, commonly known as a balloon payment. Some mortgage loans restrict periodic adjustments by limiting changes in the borrower’s monthly principal and interest payments rather than limiting interest rate changes. These payment caps may result in negative amortization, where payments are less than the amount of principal and interest owed, with excess amounts added to the outstanding principal balance, which can extend the average life of the mortgage-backed securities.

The Fund may invest in asset-backed securities and in securities issued by entities, such as trusts, whose underlying assets are municipal securities. The Fund may invest in collateralized debt obligations (CDOs), which include collateralized bond obligations (CBOs), collateralized loan obligations (CLOs) and other similarly structured securities. A CDO is a trust backed by a pool of fixed income securities. The trust typically is split into two or more portions, called tranches, which vary in credit quality and yield. Lower tranches pay higher interest rates but represent lower degrees of credit quality and are more sensitive to the rate of defaults in the pool of obligations. Certain CDOs may use derivatives, such as credit default swaps, to create synthetic exposure to assets rather than holding such assets directly.

Subordinated securities. The Fund may invest in securities that are subordinated or “junior” to more senior securities of the issuer. The investor in a subordinated security of an issuer is entitled to payment after other holders of debt in that issuer.

Zero coupon securities. The Fund may invest in zero coupon securities. Zero coupon securities are debt instruments that do not pay interest during the life of the security but are issued at a discount from the amount the investor will receive when the issuer repays the amount borrowed (the face value). The discount approximates the total amount of interest that would be paid at an assumed interest rate.

Derivatives. The Fund may, but is not required to, invest without limit in synthetic municipal securities and other structured securities, inverse floating rate obligations, credit default swaps and other derivatives. Credit default swaps can be used to acquire or to transfer the credit risk of a security or index of securities without buying or selling the security or securities comprising the relevant index. A derivative is a security or

58Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

instrument whose value is determined by reference to the value or the change in value of one or more securities, currencies, indices or other financial instruments. The Fund may use derivatives for a variety of purposes, including:

•	In an attempt to hedge against adverse changes in the market prices of securities, interest rates or currency exchange rates
•	As a substitute for purchasing or selling securities
•	To attempt to increase the Fund’s return as a non-hedging strategy that may be considered speculative
•	To manage portfolio characteristics (for example, the duration or credit quality of the Fund’s portfolio)
•	As a cash flow management technique

The Fund may choose not to make use of derivatives for a variety of reasons, and any use may be limited by applicable law and regulations. Derivative instruments are valued based on their mark-to market value in accordance with the Adviser’s valuation procedures adopted pursuant to Rule 2a-5 under the 1940 Act.

Inverse floating rate obligations. The Fund may invest in inverse floating rate obligations (a type of derivative instrument). Inverse floating rate obligations represent interests in tax-exempt bonds. Inverse floating rate obligations are created by depositing municipal bonds in a trust which divides the income stream of the underlying municipal bond into two parts: a short-term variable rate demand note and a residual interest bond (the inverse floating rate obligation) which receives interest based on the remaining cash flow of the trust after payment of interest on the note and various trust expenses. The interest rate on inverse floating rate obligations will generally decrease as short-term interest rates increase, and increase as short-term rates decrease. Due to their leveraged structure, the sensitivity of the market value of an inverse floating rate obligation to changes in interest rates is generally greater than a comparable long-term bond issued by the same issuer and with similar credit quality, redemption and maturity provisions. Inverse floating rate obligations may be volatile and involve leverage risk.

Other investment companies. The Fund may invest in the securities of other investment companies to the extent that such investments are consistent with the Fund’s investment objectives and principal investment strategies and permissible under the 1940 Act. Subject to the limitations on investment in other investment companies, the Fund may invest in

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2459

---

---

Table of Contents

exchange-traded funds (“ETFs”). The Fund does not currently intend to invest in investment companies that are not registered under the 1940 Act.

Repurchase agreements. In a repurchase agreement, the Fund purchases securities from a broker/dealer or a bank, called the counterparty, upon the agreement of the counterparty to repurchase the securities from the Fund at a later date, and at a specified price, which is typically higher than the purchase price paid by the Fund. The securities purchased serve as the Fund’s collateral for the obligation of the counterparty to repurchase the securities. If the counterparty does not repurchase the securities, the Fund is entitled to sell the securities, but the Fund may not be able to sell them for the price at which they were purchased, thus causing a loss. Additionally, if the counterparty becomes insolvent, there is some risk that the Fund will not have a right to the securities, or the immediate right to sell the securities.

Reverse repurchase agreements. The Fund may enter into reverse repurchase agreements, which involve the sale of securities held by the Fund subject to its agreement to repurchase the securities at an agreed-upon date or upon demand and at a price reflecting a market rate of interest. Reverse repurchase agreements are subject to the Fund’s limitation on borrowings and may be entered into only with banks or securities dealers or their affiliates. While a reverse repurchase agreement is outstanding, the Fund will maintain the segregation, either on its records or with the Fund’s custodian, of cash or other liquid securities, marked to market daily, in an amount at least equal to its obligations under the reverse repurchase agreement.

Reverse repurchase agreements involve the risk that the buyer of the securities sold by the Fund might be unable to deliver them when the Fund seeks to repurchase. If the buyer of securities under a reverse repurchase agreement files for bankruptcy or becomes insolvent, the buyer or trustee or receiver may receive an extension of time to determine whether to enforce the Fund’s obligation to repurchase the securities, and the Fund’s use of the proceeds of the reverse repurchase agreement may effectively be restricted pending such decision.

Use of leverage by the Fund. The Fund anticipates using leverage in order to pursue its investment objectives. The Fund may use leverage to the extent permitted by the 1940 Act. The Fund may source leverage initially and throughout the life of the Fund through a number of methods including through borrowings, issuing preferred shares, which have seniority over the common shares, the issuance of debt securities, entering into reverse repurchase agreements (effectively a borrowing), and investing in residual interest certificates of tender option bond trusts, also called inverse

60Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

floating rate securities, that have the economic effect of leverage because the Fund’s investment exposure to the underlying bonds held by the trust have been effectively financed by the trust’s issuance of floating rate certificates. The sources of leverage will vary depending on market conditions. The Fund anticipates using such leverage in an aggregate amount equal to approximately 30% of the Fund’s managed assets, if current market conditions persist. The Fund initially intends to leverage its assets through borrowings from banks and other financial institutions. It is expected that these borrowings will be made pursuant to a revolving credit facility established with a bank or other financial institution. Under the 1940 Act, the Fund is generally not permitted to incur indebtedness unless immediately after such borrowing the Fund has asset coverage of at least 300% of the aggregate outstanding principal balance of indebtedness. The fees and expenses attributed to leverage, including all offering expenses, will be borne by holders of common shares.

The Fund may not be leveraged at all times, and the amount of leverage, if any, may vary depending on a variety of factors, including the Adviser’s outlook for interest rates and credit markets and the costs that the Fund would incur as a result of such leverage. The Fund’s leveraging strategy may not be successful. By leveraging its investment portfolio, the Fund creates an opportunity for increased net income or capital appreciation. However, the use of leverage also creates risks for the Fund’s stockholders, including the likelihood of greater volatility of the Fund’s net asset value and market price. There is a risk that fluctuations in the interest rates on any leverage may adversely affect the return to the Fund’s stockholders. If the return on the securities purchased with such funds is not sufficient to cover the cost of leverage, the return on the Fund will be less than if leverage had not been used, and therefore the amount available for distribution to the Fund’s stockholders as dividends and other distributions will be reduced. Because the fees paid to the Adviser will be calculated on the basis of the Fund’s managed assets (which include the proceeds of leverage), the fees will be higher when leverage is utilized, giving the Adviser an incentive to utilize leverage. The Fund generally will not utilize leverage if it anticipates that it would result in a lower return to the Fund’s common stockholders over time.

If the Fund uses leverage, associated costs will be borne by common stockholders through a reduction of the NAV of the Fund’s common shares. Costs associated with leverage would likely include legal fees, audit fees, rating agency fees, structuring fees, commitment fees, and a usage (borrowing) fee. If the Fund issues preferred shares or debt, holders of preferred shares and holders of any debt issued by the Fund would not bear

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2461

---

---

Table of Contents

the advisory fee. Therefore, common stockholders bear the portion of the advisory fee attributable to the assets purchased with the proceeds of leverage.

Limited term and eligible tender offer. In accordance with the Fund’s charter, the Fund intends to terminate on the close of business on August 31, 2033 (the “Termination Date”); provided, that if the Board of Directors (the “Board”) believes that it is in the best interests of the Fund to do so, the Fund may extend the Termination Date: (i) once for up to one year (i.e., up to August 31, 2034), and (ii) once for up to an additional six months (i.e., up to February 28, 2035 (which date shall then become the Termination Date)), in each case upon the affirmative vote of a majority of the entire Board and without stockholder approval. In determining whether to extend the Termination Date, the Board may consider the inability to sell the Fund’s assets in a time frame consistent with termination due to lack of market liquidity or other extenuating circumstances. Additionally, the Board may determine that market conditions are such that it is reasonable to believe that, with an extension, the Fund’s remaining assets will appreciate and generate income in an amount that, in the aggregate, is meaningful relative to the cost and expense of continuing the operation of the Fund.

Beginning one year before the Termination Date (the “wind-down period”), the Fund may begin liquidating all or a portion of the Fund’s portfolio, and may deviate from its investment policies and may not achieve its investment objectives. In addition, within twelve months preceding the Termination Date, the Board may (but is not required to) cause the Fund to conduct an Eligible Tender Offer. An Eligible Tender Offer would consist of a tender offer to all common stockholders to purchase common shares of the Fund at a price equal to the net asset value (“NAV”) per common share on the expiration date of the tender offer. The Board has established that, following an Eligible Tender Offer, the Fund must have at least $100 million of net assets to ensure the continued viability of the Fund (the “Termination Threshold”).

In an Eligible Tender Offer, the Fund will offer to purchase all common shares held by each common stockholder; provided, that if the number of properly tendered common shares would result in the Fund’s net assets totaling less than the Termination Threshold, the Eligible Tender Offer will be terminated and no common shares will be repurchased pursuant to the Eligible Tender Offer. Instead, the Fund will begin (or continue) liquidating its portfolio and proceed to terminate on or before the Termination Date. The Adviser will pay all costs and expenses associated with the making of an Eligible Tender Offer, other than brokerage and related transaction costs associated with disposition of portfolio investments in connection with the

62Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

Eligible Tender Offer, which will be borne by the Fund and its stockholders. An Eligible Tender Offer would be made, and common stockholders would be notified thereof, in accordance with the requirements of the Investment Company Act of 1940 (the “1940 Act”), the Securities Exchange Act of 1934 (the “Exchange Act”) and the applicable tender offer rules thereunder (including Rule 13e-4 and Regulation 14E under the Exchange Act).

If the number of properly tendered common shares would result in the Fund’s net assets totaling greater than the Termination Threshold, all common shares properly tendered and not withdrawn will be purchased by the Fund pursuant to the terms of the Eligible Tender Offer. Following the completion of the Eligible Tender Offer, the Board may eliminate the Termination Date upon the affirmative vote of a majority of the Board and without stockholder approval and provide for the Fund’s perpetual existence. In making a decision to eliminate the Termination Date to provide for the Fund’s perpetual existence, the Board will take such actions with respect to the continued operations of the Fund as it deems to be in the best interests of the Fund, based on market conditions at such time, the extent of common stockholder participation in the Eligible Tender Offer and all other factors deemed relevant by the Board in consultation with the Adviser, taking into account that the Adviser may have a potential conflict of interest in seeking to convert to a perpetual fund.

The Fund is not a so called “target date” or “life cycle” fund whose asset allocation becomes more conservative over time as its target date, often associated with retirement, approaches. In addition, the Fund is not a “target term” fund whose investment objective is to return its original NAV on the Termination Date. The Fund’s investment objectives and policies are not designed to seek to return to investors that purchase common shares in this offering their initial investment of $20.00 per common share on the Termination Date or in an Eligible Tender Offer, and such investors and investors that purchase common shares after the completion of this offering may receive more or less than their original investment upon termination or in an Eligible Tender Offer.

Upon its termination, the Fund will distribute substantially all of its net assets to common stockholders, after paying or otherwise providing for all charges, taxes, expenses and liabilities, whether due or accrued or anticipated, of the Fund, as may be determined by the Board.

PRINCIPAL RISKS

General. The Fund is a diversified, closed-end management investment company designed primarily as a long-term investment and not as a trading tool. The Fund is not a complete investment program and should be considered only as an addition to an investor’s existing portfolio of

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2463

---

---

Table of Contents

investments. Due to uncertainty inherent in all investments, there can be no assurance that the Fund will achieve its investment objectives.

Market price of shares. Common shares of closed-end funds frequently trade at a price lower than their NAV. This is commonly referred to as “trading at a discount.” This characteristic of shares of closed-end funds is a risk separate and distinct from the risk that the Fund’s NAV may decrease. Both long and short-term investors, including investors who sell their shares within a relatively short period after completion of the initial public offering, will be exposed to this risk. The Fund is designed primarily for long-term investors and should not be considered a vehicle for trading purposes.

Whether investors will realize a gain or loss upon the sale of the Fund’s Common Shares will depend upon whether the market value of the shares at the time of sale is above or below the price the investor paid, taking into account transaction costs, for the shares and is not directly dependent upon the Fund’s NAV. Because the market value of the Fund’s shares will be determined by factors such as the relative demand for and supply of the shares in the market, general market conditions and other factors beyond the control of the Fund, the Fund cannot predict whether its common shares will trade at, below or above NAV, or below or above the initial offering price for the shares.

Limited term risk. Unless the limited term provision of the Fund’s Charter is amended by the Board and stockholders in accordance with Maryland law and the Fund’s Charter, or unless the Fund completes an Eligible Tender Offer and converts to perpetual existence, the Fund intends to terminate on or about the Termination Date (as such date may be extended by the Board in accordance with the Fund’s Charter). The Fund is not a so called “target date” or “life cycle” fund whose asset allocation becomes more conservative over time as its target date, often associated with retirement, approaches. In addition, the Fund is not a “target term” fund whose investment objective is to return its original NAV on the Termination Date. The Fund’s investment objectives and policies are not designed to seek to return to investors that purchase common shares in this offering their initial investment of $20.00 per share on the Termination Date or in an Eligible Tender Offer, and such investors and investors that purchase shares after the completion of this offering may receive more or less than their original investment upon termination or in an Eligible Tender Offer.

Because the assets of the Fund will be liquidated in connection with the termination, the Fund will incur transaction costs in connection with dispositions of portfolio securities. The Fund does not limit its investments to securities having a maturity date prior to the Termination Date and may

64Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

be required to sell portfolio securities when it otherwise would not, including at times when market conditions are not favorable, which may cause the Fund to lose money. In particular, the Fund’s portfolio may still have large exposures to illiquid securities as the Termination Date approaches, and losses due to portfolio liquidation may be significant. During the wind-down period, beginning one year before the Termination Date, the Fund may begin liquidating all or a portion of the Fund’s portfolio, and may deviate from its investment policies and may not achieve its investment objectives. During the wind-down period, the Fund’s portfolio composition may change as more of its portfolio holdings are called or sold and portfolio holdings are disposed of in anticipation of liquidation. The disposition of portfolio investments by the Fund could cause market prices of such instruments, and hence the NAV and market price of the common shares, to decline. In addition, disposition of portfolio investments will cause the Fund to incur increased brokerage and related transaction expenses. The Fund may receive proceeds from the disposition of portfolio investments that are less than the valuations of such investments by the Fund. Rather than reinvesting the proceeds of matured, called or sold securities, the Fund may invest such proceeds in short-term or other lower yielding securities or hold the proceeds in cash, which may adversely affect its performance and the market price of the common shares. The Fund may distribute the proceeds in one or more liquidating distributions prior to the final liquidation, which may cause fixed expenses to increase when expressed as a percentage of assets under management. Upon a termination, it is anticipated that the Fund will have distributed substantially all of its net assets to common stockholders, although securities for which no market exists or securities trading at depressed prices, if any, may be placed in a liquidating trust. Such a liquidating trust will not register as an investment company under the 1940 Act. As a result, the holders of the interests in the liquidating trust will not receive the protections under the 1940 Act that are afforded to investors in registered investment companies. Stockholders will bear the costs associated with establishing and maintaining a liquidating trust, if necessary. Securities placed in a liquidating trust may be held for an indefinite period of time until they can be sold or pay out all of their cash flows. Additionally, the tax treatment of the liquidating trust’s assets may differ from the tax treatment applicable to such assets when held by the Fund. To the extent the costs associated with a liquidating trust exceed the value of the remaining securities, the liquidating trust trustees may determine to dispose of the remaining securities in a manner of their choosing. The Fund cannot predict the amount, if any, of securities that will be required to be placed in a liquidating trust.

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2465

---

---

Table of Contents

If the Fund conducts an Eligible Tender Offer, the Fund may be required to dispose of portfolio investments in connection with any reduction in the Fund’s outstanding leverage necessary in order to maintain the Fund’s desired leverage ratios following a tender offer. The risks related to the disposition of securities in connection with the Fund’s termination also would be present in connection with the disposition of securities in connection with an Eligible Tender Offer. In addition, the Fund’s purchase of tendered common shares pursuant to a tender offer will have tax consequences for tendering stockholders and may have tax consequences for non-tendering stockholders. All common stockholders remaining after a tender offer will be subject to proportionately higher expenses due to the reduction in the Fund’s total assets. The reduction in the Fund’s total assets may also result in less investment flexibility, reduced diversification and greater volatility for the Fund and the common shares, and may have an adverse effect on the Fund’s investment performance.

The Adviser may have a conflict of interest in recommending to the Board that the Termination Date be eliminated and the Fund have a perpetual existence. The Fund is not required to conduct additional tender offers following an Eligible Tender Offer and conversion to perpetual existence. Therefore, remaining common stockholders may not have another opportunity to participate in a tender offer. Shares of closed-end management investment companies frequently trade at a discount from their NAV, and as a result remaining stockholders may only be able to sell their common shares at a discount to NAV.

Market risk. The market prices of securities or other assets held by the Fund may go up or down, sometimes rapidly or unpredictably, due to general market conditions, such as real or perceived adverse economic, political, or regulatory conditions, political instability, recessions, inflation, changes in interest or currency rates, lack of liquidity in the bond markets, the spread of infectious illness or other public health issues, weather or climate events, armed conflict, market disruptions caused by tariffs, trade disputes, sanctions or other government actions, or other factors or adverse investor sentiment. If the market prices of the Fund’s securities and assets fall, the value of your investment will go down. A change in financial condition or other event affecting a single issuer or market may adversely impact securities markets as a whole.

Changes in market conditions may not have the same impact on all types of securities. The value of securities may also fall due to specific conditions that affect a particular sector of the securities market or a particular issuer. In the past decade, financial markets throughout the world have experienced increased volatility, depressed valuations, decreased liquidity and heightened uncertainty. Governmental and non-governmental issuers

66Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

have defaulted on, or been forced to restructure, their debts. These conditions may continue, recur, worsen or spread. Events that have contributed to these market conditions include, but are not limited to, major cybersecurity events; geopolitical events (including wars, terror attacks and economic sanctions); measures to address budget deficits; downgrading of sovereign debt; changes in oil and commodity prices; dramatic changes in currency exchange rates; global pandemics; and public sentiment. The long-term impact of the COVID-19 pandemic and its subsequent variants on economies, markets, industries and individual issuers, are not known. Some sectors of the economy and individual issuers have experienced or may experience particularly large losses. Periods of extreme volatility in the financial markets; reduced liquidity of many instruments; increased government debt, inflation and disruptions to supply chains, consumer demand and employee availability, may continue for some time.

Raising the ceiling on U.S. government debt has become increasingly politicized. Any failure to increase the total amount that the U.S. government is authorized to borrow could lead to a default on U.S. government obligations, with unpredictable consequences for economies and markets in the U.S. and elsewhere. Inflation and interest rates have increased and may rise further. These circumstances could adversely affect the value and liquidity of the Fund's investments, and negatively impact the Fund's performance. In addition, inflation, rising interest rates, global supply chain disruptions and other market events could adversely affect the companies or issuers in which the Fund invests. Following Russia’s invasion of Ukraine, Russian securities lost all, or nearly all, their market value. Other securities or markets could be similarly affected by past or future political, geopolitical or other events or conditions.

Governments and central banks, including the U.S. Federal Reserve, have taken extraordinary and unprecedented actions to support local and global economies and the financial markets. These actions have resulted in significant expansion of public debt, including in the U.S. The consequences of high public debt, including its future impact on the economy and securities markets, may not be known for some time. U.S. Federal Reserve or other U.S. or non-U.S. governmental or central bank actions, including increases or decreases in interest rates, or contrary actions by different governments, could negatively affect financial markets generally, increase market volatility and reduce the value and liquidity of securities in which the Fund invests. Policy and legislative changes in the U.S. and in other countries are affecting many aspects of financial regulation, and these and other events affecting global markets, such as the United Kingdom’s exit from the European Union (or Brexit), potential trade imbalances with China

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2467

---

---

Table of Contents

or other countries, or sanctions or other government actions against Russia, other nations or individuals or companies (or their countermeasures), may contribute to decreased liquidity and increased volatility in the financial markets. The impact of these changes on the markets, and the implications for market participants, may not be fully known for some time.

The U.S. and other countries are periodically involved in disputes over trade and other matters, which may result in tariffs, investment restrictions and adverse impacts on affected companies and securities. For example, the U.S. has imposed tariffs and other trade barriers on Chinese exports, has restricted sales of certain categories of goods to China, and has established barriers to investments in China. Trade disputes may adversely affect the economies of the U.S. and its trading partners, as well as companies directly or indirectly affected and financial markets generally. The U.S. government has prohibited U.S. persons, such as the Fund, from investing in Chinese companies designated as related to the Chinese military. The Chinese government is involved in a longstanding dispute with Taiwan that has included threats of invasion. If the political climate between the U.S. and China does not improve or continues to deteriorate, if China were to attempt unification of Taiwan by force, or if other geopolitical conflicts develop or get worse, economies, markets and individual securities may be severely affected both regionally and globally, and the value of the Fund’s assets may go down.

Economies and financial markets throughout the world are increasingly interconnected. Economic, financial or political events, trading and tariff arrangements, armed conflict such as between Russia and Ukraine or in the Middle East, terrorism, natural disasters, infectious illness or public health issues, cybersecurity events, supply chain disruptions, sanctions against Russia, other nations or individuals or companies and possible countermeasures, and other circumstances in one country or region could have profound impacts on other countries or regions and on global economies or markets. As a result, whether or not the Fund invests in securities of issuers located in or with significant exposure to the countries or regions directly affected, the value and liquidity of the Fund’s investments may be negatively affected. The Fund may experience a substantial or complete loss on any security or derivative position.

Municipal securities risk. The municipal bond market can be susceptible to unusual volatility, particularly for lower-rated and unrated securities. Liquidity can be reduced unpredictably in response to overall economic conditions or credit tightening. Issuers of municipal securities tend to derive a significant portion of their revenue from taxes, particularly property and income taxes, and decreases in personal income levels and property values and other unfavorable economic factors, such as a general

68Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

economic recession, adversely affect municipal securities. Municipal issuers may also be adversely affected by rising health care costs, increasing unfunded pension liabilities and by the phasing out of federal programs providing financial support. Where municipal securities are issued to finance particular projects, especially those relating to education, health care, transportation, housing, water or sewer and utilities, issuers often depend on revenues from those projects to make principal and interest payments. Adverse conditions and developments in those sectors can result in lower revenues to issuers of municipal securities, potentially resulting in defaults, and can also have an adverse effect on the broader municipal securities market. To the extent the Fund invests significantly in a single state, or in securities the payments on which are dependent upon a single project or source of revenues, or that relate to a sector or industry, including health care facilities, education, special revenues and housing, the Fund will be more susceptible to associated risks and developments.

There may be less public information available on municipal issuers or projects than other issuers, and valuing municipal securities may be more difficult. In addition, the secondary market for municipal securities is less well developed and liquid than other markets, and dealers may be less willing to offer and sell municipal securities in times of market turbulence. Changes in the financial condition of one or more individual municipal issuers (or one or more insurers of municipal issuers), or one or more defaults by municipal issuers or insurers, can adversely affect liquidity and valuations in the overall market for municipal securities. The value of municipal securities can also be adversely affected by regulatory and political developments affecting the ability of municipal issuers to pay interest or repay principal, actual or anticipated tax law changes or other legislative actions, and by uncertainties and public perceptions concerning these and other factors. Municipal securities may be more susceptible to downgrades or defaults during recessions or similar periods of economic stress. Financial difficulties of municipal issuers may continue or get worse, particularly in the event of political, economic or market turmoil or a recession.

The rate of interest paid on municipal securities normally is lower than the rate of interest paid on fully taxable securities. Some municipal securities, such as general obligation issues, are backed by the issuer’s taxing authority, while other municipal securities, such as revenue issues, are backed only by revenues from certain facilities or other sources and not by the issuer itself. The payment of principal and interest on private activity and industrial development revenue bonds is solely dependent on the ability of the facility’s user to meet its financial obligations and the pledge, if any, of the facility or other property as security for payment.

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2469

---

---

Table of Contents

The municipal market can be susceptible to unusual volatility, particularly for lower-rated and unrated securities.

Taxable investment risk. Although distributions of interest income from the Fund’s tax-exempt securities are generally exempt from regular federal income tax, distributions from other sources, including capital gain distributions, and any gains on the sale of your shares are not. In addition, the interest on the Fund’s municipal securities could become subject to regular federal income tax or the AMT due to noncompliant conduct by issuers, unfavorable legislation or litigation, or adverse interpretations by regulatory authorities. You should consult a tax Adviser about whether the AMT applies to you and about state and local taxes on your Fund distributions.

“High yield” or “junk” bond risk. Debt securities that are below investment grade, called “junk bonds,” are speculative, have a higher risk of default or are already in default, tend to be less liquid and are more difficult to value than higher grade securities and may involve major risk of exposure to adverse conditions and negative sentiments. These securities have a higher risk of issuer default because, among other reasons, issuers of junk bonds often have more debt in relation to total capitalization than issuers of investment grade securities. Junk bonds tend to be volatile and more susceptible to adverse events and negative sentiments. These risks are more pronounced for securities that are already in default. The Fund may not receive interest payments on defaulted securities and may incur costs to protect its investment. In addition, defaulted securities involve the substantial risk that principal will not be repaid. Changes in economic conditions or developments regarding the individual issuer are more likely to cause price volatility and weaken the capacity of such securities to make principal and interest payments than is the case for higher grade debt securities. The value of lower-quality debt securities often changes in response to issuer, political, or economic developments and can decline significantly over short as well as long periods of time or during periods of general or regional economic difficulty. Junk bonds may also be less liquid than higher-rated securities, which means that the Fund may have difficulty selling them at times, and it may have to apply a greater degree of judgment in establishing a price for purposes of valuing Fund shares. Junk bonds generally are issued by less creditworthy issuers. Issuers of junk bonds may have a larger amount of outstanding debt securities relative to their assets than issuers of investment grade bonds. In the event of an issuer’s bankruptcy, claims of other creditors may have priority over the claims of junk bond holders, leaving few or no assets available to repay junk bond holders. The Fund may incur expenses to the extent necessary to seek recovery upon default or to negotiate new terms with a defaulting

70Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

issuer. Junk bonds frequently have redemption features that permit an issuer to repurchase the security from the Fund before it matures. If the issuer redeems junk bonds, the Fund may have to invest the proceeds in bonds with lower yields and may lose income.

Interest rate risk. The market prices of the Fund's fixed income securities may fluctuate significantly when interest rates change. The value of your investment will generally go down when interest rates rise. A rise in rates tends to have a greater impact on the prices of longer term or duration securities. For example, if interest rates increase by 1%, the value of a Fund’s portfolio with a portfolio duration of ten years would be expected to decrease by 10%, all other things being equal. In recent years interest rates and credit spreads in the U.S. have been at historic lows. The U.S. Federal Reserve has raised certain interest rates, and interest rates may continue to go up. A general rise in interest rates could adversely affect the price and liquidity of fixed income securities. The maturity of a security may be significantly longer than its effective duration. A security’s maturity and other features may be more relevant than its effective duration in determining the security’s sensitivity to other factors affecting the issuer or markets generally, such as changes in credit quality or in the yield premium that the market may establish for certain types of securities (sometimes called “credit spread”). In general, the longer its maturity the more a security may be susceptible to these factors. When the credit spread for a fixed income security goes up, or “widens,” the value of the security will generally go down.

Rising interest rates can lead to increased default rates, as issuers of floating rate securities find themselves faced with higher payments. Unlike fixed rate securities, floating rate securities generally will not increase in value if interest rates decline. Changes in interest rates also will affect the amount of interest income the Fund earns on its floating rate investments.

Credit risk. If an issuer or guarantor of a security held by the Fund or a counterparty to a financial contract with the Fund defaults on its obligation to pay principal and/or interest, has its credit rating downgraded or is perceived to be less creditworthy, or the credit quality or value of any underlying assets declines, the value of your investment will typically decline. Changes in actual or perceived creditworthiness may occur quickly. The Fund could be delayed or hindered in its enforcement of rights against an issuer, guarantor or counterparty.

Prepayment or call risk. Many issuers have a right to prepay their securities. If interest rates fall, an issuer may exercise this right. If this happens, the Fund will not benefit from the rise in market price that normally accompanies a decline in interest rates, and will be forced to

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2471

---

---

Table of Contents

reinvest prepayment proceeds at a time when yields on securities available in the market are lower than the yield on the prepaid security. The Fund also may lose any premium it paid on the security.

Extension risk. During periods of rising interest rates, the average life of certain types of securities may be extended because of slower than expected principal payments. This may lock in a below market interest rate, increase the security’s duration and reduce the value of the security.

Risk of illiquid investments. Certain securities and derivatives held by the Fund may be impossible or difficult to purchase, sell or unwind. Illiquid securities and derivatives also may be difficult to value. Liquidity risk may be magnified in an environment of rising interest rates or widening credit spreads. During times of market turmoil, there have been, and may be, no buyers or sellers for securities in entire asset classes. If the Fund is forced to sell an illiquid asset or unwind a derivatives position, the Fund may suffer a substantial loss or may not be able to sell at all.

Portfolio selection risk. The Adviser’s judgment about the quality, relative yield, relative value or market trends affecting a particular sector or region, market segment, security, industry or about interest rates or other market factors may prove to be incorrect or may not produce the desired results, or there may be imperfections, errors or limitations in the models, tools and information used by the Adviser.

Small and mid-size issuers risk. Compared with those of larger municipal issuers, securities of small and mid-size municipal issuers may experience sharper swings in market values, have limited liquidity, be harder to value or to sell at the times and prices the Adviser thinks appropriate, and offer greater potential for gain and loss.

Risks of subordinated securities. A holder of securities that are subordinated or “junior” to more senior securities of an issuer is entitled to payment after holders of more senior securities of the issuer. Subordinated securities are more likely to suffer a credit loss than non-subordinated securities of the same issuer, any loss incurred by the subordinated securities is likely to be proportionately greater, and any recovery of interest or principal may take more time. As a result, even a perceived decline in creditworthiness of the issuer is likely to have a greater impact on subordinated securities than more senior securities.

Debtor-in-possession financings risk. Debtor-in-possession financings are loans to a debtor-in-possession in a proceeding under the U.S. Bankruptcy Code that have been approved by the bankruptcy court. These financings allow the entity to continue its business operations while reorganizing under Chapter 11 of the U.S. Bankruptcy Code. Debtor-in-possession

72Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

financings can provide creditors with varying levels of protection, as they may carry super-priority repayment status, be secured by a lien on the borrower’s otherwise unencumbered assets, or be secured by a junior lien on the borrower’s encumbered assets. These financings are subject to the risk that the borrower will not emerge successfully from the bankruptcy/reorganization proceedings and will be forced to liquidate its assets. In the event of liquidation, the Fund’s only recourse will be against the property securing the debtor-in-possession loan and any remaining unencumbered assets, which might be insufficient to repay the debtor-in-possession loan in full.

U.S. Treasury obligations risk. The market value of direct obligations of the U.S. Treasury may vary due to changes in interest rates. In addition, changes to the financial condition or credit rating of the U.S. government may cause the value of the Fund’s investments in obligations issued by the U.S. Treasury to decline.

U.S. government agency obligations risk. The Fund invests in obligations issued by agencies and instrumentalities of the U.S. government. Government-sponsored entities such as the Federal National Mortgage Association (“FNMA”), the Federal Home Loan Mortgage Corporation (“FHLMC”) and the Federal Home Loan Banks (“FHLBs”), although chartered or sponsored by Congress, are not funded by congressional appropriations and the debt and mortgage-backed securities issued by them are neither guaranteed nor issued by the U.S. government. The maximum potential liability of the issuers of some U.S. government obligations may greatly exceed their current resources, including any legal right to support from the U.S. government. Such debt and mortgage-backed securities are subject to the risk of default on the payment of interest and/or principal, similar to debt of private issuers. Although the U.S. government has provided financial support to FNMA and FHLMC in the past, there can be no assurance that it will support these or other government-sponsored entities in the future.

Mortgage-related and asset-backed securities risk. The value of mortgage-related securities, including commercial mortgage-backed securities, collateralized mortgage-backed securities, credit risk transfer securities, and asset-backed securities, will be influenced by factors affecting the assets underlying such securities. As a result, during periods of declining asset value, difficult or frozen credit markets, swings in interest rates, or deteriorating economic conditions, mortgage-related and asset-backed securities may decline in value, face valuation difficulties, become more volatile and/or become illiquid. Mortgage-backed securities tend to be more sensitive to changes in interest rate than other types of debt securities. These securities are also subject to interest rate,

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2473

---

---

Table of Contents

prepayment and extension risks. Some of these securities may receive little or no collateral protection from the underlying assets and are thus subject to the risk of default. The risk of such defaults is generally higher in the case of mortgage-backed investments offered by non-governmental issuers and those that include so-called “sub-prime” mortgages. The structure of some of these securities may be complex and there may be less available information than for other types of debt securities. Upon the occurrence of certain triggering events or defaults, the Fund may become the holder of underlying assets at a time when those assets may be difficult to sell or may be sold only at a loss.

Risks of investing in collateralized debt obligations. Investment in a collateralized debt obligation (CDO) is subject to the credit, subordination, interest rate, valuation, prepayment, extension and other risks of the obligations underlying the CDO and the tranche of the CDO in which the Fund invests. CDOs are subject to liquidity risk. CDOs carry additional risks including, but not limited to: (i) the possibility that distributions from collateral securities will not be adequate to make interest or other payments; (ii) the risk that the collateral may default or decline in value or be downgraded, if rated by a nationally recognized statistical rating organization; (iii) the structure and complexity of the transaction and the legal documents could lead to disputes among investors regarding the characterization of proceeds; (iv) the investment return achieved by the Fund could be significantly different than those predicted by financial models; (v) the lack of a readily available secondary market for CDOs; (vi) the risk of forced “fire sale” liquidation due to technical defaults such as coverage test failures; and (vii) the CDO’s manager may perform poorly. In addition, investments in CDOs may be characterized by the Fund as illiquid securities. CDOs may be highly leveraged (which could make them highly volatile). Synthetic CDOs are also subject to the risks of investing in derivatives, such as credit default swaps, and leverage risk. The Fund may invest in or be exposed to CDOs that are sometimes referred to as “covenant-lite” obligations, which generally are debt obligations that lack financial maintenance covenants or possess fewer or contingent financial maintenance covenants and other financial protections for lenders and investors. These “covenant-lite” obligations typically are particularly subject to the risks associated with investments in loans.

Risks of instruments that allow for balloon payments or negative amortization payments. Certain debt instruments allow for balloon payments or negative amortization payments. Such instruments permit the borrower to avoid paying currently a portion of the interest accruing on the instrument. While these features make the debt instrument more affordable to the borrower in the near term, they increase the risk that the borrower

74Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

will be unable to make the resulting higher payment or payments that become due at the maturity of the loan.

Derivatives risk. Using synthetic municipal securities, inverse floating rate obligations, credit default swaps and other derivatives can increase Fund losses and reduce opportunities for gains when market prices, interest rates or the derivative instruments themselves behave in a way not anticipated by the Fund. Using derivatives may increase the volatility of the Fund’s net asset value and may not provide the result intended. Derivatives may have a leveraging effect on the Fund. Some derivatives have the potential for unlimited loss, regardless of the size of the Fund’s initial investment. Derivatives are generally subject to the risks applicable to the assets, rates, indices or other indicators underlying the derivative. Changes in a derivative’s value may not correlate well with the referenced asset or metric. The Fund also may have to sell assets at inopportune times to satisfy its obligations. Derivatives may be difficult to sell, unwind or value, and the counterparty may default on its obligations to the Fund. Use of derivatives may have different tax consequences for the Fund than an investment in the underlying security, and such differences may affect the amount, timing and character of income distributed to stockholders. The U.S. government and foreign governments have adopted and implemented or are in the process of adopting and implementing regulations governing derivatives markets, including mandatory clearing of certain derivatives, margin and reporting requirements. The ultimate impact of the regulations remains unclear. Additional regulation of derivatives may make them more costly, limit their availability or utility, otherwise adversely affect their performance or disrupt markets.

Synthetic municipal securities risk. The tax-exempt character of the interest paid on tender option bonds, bond receipts and similar synthetic municipal securities, a type of derivative instrument, is based on the tax-exempt income stream from the collateral. In addition to the risks of investing in municipal securities and in derivatives generally, investments in synthetic municipal securities are subject to the risk that income derived from such securities is deemed to be taxable.

Risks of investing in inverse floating rate obligations. The interest rate on inverse floating rate obligations will generally decrease as short-term interest rates increase, and increase as short-term rates decrease. Due to their leveraged structure, the sensitivity of the market value of an inverse floating rate obligation to changes in interest rates is generally greater than a comparable long-term bond issued by the same issuer and with similar credit quality, redemption and maturity provisions. Inverse floating rate obligations may be volatile and involve leverage risk.

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2475

---

---

Table of Contents

Credit default swap risk. Credit default swap contracts, a type of derivative instrument, involve special risks and may result in losses to the Fund. Credit default swaps may in some cases be illiquid, and they increase credit risk since the Fund has exposure to the issuer of the referenced obligation and either the counterparty to the credit default swap or, if it is a cleared transaction, the brokerage firm through which the trade was cleared and the clearing organization that is the counterparty to that trade.

Structured securities risk. Structured securities may behave in ways not anticipated by the Fund, or they may not receive the tax, accounting or regulatory treatment anticipated by the Fund.

Leverage risk. When the Fund uses leverage through issuing preferred shares or borrowing or otherwise engages in transactions that have a leveraging effect on the Fund’s portfolio, the value of the Fund will be more volatile and all other risks will tend to be compounded. This is because leverage generally magnifies the effect of any increase or decrease in the value of the Fund’s underlying assets or creates investment risk with respect to a larger pool of assets than the Fund would otherwise have, potentially resulting in the loss of all assets. Engaging in such transactions may cause the Fund to liquidate positions when it may not be advantageous to do so. New derivatives regulations require the Fund, to the extent it uses derivatives to a material extent, to, among other things, comply with certain overall limits on leverage. These regulations may limit the ability of the Fund to pursue its investment strategies and may not be effective to mitigate the Fund’s risk of loss from derivatives.

The Fund may use financial leverage on an ongoing basis for investment purposes by borrowing from banks through a revolving credit facility and by engaging in certain other forms of leverage, including investments in inverse floating rate securities. The fees and expenses attributed to leverage, including any increase in the management fees, will be borne by holders of common shares. Since the Adviser’s fee is based on a percentage of the Fund’s managed assets, its fee will be higher if the Fund is leveraged, and the Adviser will thus have an incentive to leverage the Fund.

Risks of zero coupon bonds, payment in kind, deferred and contingent payment securities. These securities may be more speculative and may fluctuate more in value than securities which pay income periodically and in cash. In addition, although the Fund receives no periodic cash payments on such securities, the Fund is deemed for tax purposes to receive income from such securities, which applicable tax rules require the Fund to distribute to stockholders. Such distributions may be taxable when distributed to stockholders.

76Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

Repurchase agreement risk. In the event that the other party to a repurchase agreement defaults on its obligations, the Fund may encounter delay and incur costs before being able to sell the security. Such a delay may involve loss of interest or a decline in price of the security. In addition, if the Fund is characterized by a court as an unsecured creditor, it would be at risk of losing some or all of the principal and interest involved in the transaction.

Market segment risk. To the extent the Fund emphasizes, from time to time, investments in a market segment, the Fund will be subject to a greater degree to the risks particular to that segment, and may experience greater market fluctuation than a fund without the same focus.

Valuation risk. Nearly all of the Fund's investments are valued using a fair value methodology. The sales price the Fund could receive for any particular portfolio investment may differ from the Fund’s valuation of the investment, particularly for illiquid securities and securities that trade in thin or volatile markets. These differences may increase significantly and affect Fund investments more broadly during periods of market volatility. The ability to value the Fund’s investments may also be impacted by technological issues and/or errors by pricing services or other third party service providers.

Cybersecurity risk. Cybersecurity failures by and breaches of the Fund’s Adviser, transfer agent, custodian, Fund accounting agent or other service providers may disrupt Fund operations, interfere with the Fund’s ability to calculate its NAV, prevent Fund stockholders from purchasing or selling shares or receiving distributions or receiving timely information regarding the Fund or their investment in the Fund, cause loss of or unauthorized access to private stockholder information, and result in financial losses to the Fund and its stockholders, regulatory fines, penalties, reputational damage, or additional compliance costs. New ways to carry out cyber attacks continue to develop. Therefore, there is a chance that some risks have not been identified or prepared for, or that an attack may not be detected, which puts limitations on the Fund’s ability to plan for or respond to a cyber attack.

Cash management risk. The value of the investments held by the Fund for cash management or temporary defensive purposes may be affected by market risks, changing interest rates and by changes in credit ratings of the investments. To the extent that the Fund has any uninvested cash, the Fund would be subject to credit risk with respect to the depository institution holding the cash. If the Fund holds cash uninvested, the Fund

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2477

---

---

Table of Contents

will not earn income on the cash and the Fund’s yield will go down. During such periods, it may be more difficult for the Fund to achieve its investment objectives.

Anti-takeover provisions. The Fund’s Charter and Bylaws include provisions that are designed to limit the ability of other entities or persons to acquire control of the Fund for short-term objectives, including by converting the Fund to open-end status or changing the composition of the Board, that may be detrimental to the Fund’s ability to achieve its primary investment objective of seeking to provide its common stockholders with a high level of current income exempt from regular federal income tax. These provisions include staggered terms of service for the Directors, advance notice requirements for stockholder proposals, and super-majority voting requirements for certain transactions with affiliates, open-ending the Fund or a merger, liquidation, asset sale or similar transaction. The Fund’s Bylaws also contain a provision providing that the Board of Directors has adopted a resolution to opt in the Fund to the provisions of the Maryland Control Share Acquisition Act (“MCSAA”). Such provisions may limit the ability of stockholders to sell their shares at a premium over prevailing market prices by discouraging a third party from seeking to obtain control of the Fund. There can be no assurance, however, that such provisions will be sufficient to deter activist investors that seek to cause the Fund to take actions that may not be aligned with the interests of long-term stockholders Furthermore, the law is uncertain on the use of control share provisions. Certain courts have found that control share provisions are unenforceable under the 1940 Act. It is possible that a court could decide that the Fund’s decision to opt in to the MCSAA is not enforceable under the 1940 Act.

Exclusive forum provisions.  The Fund’s Bylaws designate the Circuit Court for Baltimore City, Maryland as the sole and exclusive forum for certain types of actions and proceedings that may be initiated by the Fund’s stockholders and provide that claims relating to causes of action under the United States federal securities laws may only be brought in the United States District Court for the District of Maryland, Northern Division, which could limit stockholders’ ability to obtain a favorable judicial forum for disputes with the Fund or its directors, officers or the Fund’s agents, if any, and could discourage lawsuits against the Fund and its directors, officers and agents, if any.

The Fund’s Bylaws provide that, unless the Fund consents in writing to the selection of an alternative forum, the Circuit Court for Baltimore City, Maryland, or, if that court does not have jurisdiction, the United States District Court for the District of Maryland, Northern Division, will be the sole and exclusive forum for (a) any Internal Corporate Claim, as such term is defined in the MGCL, (b) any derivative action or proceeding brought on

78Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

the Fund’s behalf (other than actions arising under federal securities laws), (c) any action asserting a claim of breach of any duty owed by any of the Fund’s directors, officers or other agents to the Fund or to the Fund’s stockholders, (d) any action asserting a claim against the Fund or any of the Fund’s directors, officers or other agents arising pursuant to any provision of the MGCL or the Fund’s Charter or Bylaws or (e) any other action asserting a claim against the Fund or any of the Fund’s directors, officers or other agents that is governed by the internal affairs doctrine. Furthermore, the Fund’s Bylaws provide that, unless the Fund consents in writing to the selection of an alternative forum, the United States District Court for the District of Maryland, Northern Division shall, to the fullest extent permitted by law, be the sole and exclusive forum for the resolution of any claim arising under the United States federal securities laws.

These exclusive forum provisions may limit the ability of the Fund’s stockholders to bring a claim in a judicial forum that such stockholders find favorable for disputes with the Fund or the Fund’s directors, officers, or agents, if any, which may discourage such lawsuits against the Fund and the Fund’s directors, officers, and agents, if any. Alternatively, if a court were to find the choice of forum provisions contained in the Fund’s Bylaws to be inapplicable or unenforceable in an action, the Fund may incur additional costs associated with resolving such action in other jurisdictions, which could materially adversely affect the Fund’s business, financial condition, and operating results.

Please note that there are many other factors that could adversely affect your investment and that could prevent the Fund from achieving its goals.

An investment in the Fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

INVESTMENT RESTRICTIONS

The following are the Fund’s fundamental investment restrictions. These restrictions, along with the Fund’s investment objectives, may not be changed without the approval of the holders of a majority of the Fund’s outstanding voting securities (which for this purpose and under the 1940 Act means the lesser of (i) 67% of the common shares represented at a meeting at which more than 50% of the outstanding common shares are represented or (ii) more than 50% of the outstanding common shares).

The Fund may not:

(1)	The Fund may not borrow money except as permitted by (i) the 1940 Act, or interpretations or modifications by the SEC, SEC staff or

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2479

---

---

Table of Contents

	other authority of competent jurisdiction, or (ii) exemptive or other relief or permission from the SEC, SEC staff or other authority of competent jurisdiction.
(2)	The Fund may not engage in the business of underwriting the securities of other issuers except as permitted by (i) the 1940 Act, or interpretations or modifications by the SEC, SEC staff or other authority of competent jurisdiction, or (ii) exemptive or other relief or permission from the SEC, SEC staff or other authority of competent jurisdiction.
(3)	The Fund may lend money or other assets to the extent permitted by (i) the 1940 Act, or interpretations or modifications by the SEC, SEC staff or other authority of competent jurisdiction or (ii) exemptive or other relief or permission from the SEC, SEC staff or other authority of competent jurisdiction.
(4)	The Fund may not issue senior securities except as permitted by (i) the 1940 Act, or interpretations or modifications by the SEC, SEC staff or other authority of competent jurisdiction, or (ii) exemptive or other relief or permission from the SEC, SEC staff or other authority of competent jurisdiction.
(5)	The Fund may not purchase or sell real estate except as permitted by (i) the 1940 Act, or interpretations or modifications by the SEC, SEC staff or other authority of competent jurisdiction, or (ii) exemptive or other relief or permission from the SEC, SEC staff or other authority of competent jurisdiction.
(6)	The Fund may purchase or sell commodities or contracts related to commodities to the extent permitted by (i) the 1940 Act, or interpretations or modifications by the SEC, SEC staff or other authority of competent jurisdiction, or (ii) exemptive or other relief or permission from the SEC, SEC staff or other authority of competent jurisdiction.
(7)	Except as permitted by exemptive or other relief or permission from the SEC, SEC staff or other authority of competent jurisdiction, the Fund may not make any investment if, as a result, the Fund’s investments will be concentrated in any one industry.
(8)	Normally, the Fund invests at least 80% of its net assets (plus the amount of borrowings, if any, for investment purposes) in securities issued by or on behalf of states, counties, municipalities, territories and possessions of the United States and the District of Columbia and their authorities, political subdivisions, agencies and instrumentalities, the interest on which is exempt from regular federal income tax (“municipal securities”).

80Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

All other investment policies of the Fund are considered non-fundamental and may be changed by the Board of Directors without prior approval of the Fund’s outstanding voting shares.

More Information

For more detailed descriptions of the Fund’s investment policies, strategies and risks, see the Fund’s registration statement on Form N-2 that was declared effective by the Securities and Exchange Commission on August 4, 2021. The information in this report supersedes the information in the Fund’s registration statement to the extent there is any inconsistency.

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2481

---

---

Table of Contents

Effects of Leverage

The following table is furnished in response to requirements of the Securities and Exchange Commission. It is designed to illustrate the effects of leverage on common share total return, assuming investment portfolio total returns (consisting of income and changes in the value of investments held in the Fund’s portfolio) of -10%, -5%, 0%, 5% and 10%. The table below assumes the Fund’s continued use of leverage through borrowings under a credit agreement and certain other forms of leverage, including investments in inverse floating rate securities, as of April 30, 2024 as a percentage of the Fund’s total assets (which includes the assets attributable to such leverage), the annual rate of interest on the borrowings as of April 30, 2024, and the annual return that the Fund’s portfolio must experience (net of expenses) in order to cover such costs. The information below does not reflect the Fund’s use of certain other forms of economic leverage achieved through the use of other instruments or transactions not considered to be senior securities under the 1940 Act, if any.

The assumed investment portfolio returns in the table below are hypothetical figures and are not necessarily indicative of the investment portfolio returns experienced or expected to be experienced by the Fund. Your actual returns may be greater or less than those appearing below. In addition, actual borrowing expenses associated with borrowings by the Fund may vary frequently and may be significantly higher or lower than the rate used for the example below.

Borrowings under credit agreement as a percentage of total managed assets (including assets attributable to borrowings)	10.95%
Annual effective interest rate payable by Fund on borrowings	6.23%
Annual return Fund portfolio must experience (net of expenses) to cover interest rate on borrowings	0.68%
Common share total return for (10.00)% assumed portfolio total return	(12.00)%
Common share total return for (5.00)% assumed portfolio total return	(6.38)%
Common share total return for 0.00% assumed portfolio total return	(0.77)%
Common share total return for 5.00% assumed portfolio total return	4.85%
Common share total return for 10.00% assumed portfolio total return	10.46%

Common share total return is composed of two elements - investment income net of the Fund’s expenses, including any interest/dividends on assets resulting from leverage, and gains or losses on the value of the securities the Fund owns. As required by Securities and Exchange Commission rules, the table assumes that the Fund is more likely to suffer capital losses than to enjoy capital appreciation. For example, to assume a total return of 0%, the Fund must assume that the income it receives on its investments is entirely offset by losses in the value of those investments.

82Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

This table reflects hypothetical performance of the Fund’s portfolio and not the performance of the Fund’s common shares, the value of which will be determined by market forces and other factors.

Should the Fund elect to add additional leverage to its portfolio, the potential benefits of leveraging the Fund’s shares cannot be fully achieved until the proceeds resulting from the use of leverage have been received by the Fund and invested in accordance with the Fund’s investment objective and principal investment strategies. The Fund’s willingness to use additional leverage, and the extent to which leverage is used at any time, will depend on many factors, including, among other things, the Adviser’s assessment of the yield curve environment, interest rate trends, market conditions and other factors.

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2483

---

---

Table of Contents

Directors, Officers and Service Providers 

Investment Adviser and Administrator
Amundi Asset Management US, Inc.

Custodian and Sub-Administrator
The Bank of New York Mellon Corporation

Independent Registered Public Accounting Firm
Deloitte & Touche LLP

Legal Counsel
Morgan, Lewis & Bockius LLP

Transfer Agent
Equiniti Trust Company, LLC

Proxy Voting Policies and Procedures of the Fund are available without charge, upon request, by calling our toll free number (1-800-225-6292). Information regarding how the Fund voted proxies relating to portfolio securities during the most recent 12-month period ended June 30 is publicly available to stockholders at www.amundi.com/us. This information is also available on the Securities and Exchange Commission’s web site at www.sec.gov.

Directors and Officers

The Fund’s Directors and officers are listed below, together with their principal occupations and other directorships they have held during at least the past five years. Directors who are interested persons of the Fund within the meaning of the 1940 Act are referred to as Interested Directors. Directors who are not interested persons of the Fund are referred to as Independent Directors. Each of the Directors serves as a Director of each of the 46 U.S. registered investment portfolios for which Amundi US serves as investment adviser (the “Pioneer Funds”). The address for all Directors and all officers of the Fund is 60 State Street, Boston, Massachusetts 02109.

84Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

Independent Directors 

Name, Age and Position Held With the Fund	Term of Office and Length of Service	Principal Occupation(s) During At Least The Past Five Years	Other Directorships Held by Director During At Least The Past Five Years
Thomas J. Perna (73) Chairman of the Board and Director	Class III Director since 2021. Term expires in 2024.	Private investor (2004 – 2008 and 2013 – present); Chairman (2008 – 2013) and Chief Executive Officer (2008 – 2012), Quadriserv, Inc. (technology products for securities lending industry); and Senior Executive Vice President, The Bank of New York (financial and securities services) (1986 – 2004)	Director, Broadridge Financial Solutions, Inc. (investor communications and securities processing provider for financial services industry) (2009 – 2023); Director, Quadriserv, Inc. (2005 – 2013); and Commissioner, New Jersey State Civil Service Commission (2011 – 2015)
John E. Baumgardner, Jr. (73)* Director	Class I Director since 2021. Term expires in 2025.	Of Counsel (2019 – present), Partner (1983-2018), Sullivan & Cromwell LLP (law firm).	Chairman, The Lakeville Journal Company, LLC, (privately-held community newspaper group) (2015-present)
Diane Durnin (67) Director	Class II Director since 2021. Term expires in 2024.	Managing Director - Head of Product Strategy and Development, BNY Mellon Investment Management (investment management firm) (2012-2018); Vice Chairman – The Dreyfus Corporation (2005 – 2018): Executive Vice President Head of Product, BNY Mellon Investment Management (2007-2012); Executive Director- Product Strategy, Mellon Asset Management (2005-2007); Executive Vice President Head of Products, Marketing and Client Service, Dreyfus Corporation (investment management firm) (2000-2005); Senior Vice President Strategic Product and Business Development, Dreyfus Corporation (1994-2000)	None

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2485

---

---

Table of Contents

Independent Directors (continued)

Name, Age and Position Held With the Fund	Term of Office and Length of Service	Principal Occupation(s) During At Least The Past Five Years	Other Directorships Held by Director During At Least The Past Five Years
Benjamin M. Friedman (79) Director	Class II Director since 2021. Term expires in 2026.	William Joseph Maier Professor of Political Economy, Harvard University (1972 – present)	Trustee, Mellon Institutional Funds Investment Trust and Mellon Institutional Funds Master Portfolio (oversaw 17 portfolios in fund complex) (1989 - 2008)
Craig C. MacKay (61) Director	Class III Director since 2021. Term expires in 2024.	Partner, England & Company, LLC (advisory firm) (2012 – present); Group Head – Leveraged Finance Distribution, Oppenheimer & Company (investment bank) (2006 – 2012); Group Head – Private Finance & High Yield Capital Markets Origination, SunTrust Robinson Humphrey (investment bank) (2003 – 2006); and Founder and Chief Executive Officer, HNY Associates, LLC (investment bank) (1996 – 2003)	Director, Equitable Holdings, Inc. (financial services holding company) (2022 – present); Board Member of Carver Bancorp, Inc. (holding company) and Carver Federal Savings Bank, NA (2017 – present); Advisory Council Member, MasterShares ETF (2016 – 2017); Advisory Council Member, The Deal (financial market information publisher) (2015 – 2016); Board Co-Chairman and Chief Executive Officer, Danis Transportation Company (privately-owned commercial carrier) (2000 – 2003); Board Member and Chief Financial Officer, Customer Access Resources (privately-owned teleservices company) (1998 – 2000); Board Member, Federation of Protestant Welfare Agencies (human services agency) (1993 – present); and Board Treasurer, Harlem Dowling Westside Center (foster care agency) (1999 – 2018)

86Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

Name, Age and Position Held With the Fund	Term of Office and Length of Service	Principal Occupation(s) During At Least The Past Five Years	Other Directorships Held by Director During At Least The Past Five Years
Lorraine H. Monchak (68) Director	Class I Director since 2021. Term expires in 2025.	Chief Investment Officer, 1199 SEIU Funds (healthcare workers union pension funds) (2001 – present); Vice President – International Investments Group, American International Group, Inc. (insurance company) (1993 – 2001); Vice President Corporate Finance and Treasury Group, Citibank, N.A. (1980 – 1986 and 1990 – 1993); Vice President – Asset/Liability Management Group, Federal Farm Funding Corporation (government-sponsored issuer of debt securities) (1988 – 1990); Mortgage Strategies Group, Shearson Lehman Hutton, Inc. (investment bank) (1987 – 1988); Mortgage Strategies Group, Drexel Burnham Lambert, Ltd. (investment bank) (1986 – 1987)	None
Fred J. Ricciardi (77) Director	Class III Director since 2021. Term expires in 2024.	Private investor (2020 – present); Consultant (investment company services) (2012 – 2020); Executive Vice President, BNY Mellon (financial and investment company services) (1969 – 2012); Director, BNY International Financing Corp. (financial services) (2002 – 2012); Director, Mellon Overseas Investment Corp. (financial services) (2009 – 2012); Director, Financial Models (technology) (2005-2007); Director, BNY Hamilton Funds, Ireland (offshore investment companies) (2004-2007); Chairman/Director, AIB/BNY Securities Services, Ltd., Ireland (financial services) (1999-2006); Chairman, BNY Alternative Investment Services, Inc. (financial services) (2005-2007)	None
* Mr. Baumgardner is Of Counsel to Sullivan & Cromwell LLP, which acts as counsel to the Independent Directors of each Pioneer Fund.

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2487

---

---

Table of Contents

Interested Directors 

Name, Age and Position Held With the Fund	Term of Office and Length of Service	Principal Occupation(s) During At Least The Past Five Years	Other Directorships Held by Director During At Least The Past Five Years
Lisa M. Jones (62)** Director, President and Chief Executive Officer	Class I Director since 2021. Term expires in 2025.	Director, CEO and President of Amundi US, Inc. (investment management firm) (since September 2014); Director, CEO and President of Amundi Asset Management US, Inc. (since September 2014); Director, CEO and President of Amundi Distributor US, Inc. (since September 2014); Director, CEO and President of Amundi Asset Management US, Inc. (since September 2014); Chair, Amundi US, Inc., Amundi Distributor US, Inc. and Amundi Asset Management US, Inc. (September 2014 – 2018); Managing Director, Morgan Stanley Investment Management (investment management firm) (2010 – 2013); Director of Institutional Business, CEO of International, Eaton Vance Management (investment management firm) (2005 – 2010); Director of Amundi Holdings US, Inc. (since 2017)	Director of Clearwater Analytics (provider of web-based investment accounting software for reporting and reconciliation services) (September 2022 – present)
Macro Pirondini (57)** Director, Executive Vice President	Class II Director since January 2024. Term expires in 2026.	Executive Vice President and Chief Investment Officer of Amundi Asset Management US, Inc. since January 2024; Senior Managing Director and Head of Equities U.S. of Amundi US from 2010 to December 2023	None
** Ms. Jones and Mr. Pirondini are Interested Directors because they are an officer or director of the Fund’s investment adviser and certain of its affiliates.

88Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

Advisory Director 

Name, Age and Position Held With the Fund	Term of Office and Length of Service	Principal Occupation(s) During At Least The Past Five Years	Other Directorships Held by Director During At Least The Past Five Years
Marguerite A. Piret (75)*** Advisory Director	Advisory Director since January 2024 (Class III Director from 2021 to January 2024).	Chief Financial Officer, American Ag Energy, Inc. (technology for the environment, energy and agriculture) (2019 – present); Chief Operating Officer, North Country Growers LLC (controlled environment agriculture company) (2020 – present); Chief Executive Officer, Green Heat LLC (biofuels company) (2022 – present); President and Chief Executive Officer, Newbury Piret Company (investment banking firm) (1981 – 2019)	Director of New America High Income Fund, Inc. (closed-end investment company) (2004 – present); and Member, Board of Governors, Investment Company Institute (2000 – 2006)
*** Ms. Piret became a non-voting Advisory Director effective January 22, 2024.

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2489

---

---

Table of Contents

Fund Officers 

Name, Age and Position Held With the Fund	Term of Office and Length of Service	Principal Occupation(s) During At Least The Past Five Years	Other Directorships Held by Officer During At Least The Past Five Years
Christopher J. Kelley (59) Secretary and Chief Legal Officer	Since 2021. Serves at the discretion of the Board	Senior Vice President and Deputy General Counsel of Amundi US since March 2024; Vice President and Associate General Counsel of Amundi US from January 2008 to March 2024; Secretary and Chief Legal Officer of all of the Pioneer Funds since June 2010; Assistant Secretary of all of the Pioneer Funds from September 2003 to May 2010; Vice President and Senior Counsel of Amundi US from July 2002 to December 2007	None
Thomas Reyes (61) Assistant Secretary	Since 2021. Serves at the discretion of the Board	Associate General Counsel of Amundi US since March 2023; Assistant Secretary of all the Pioneer Funds since June 2010; Assistant General Counsel of Amundi US from May 2013 to March 2023 and Counsel of Amundi US from June 2007 to May 2013	None
Heather L. Melito-Dezan (47) Assistant Secretary	Since 2022. Serves at the discretion of the Board	Director - Trustee and Board Relationships of Amundi US since September 2019; Assistant Secretary of Amundi US, Inc. since July 2020: Assistant Secretary of Amundi Asset Management US, Inc. since July 2020: Assistant Secretary of Amundi Distributor US, Inc. since July 2020; Assistant Secretary of all the Pioneer Funds since September 2022; Private practice from 2017 – 2019.	None
Anthony J. Koenig, Jr. (60) Treasurer and Chief Financial and Accounting Officer	Since 2021. Serves at the discretion of the Board	Managing Director, Chief Operations Officer and Fund Treasurer of Amundi US since May 2021; Treasurer of all of the Pioneer Funds since May 2021; Assistant Treasurer of all of the Pioneer Funds from January 2021 to May 2021; and Chief of Staff, US Investment Management of Amundi US from May 2008 to January 2021	None
Luis I. Presutti (59) Assistant Treasurer	Since 2021. Serves at the discretion of the Board	Director – Fund Treasury of Amundi US since 1999; and Assistant Treasurer of all of the Pioneer Funds since 1999	None

90Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/24

---

---

Table of Contents

Name, Age and Position Held With the Fund	Term of Office and Length of Service	Principal Occupation(s) During At Least The Past Five Years	Other Directorships Held by Officer During At Least The Past Five Years
Gary Sullivan (66) Assistant Treasurer	Since 2021. Serves at the discretion of the Board	Senior Manager – Fund Treasury of Amundi US since 2012; and Assistant Treasurer of all of the Pioneer Funds since 2002	None
Antonio Furtado (42) Assistant Treasurer	Since 2021. Serves at the discretion of the Board	Fund Oversight Manager – Fund Treasury of Amundi US since 2020; Assistant Treasurer of all of the Pioneer Funds since 2020; and Senior Fund Treasury Analyst from 2012 - 2020	None
Michael Melnick (53) Assistant Treasurer	Since 2021. Serves at the discretion of the Board	Vice President - Deputy Fund Treasurer of Amundi US since May 2021; Assistant Treasurer of all of the Pioneer Funds since July 2021; Director of Regulatory Reporting of Amundi US from 2001 – 2021; and Director of Tax of Amundi US from 2000 - 2001	None
John Malone (53) Chief Compliance Officer	Since 2021. Serves at the discretion of the Board	Managing Director, Chief Compliance Officer of Amundi US Asset Management; Amundi Asset Management US, Inc.; and the Pioneer Funds since September 2018; Chief Compliance Officer of Amundi Distributor US, Inc. since January 2014.	None
Brandon Austin (52) Anti-Money Laundering Officer	Since 2022. Serves at the discretion of the Board	Director, Financial Security – Amundi Asset Management; Anti-Money Laundering Officer of all the Pioneer Funds since March 2022: Director of Financial Security of Amundi US since July 2021; Vice President, Head of BSA, AML and OFAC, Deputy Compliance Manager, Crédit Agricole Indosuez Wealth Management (investment management firm) (2013 – 2021)	None

Pioneer Municipal High Income Opportunities Fund, Inc. | Annual Report | 4/30/2491

---

---

Table of Contents

How to Contact Amundi

We are pleased to offer a variety of convenient ways for you to contact us for assistance or information.

You can call Equiniti Trust Company, LLC (EQ) for:

---

Account Information1-800-710-0935

Or write to EQ:

---

ForWrite to

General inquiries, lost dividend checks,Equiniti Trust
change of address, lost stock certificates,Company, LLC
stock transferOperations Center
6201 15th Ave.
Brooklyn, NY 11219

Dividend reinvestment plan (DRIP) Equiniti Trust
Company, LLC
Wall Street Station
P.O. Box 922
New York, NY 10269-0560

Website https://equiniti.com/us

For additional information, please contact your investment adviser or visit our web site www.amundi.com/us.

The Fund files a complete schedule of portfolio holdings with the Securities and Exchange Commission for the first and third quarters of each fiscal year as an exhibit to its reports on Form N-PORT. Stockholders may view the filed Form N-PORT by visiting the Commission’s web site at https://www.sec.gov.

---

---

Table of Contents

Amundi Asset Management US, Inc.
60 State Street
Boston, MA 02109

www.amundi.com/us

© 2024 Amundi Asset Management US, Inc. 33016-02-0624

ITEM 2. CODE OF ETHICS.

(a) Disclose whether, as of the end of the period covered by the report, the registrant has adopted a code of ethics that applies to the registrant’s principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions, regardless of whether these individuals are employed by the registrant or a third party. If the registrant has not adopted such a code of ethics, explain why it has not done so.

The registrant has adopted, as of the end of the period covered by this report, a code of ethics that applies to the registrant’s principal executive officer, principal financial officer, principal accounting officer and controller.

(b) For purposes of this Item, the term “code of ethics” means written standards that are reasonably designed to deter wrongdoing and to promote:

(1) Honest and ethical conduct, including the ethical handling of actual or apparent conflicts of interest between personal and professional relationships;

(2) Full, fair, accurate, timely, and understandable disclosure in reports and documents that a registrant files with, or submits to, the Commission and in other public communications made by the registrant;

(3) Compliance with applicable governmental laws, rules, and regulations;

(4) The prompt internal reporting of violations of the code to an appropriate person or persons identified in the code; and

(5) Accountability for adherence to the code.

(c) The registrant must briefly describe the nature of any amendment, during the period covered by the report, to a provision of its code of ethics that applies to the registrant’s principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions, regardless of whether these individuals are employed by the registrant or a third party, and that relates to any element of the code of ethics definition enumerated in paragraph (b) of this Item. The registrant must file a copy of any such amendment as an exhibit pursuant to Item 10(a), unless the registrant has elected to satisfy paragraph (f) of this Item by posting its code of ethics on its website pursuant to paragraph (f)(2) of this Item, or by undertaking to provide its code of ethics to any person without charge, upon request, pursuant to paragraph (f)(3) of this Item.

The registrant has made no amendments to the code of ethics during the period covered by this report.

(d) If the registrant has, during the period covered by the report, granted a waiver, including an implicit waiver, from a provision of the code of ethics to the registrant’s principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions, regardless of whether these individuals are employed by the registrant or a third party, that relates to one or more of the items set forth in paragraph (b) of this Item, the registrant must briefly describe the nature of the waiver, the name of the person to whom the waiver was granted, and the date of the waiver.

Not applicable.

(e) If the registrant intends to satisfy the disclosure requirement under paragraph (c) or (d) of this Item regarding an amendment to, or a waiver from, a provision of its code of ethics that applies to the registrant’s principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions and that relates to any element of the code of ethics definition enumerated in paragraph (b) of this Item by posting such information on its Internet website, disclose the registrant’s Internet address and such intention.

Not applicable.

(f) The registrant must:

(1) File with the Commission, pursuant to Item 12(a)(1), a copy of its code of ethics that applies to the registrant’s principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions, as an exhibit to its annual report on this Form N-CSR (see attachment);

(2) Post the text of such code of ethics on its Internet website and disclose, in its most recent report on this Form N-CSR, its Internet address and the fact that it has posted such code of ethics on its Internet website; or

(3) Undertake in its most recent report on this Form N-CSR to provide to any person without charge, upon request, a copy of such code of ethics and explain the manner in which such request may be made. See Item 10(2)

ITEM 3. AUDIT COMMITTEE FINANCIAL EXPERT.

(a) (1) Disclose that the registrant’s Board of Directors has determined that the registrant either:

(i) Has at least one audit committee financial expert serving on its audit committee; or

(ii) Does not have an audit committee financial expert serving on its audit committee.

The registrant’s Board of Directors has determined that the registrant has at least one audit committee financial expert.

(2) If the registrant provides the disclosure required by paragraph (a)(1)(i) of this Item, it must disclose the name of the audit committee financial expert and whether that person is “independent.” In order to be considered “independent” for purposes of this Item, a member of an audit committee may not, other than in his or her capacity as a member of the audit committee, the Board of Directors, or any other board committee:

(i) Accept directly or indirectly any consulting, advisory, or other compensatory fee from the issuer; or

(ii) Be an “interested person” of the investment company as defined in Section 2(a)(19) of the Act (15 U.S.C. 80a-2(a)(19)).

Mr. Fred J. Ricciardi, an independent Director, is such an audit committee financial expert.

(3) If the registrant provides the disclosure required by paragraph (a)(1) (ii) of this Item, it must explain why it does not have an audit committee financial expert.

Not applicable.

ITEM 4. PRINCIPAL ACCOUNTANT FEES AND SERVICES.

(a) Disclose, under the caption AUDIT FEES, the aggregate fees billed for each of the last two fiscal years for professional services rendered by the principal accountant for the audit of the registrant’s annual financial statements or services that are normally provided by the accountant in connection with statutory and regulatory filings or engagements for those fiscal years.

The audit fees for the Fund were $47,000 payable to Deloitte & Touche LLP for the year ended April 30, 2024 and $45,150 payable to Ernst & Young LLP for the year ended April 30, 2023.

(b) Disclose, under the caption AUDIT-RELATED FEES, the aggregate fees billed in each of the last two fiscal years for assurance and related services by the principal accountant that are reasonably related to the performance of the audit of the registrant’s financial statements and are not reported under paragraph (a) of this Item. Registrants shall describe the nature of the services comprising the fees disclosed under this category.

The audit-related services fees for the Fund were $0 payable to Deloitte & Touche LLP and $205 payable to Ernst & Young for the year ended April 30, 2024 and $1,640 payable to Ernst & Young LLP for the year ended April 30, 2023.

(c) Disclose, under the caption TAX FEES, the aggregate fees billed in each of the last two fiscal years for professional services rendered by the principal accountant for tax compliance, tax advice, and tax planning. Registrants shall describe the nature of the services comprising the fees disclosed under this category.

The Fund paid aggregate non-audit fees to Deloitte & Touche LLP for tax services of $10,500 and $10,105 to Ernst & Young LLP during the fiscal years ended April 30, 2024 and 2023, respectively.

(d) Disclose, under the caption ALL OTHER FEES, the aggregate fees billed in each of the last two fiscal years for products and services provided by the principal accountant, other than the services reported in paragraphs (a) through (c) of this Item. Registrants shall describe the nature of the services comprising the fees disclosed under this category.

There were no other fees in 2024 or 2023.

(e) (1) Disclose the audit committee’s pre-approval policies and procedures described in paragraph (c)(7) of Rule 2-01 of Regulation S-X.

PIONEER FUNDS

APPROVAL OF AUDIT, AUDIT-RELATED, TAX AND OTHER SERVICES

PROVIDED BY THE INDEPENDENT AUDITOR

SECTION I - POLICY PURPOSE AND APPLICABILITY

The Pioneer Funds recognize the importance of maintaining the independence of their outside auditors. Maintaining independence is a shared responsibility involving Amundi Asset Management US, Inc., the audit committee and the independent auditors.

The Funds recognize that a Fund’s independent auditors: 1) possess knowledge of the Funds, 2) are able to incorporate certain services into the scope of the audit, thereby avoiding redundant work, cost and disruption of Fund personnel and processes, and 3) have expertise that has value to the Funds. As a result, there are situations where it is desirable to use the Fund’s independent auditors for services in addition to the annual audit and where the potential for conflicts of interests are minimal. Consequently, this policy, which is intended to comply with Rule 210.2-01(C)(7), sets forth guidelines and procedures to be followed by the Funds when retaining the independent audit firm to perform audit, audit-related tax and other services under those circumstances, while also maintaining independence.

Approval of a service in accordance with this policy for a Fund shall also constitute approval for any other Fund whose pre-approval is required pursuant to Rule 210.2-01(c)(7)(ii).

In addition to the procedures set forth in this policy, any non-audit services that may be provided consistently with Rule 210.2-01 may be approved by the Audit Committee itself and any pre-approval that may be waived in accordance with Rule 210.2-01(c)(7)(i)(C) is hereby waived.

Selection of a Fund’s independent auditors and their compensation shall be determined by the Audit Committee and shall not be subject to this policy.

SECTION II - POLICY

SECTION III - POLICY DETAIL, CONTINUED

SECTION III - POLICY DETAIL, CONTINUED

SECTION III - POLICY DETAIL, CONTINUED

GENERAL AUDIT COMMITTEE APPROVAL POLICY:

(2) Disclose the percentage of services described in each of paragraphs (b) through (d) of this Item that were approved by the audit committee pursuant to paragraph (c)(7)(i)(C) of Rule 2-01 of Regulation S-X.

Non-Audit Services

Beginning with non-audit service contracts entered into on or after May 6, 2003, the effective date of the new SEC pre-approval rules, the Fund’s audit committee is required to pre-approve services to affiliates defined by SEC rules to the extent that the services are determined to have a direct impact on the operations or financial reporting of the Fund. For the years ended April 30, 2024 and 2023, there were no services provided to an affiliate that required the Fund’s audit committee pre-approval.

(f) If greater than 50 percent, disclose the percentage of hours expended on the principal accountants engagement to audit the registrant’s financial statements for the most recent fiscal year that were attributed to work performed by persons other than the principal accountant’s full-time, permanent employees.

N/A

(g) Disclose the aggregate non-audit fees billed by the registrants accountant for services rendered to the registrant, and rendered to the registrants investment adviser (not including any sub-adviser whose role is primarily portfolio management and is subcontracted with or overseen by another investment adviser), and any entity controlling, controlled by, or under common control with the adviser that provides ongoing services to the registrant for each of the last two fiscal years of the registrant.

The Fund paid aggregate non-audit fees to Deloitte & Touche LLP for tax services of $10,500 and $10,105 to Ernst & Young LLP during the fiscal years ended April 30, 2024 and 2023, respectively.

(h) Disclose whether the registrants audit committee of the Board of Directors has considered whether the provision of non-audit services that were rendered to the registrants investment adviser (not including any subadviser whose role is primarily portfolio management and is subcontracted with or overseen by another investment adviser), and any entity controlling, controlled by, or under common control with the investment adviser that provides ongoing services to the registrant that were not pre-approved pursuant to paragraph (c)(7)(ii) of Rule 2-01 of Regulation S-X is compatible with maintaining the principal accountant’s independence.

The Fund’s audit committee of the Board of Directors has considered whether the provision of non-audit services that were rendered to the Affiliates (as defined) that were not pre- approved pursuant to paragraph (c)(7)(ii) of Rule 2-01 of Regulation S-X is compatible with maintaining the principal accountant’s independence.

(i) A registrant identified by the Commission pursuant to Section 104(i)(2)(A) of the Sarbanes-Oxley Act of 2002 (15 U.S.C. 7214(i)(2)(A)), as having retained, for the preparation of the audit report on its financial statements included in the Form NCSR, a registered public accounting firm that has a branch or office that is located in a foreign jurisdiction and that the Public Company Accounting Oversight Board has determined it is unable to inspect or investigate completely because of a position taken by an authority in the foreign jurisdiction must electronically submit to the Commission on a supplemental basis documentation that establishes that the registrant is not owned or controlled by a governmental entity in the foreign jurisdiction. The registrant must submit this documentation on or before the due date for this form. A registrant that is owned or controlled by a foreign governmental entity is not required to submit such documentation.

N/A

(j) A registrant that is a foreign issuer, as defined in 17 CFR 240.3b-4, identified by the Commission pursuant to Section 104(i)(2)(A) of the Sarbanes-Oxley Act of 2002 (15 U.S.C. 7214(i)(2)(A)), as having retained, for the preparation of the audit report on its financial statements included in the Form N-CSR, a registered public accounting firm that has a branch or office that is located in a foreign jurisdiction and that the Public Company Accounting Oversight Board has determined it is unable to inspect or investigate completely because of a position taken by an authority in the foreign jurisdiction, for each year in which the registrant is so identified, must provide the below disclosures. Also, any such identified foreign issuer that uses a variable-interest entity or any similar structure that results in additional foreign entities being consolidated in the financial statements of the registrant is required to provide the below disclosures for itself and its consolidated foreign operating entity or entities. A registrant must disclose:

(1) That, for the immediately preceding annual financial statement period, a registered public accounting firm that the PCAOB was unable to inspect or investigate completely, because of a position taken by an authority in the foreign jurisdiction, issued an audit report for the registrant;

N/A

(2) The percentage of shares of the registrant owned by governmental entities in the foreign jurisdiction in which the registrant is incorporated or otherwise organized;

N/A

(3) Whether governmental entities in the applicable foreign jurisdiction with respect to that registered public accounting firm have a controlling financial interest with respect to the registrant;

N/A

(4) The name of each official of the Chinese Communist Party who is a member of the board of directors of the registrant or the operating entity with respect to the registrant;

N/A

(5) Whether the articles of incorporation of the registrant (or equivalent organizing document) contains any charter of the Chinese Communist Party, including the text of any such charter.

N/A

ITEM 5. AUDIT COMMITTEE OF LISTED REGISTRANTS

(a) If the registrant is a listed issuer as defined in Rule 10A-3 under the Exchange Act (17 CFR 240.10A-3), state whether or not the registrant has a separately-designated standing audit committee established in accordance with Section 3(a)(58)(A) of the Exchange Act (15 U.S.C. 78c(a)(58)(A)). If the registrant has such a committee, however designated, identify each committee member. If the entire Board of Directors is acting as the registrant’s audit committee as specified in Section 3(a)(58)(B) of the Exchange Act (15 U.S.C. 78c(a)(58)(B)), so state.

N/A

(b) If applicable, provide the disclosure required by Rule 10A-3(d) under the Exchange Act (17 CFR 240.10A-3(d)) regarding an exemption from the listing standards for audit committees.

N/A

ITEM 6. SCHEDULE OF INVESTMENTS.

File Schedule of Investments in securities of unaffiliated issuers as of the close of the reporting period as set forth in 210.1212 of Regulation S-X [17 CFR 210.12-12], unless the schedule is included as part of the report to shareholders filed under Item 1 of this Form.

Included in Item 1

ITEM 7. DISCLOSURE OF PROXY VOTING POLICIES AND PROCEDURES FOR CLOSED-END MANAGEMENT INVESTMENT COMPANIES.

A closed-end management investment company that is filing an annual report on this Form N-CSR must, unless it invests exclusively in non-voting securities, describe the policies and procedures that it uses to determine how to vote proxies relating to portfolio securities, including the procedures that the company uses when a vote presents a conflict between the interests of its shareholders, on the one hand, and those of the company’s investment adviser; principal underwriter; or any affiliated person (as defined in Section 2(a)(3) of the Investment Company Act of 1940 (15 U.S.C. 80a-2(a)(3)) and the rules thereunder) of the company, its investment adviser, or its principal underwriter, on the other. Include any policies and procedures of the company’s investment adviser, or any other third party, that the company uses, or that are used on the company’s behalf, to determine how to vote proxies relating to portfolio securities.

Proxy voting policies and procedures

Policy

Each of the Pioneer Funds and certain other clients of Amundi Asset Management US, Inc. (“Amundi US”) have delegated responsibility to vote proxies related to portfolio holdings to Amundi US. Amundi US is a fiduciary that owes each of its clients the duties of care and loyalty with respect to all services undertaken on the client’s behalf, including voting proxies for securities held by the client. When Amundi US has been delegated proxy-voting authority for a client, the duty of care requires Amundi US to monitor corporate events and to vote the proxies. To satisfy its duty of loyalty, Amundi US must place the client’s interests ahead of its own and must cast proxy votes in a manner consistent with the best interest of the client. It is Amundi US’s policy to vote proxies presented to Amundi US in a timely manner in accordance with these principles.

Amundi US’s sole concern in voting proxies is the economic effect of the proposal on the value of portfolio holdings, considering both the short- and long-term impact. In many instances, Amundi US believes that supporting the company’s strategy and voting “for” management’s proposals builds portfolio value. In other cases, however, proposals set forth by management may have a negative effect on that value, while some shareholder proposals may hold the best prospects for enhancing it. Amundi US monitors developments in the proxy voting arena and will revise this policy as needed.

Amundi US believes that environmental, social and governance (ESG) factors can affect companies’ long-term prospects for success and the sustainability of their business models. Since ESG factors that may affect corporate performance and economic value are considered by our investment professionals as part of the investment management process, Amundi US also considers these factors when reviewing proxy proposals. This approach is consistent with the stated investment objectives and policies of funds and investment strategies.

It should be noted that the proxy voting guidelines below are guidelines, not rules, and Amundi US reserves the right in all cases to vote contrary to guidelines where doing so is determined to represent the best economic interests of our clients. Further, the Pioneer Funds or other clients of Amundi US may direct Amundi US to vote contrary to guidelines.

Amundi US’s clients may request copies of their proxy voting records and of Amundi US’s proxy voting policies and procedures by either sending a written request to Amundi US’s Proxy Coordinator, or clients may review Amundi US’s proxy voting policies and procedures on-line at amundi.com/usinvestors. Amundi US may describe to clients its proxy voting policies and procedures by delivering a copy of Amundi US’s Form ADV (Part II), by separate notice to the client or by other means.

Applicability

This Proxy Voting policy and the procedures set forth below are designed to complement Amundi US’s investment policies and procedures regarding its general responsibility to monitor the performance and/or corporate events of companies that are issuers of securities held in accounts managed by Amundi US. This policy sets forth Amundi US’s position on a number of issues for which proxies may be solicited but it does not include all potential voting scenarios or proxy events. Furthermore, because of the special issues associated with proxy solicitations by closed-end Funds, Amundi US will vote shares of closed-end Funds on a case-by-case basis.

Purpose

The purpose of this policy is to ensure that proxies for United States (“US”) and non-US companies that are received in a timely manner will be voted in accordance with the principles stated above. Unless the Proxy Voting Oversight Group (as described below) specifically determines otherwise, all shares in a company held by Amundi US-managed accounts for which Amundi US has proxy-voting authority will be voted alike, unless a client has given specific voting instructions on an issue.

Amundi US does not delegate the authority to vote proxies relating to securities held by its clients to any of its affiliates. Any questions about this policy should be directed to Amundi US’s Chief of Staff, US Investment Management (the “Proxy Coordinator”).

Procedures

Proxy Voting Service

Amundi US has engaged an independent proxy voting service to assist in the voting of proxies. The proxy voting service works with custodians to ensure that all proxy materials are received by the custodians and are processed in a timely fashion. The proxy voting service votes all proxies in accordance with the proxy voting guidelines established by Amundi US and set forth herein, to the extent applicable. The proxy voting service will refer proxy questions to the Proxy Coordinator (described below) for instructions under circumstances where: (1) the application of the proxy voting guidelines is unclear; (2) a particular proxy question is not covered by the guidelines; or (3) the guidelines call for specific instructions on a case-by-case basis. The proxy voting service is also requested to call to the Proxy Coordinator’s attention specific proxy questions that, while governed by a guideline, appear to involve unusual or controversial issues. Amundi US reserves the right to attend a meeting in person and may do so when it determines that the company or the matters to be voted on at the meeting are strategically important to its clients.

To supplement its own research and analysis in determining how to vote on a particular proxy proposal, Amundi US may utilize research, analysis or recommendations provided by the proxy voting service on a case-by-case basis. Amundi US does not, as a policy, follow the assessments or recommendations provided by the proxy voting service without its own analysis and determination.

Proxy Coordinator

The Proxy Coordinator coordinates the voting, procedures and reporting of proxies on behalf of Amundi US’s clients. The Proxy Coordinator will deal directly with the proxy voting service and, in the case of proxy questions referred by the proxy voting service, will solicit voting recommendations and instructions from the Portfolio Management Group, or, to the extent applicable, investment sub-advisers. The Proxy Coordinator is responsible for ensuring that these questions and referrals are responded to in a timely fashion and for transmitting appropriate voting instructions to the proxy voting service. The Proxy Coordinator is responsible for verifying with the General Counsel or his or her designee whether Amundi US’s voting power is subject to any limitations or guidelines issued by the client (or in the case of an employee benefit plan, the plan’s director or other fiduciaries).

Referral Items

The proxy voting service will refer proxy questions to the Proxy Coordinator or his or her designee that are described by Amundi US’s proxy voting guidelines as to be voted on a case-by-case basis, that are not covered by Amundi US’s guidelines or where Amundi US’s guidelines may be unclear with respect to the matter to be voted on. Under such circumstances, the Proxy Coordinator will seek a written voting recommendation from the Chief Investment Officer, U.S. or his or her designated equity portfolio-management representative. Any such recommendation will include: (i) the manner in which the proxies should be voted; (ii) the rationale underlying any such decision; and (iii) the disclosure of any contacts or communications made between Amundi US and any outside parties concerning the proxy proposal prior to the time that the voting instructions are provided.

Securities Lending

In accordance with industry standards, proxies are not available to be voted when the shares are out on loan through either Amundi US’s lending program or a client’s managed security lending program. However, Amundi US will reserve the right to recall lent securities so that they may be voted according to Amundi US’s instructions. If a portfolio manager would like to vote a block of previously lent shares, the Proxy Coordinator will work with the portfolio manager and Investment Operations to recall the security, to the extent possible, to facilitate the vote on the entire block of shares. Certain clients participate in securities lending programs. Although such programs allow for the recall of securities for any reason, Amundi US may determine not to vote securities on loan and it may not always be possible for securities on loan to be recalled in time to be voted.

Share-Blocking

“Share-blocking” is a market practice whereby shares are sent to a custodian (which may be different than the account custodian) for record keeping and voting at the general meeting. The shares are unavailable for sale or delivery until the end of the blocking period (typically the day after general meeting date).

Amundi US will vote in those countries with “share-blocking.” In the event a manager would like to sell a security with “share-blocking”, the Proxy Coordinator will work with the Portfolio Manager and Investment Operations Department to recall the shares (as allowable within the market time-frame and practices) and/or communicate with executing brokerage firm. A list of countries with “share-blocking” is available from the Investment Operations Department upon request.

Proxy Voting Oversight Group

The members of the Proxy Voting Oversight Group include Amundi US’s Chief Investment Officer, U.S. or his or her designated equity portfolio management representative, the Chief of Staff, U.S., and the Chief Compliance Officer of the Adviser and Funds. Other members of Amundi US will be invited to attend meetings and otherwise participate as necessary. The Chief of Staff, U.S. will chair the Proxy Voting Oversight Group.

The Proxy Voting Oversight Group is responsible for developing, evaluating, and changing (when necessary) Amundi US’s proxy voting policies and procedures. The Group meets at least annually to evaluate and review this policy and the services of its third-party proxy voting service. In addition, the Proxy Voting Oversight Group will meet as necessary to vote on referral items and address other business as necessary.

Amendments

Amundi US may not amend this policy without the prior approval of the Proxy Voting Oversight Group.

Form N-PX

The Proxy Coordinator and the Director of Regulatory Reporting are responsible for ensuring that Form N-PX documents receive the proper review by a member of the Proxy Voting Oversight Group prior to a Fund officer signing the forms.

The Investment Operations department will provide the Compliance department with a copy of each Form N-PX filing prepared by the proxy voting service.

Compliance files N-PX. The Compliance department will ensure that a corresponding Form N-PX exists for each Amundi US registered investment company.

Following this review, each Form N-PX is formatted for public dissemination via the EDGAR system.

Prior to submission, each Form N-PX is to be presented to the Fund officer for a final review and signature.

Copies of the Form N-PX filings and their submission receipts are maintained according to Amundi US record keeping policies.

Proxy Voting Guidelines

Administrative

While administrative items appear infrequently in U.S. issuer proxies, they are quite common in non-U.S. proxies.

We will generally support these and similar management proposals:

Amundi US will vote on a case-by-case basis on other routine administrative items; however, Amundi US will oppose any routine proposal if insufficient information is presented in advance to allow Amundi US to judge the merit of the proposal. Amundi US has also instructed its proxy voting service to inform Amundi US of its analysis of any administrative items that may be inconsistent, in its view, with Amundi US’s goal of supporting the value of its clients’ portfolio holdings so that Amundi US may consider and vote on those items on a case-by-case basis in its discretion.

Auditors

We normally vote for proposals to:

Ratify the auditors. We will consider a vote against if we are concerned about the auditors’ independence or their past work for the company. Specifically, we will oppose the ratification of auditors and withhold votes for audit committee members if non-audit fees paid by the company to the auditing firm exceed the sum of audit fees plus audit-related fees plus permissible tax fees according to the disclosure categories proposed by the Securities and Exchange Commission.

We will normally oppose proposals that require companies to:

Board of Directors

On issues related to the board of directors, Amundi US normally supports management. We will, however, consider a vote against management in instances where corporate performance has been poor or where the board appears to lack independence.

General Board Issues

Amundi US will vote for:

We will vote against:

We will vote on a case-by case basis on these issues:

Elections of Directors

In uncontested elections of directors we will vote against:

We will also vote against:

We will vote on a case-by case basis on these issues:

Re-election of directors who have implemented or renewed a dead hand or modified dead-hand poison pill (a “dead-hand poison pill” is a shareholder rights plan that may be altered only by incumbent or “dead” directors. These plans prevent a potential acquirer from disabling a poison pill by obtaining control of the board through a proxy vote).

We will vote for:

Takeover-Related Measures

Amundi US is generally opposed to proposals that may discourage takeover attempts. We believe that the potential for a takeover helps ensure that corporate performance remains high.

Amundi US will vote for:

We will vote on a case-by-case basis on the following issues:

We will vote against:

Capital Structure

Managements need considerable flexibility in determining the company’s financial structure, and Amundi US normally supports managements’ proposals in this area. We will, however, reject proposals that impose high barriers to potential takeovers.

Amundi US will vote for:

We will vote on a case-by-case basis on the following issues:

We will vote against preemptive rights that we believe limit a company’s financing flexibility.

Compensation

Amundi US supports compensation plans that link pay to shareholder returns and believes that management has the best understanding of the level of compensation needed to attract and retain qualified people. At the same time, stock-related compensation plans have a significant economic impact and a direct effect on the balance sheet. Therefore, while we do not want to micromanage a company’s compensation programs, we place limits on the potential dilution these plans may impose.

Amundi US will vote for:

We will vote on a case-by-case basis on the following issues:

We will vote against:

We will vote on a case-by case basis on these issues:

Corporate Governance

Amundi US will vote for:

We will vote on a case-by-case basis on the following issues:

We will vote against:

Mergers and Restructurings

Amundi US will vote on the following and similar issues on a case-by-case basis:

We will normally vote against shareholder proposals requiring that the company be put up for sale.

Investment Companies

Many of our portfolios may invest in shares of closed-end funds or open-end funds (including exchange-traded funds). The non-corporate structure of these investments raises several unique proxy voting issues.

Amundi US will vote for:

Amundi US will vote on a case-by-case basis on:

In general, business development companies (BDCs) are not considered investment companies for these purposes but are treated as corporate issuers.

Environmental and Social Issues

Amundi US believes that environmental and social issues may influence corporate performance and economic return. Indeed, by analyzing all of a company’s risks and opportunities, Amundi US can better assess its intrinsic value and long-term economic prospects.

When evaluating proxy proposals relating to environmental or social issues, decisions are made on a case-by-case basis. We consider each of these proposals based on the impact to the company’s shareholders and economic return, the specific circumstances at each individual company, any potentially adverse economic concerns, and the current policies and practices of the company.

For example, shareholder proposals relating to environmental and social issues, and on which we will vote on a base-by-case basis, may include those seeking that a company:

In general, Amundi US believes these issues are important and should receive management attention.

Amundi US will support proposals where we believe the proposal, if implemented, would improve the prospects for the long-term success of the business and would provide value to the company and its shareholders. Amundi US may abstain on shareholder proposals with regard to environmental and social issues in cases where we believe the proposal, if implemented, would not be in the economic interests of the company, or where implementing the proposal would constrain management flexibility or would be unduly difficult, burdensome or costly.

When evaluating proxy proposals relating to environmental or social issues, Amundi US may consider the following factors or other factors deemed relevant, given such weight as deemed appropriate:

In the event of failures in risk management relating to environmental and social issues, Amundi US may vote against the election of directors responsible for overseeing these areas.

Amundi US will vote against proposals calling for substantial changes in the company’s business or activities. We will also normally vote against proposals with regard to contributions, believing that management should control the routine disbursement of funds.

Conflicts of interest

Amundi US recognizes that in certain circumstances a conflict of interest may arise when Amundi US votes a proxy.

A conflict of interest occurs when Amundi US’s interests interfere, or appear to interfere, with the interests of Amundi US’s clients.

A conflict may be actual or perceived and may exist, for example, when the matter to be voted on concerns:

Any member of the Proxy Voting Oversight Group and any other associate involved in the proxy voting process with knowledge of any apparent or actual conflict of interest must disclose such conflict to the Proxy Coordinator and the Chief Compliance Officer of Amundi US and the Funds. If any associate is lobbied or pressured with respect to any voting decision, whether within or outside of Amundi US, he or she should contact a member of the Proxy Voting Oversight Group or Amundi US’s Chief Compliance Officer.

The Proxy Voting Oversight Group will review each item referred to Amundi US by the proxy voting service to determine whether an actual or potential conflict of interest exists in connection with the proposal(s) to be voted upon. The review will be conducted by comparing the apparent parties affected by the proxy proposal being voted upon against the Controller’s and Compliance Department’s internal list of interested persons and, for any matches found, evaluating the anticipated magnitude and possible probability of any conflict of interest being present. The Proxy Voting Oversight Group may cause any of the following actions to be taken when a conflict of interest is present:

If the Proxy Voting Oversight Group perceives a material conflict of interest, the Group may also choose to disclose the conflict to the affected clients and solicit their consent to proceed with the vote or their direction (including through a client’s fiduciary or other adviser), or may take such other action in good faith (in consultation with counsel) that would protect the interests of clients.

For each referral item, the determination regarding the presence or absence of any actual or potential conflict of interest will be documented in a Conflicts of Interest Report prepared by the Proxy Coordinator.

The Proxy Voting Oversight Group will review periodically the independence of the proxy voting service. This may include a review of the service’s conflict management procedures and other documentation and an evaluation as to whether the service continues to have the competency and capacity to vote proxies.

Decisions Not to Vote Proxies

Although it is Amundi US’s general policy to vote all proxies in accordance with the principles set forth in this policy, there may be situations in which the Proxy Voting Oversight Group does not vote a proxy referred to it. For example, because of the potential conflict of interest inherent in voting shares of a Credit Agricole Affiliate, Amundi US will abstain from voting the shares unless otherwise directed by a client. In such a case, the Proxy Coordinator will inform Amundi Compliance before exercising voting rights.

There exist other situations in which the Proxy Voting Oversight Group may refrain from voting a proxy. For example, if the cost of voting a foreign security outweighs the benefit of voting, the Group may not vote the proxy. The Group may not be given enough time to process a vote, perhaps because it receives a meeting notice too late or it cannot obtain a translation of the agenda in the time available. If Amundi US has outstanding “sell” orders, the proxies for shares subject to the order may not be voted to facilitate the sale. Although Amundi US may hold shares on a company’s record date, if the shares are sold prior to the meeting date the Group may decide not to vote those shares.

Supervision

Escalation

It is each associate’s responsibility to contact his or her business unit head, the Proxy Coordinator, a member of the Proxy Voting Oversight Group or Amundi US’s Chief Compliance Officer if he or she becomes aware of any possible noncompliance with this policy.

Training

Amundi US will conduct periodic training regarding proxy voting and this policy. It is the responsibility of the business line policy owner and the applicable Compliance Department to coordinate and conduct such training.

Related policies and procedures

Amundi US’s Books and Records Policy and the Books and Records of the Pioneer Funds’ Policy.

Record Keeping

The Proxy Coordinator shall ensure that Amundi US’s proxy voting service:

The Proxy Coordinator shall ensure that for those votes that may require additional documentation (i.e. conflicts of interest, exception votes and case-by-case votes) the following records are maintained:

Amundi US shall maintain the above records in the client’s file in accordance with applicable regulations.

Related regulations

Form N-1A, Form N-PX, ICA Rule 30b1-4, Rule 31a1-3, Rule 38a-1 and IAA 206(4) -6, Rule 204 -2

Adopted by the Pioneer Funds’ Boards of Directors

October 5, 2004

Effective Date:

October 5, 2004

Revision Dates:

September 2009, December 2015, August 2017, February 2019, and January 2021

ITEM 8. PORTFOLIO MANAGERS OF CLOSED-END MANAGEMENT INVESTMENT COMPANIES.

(a) If the registrant is a closed-end management investment company that is filing an annual report on this Form N-CSR, provide the following information:

(1) State the name, title, and length of service of the person or persons employed by or associated with the registrant or an investment adviser of the registrant who are primarily responsible for the day-to-day management of the registrant’s portfolio (“Portfolio Manager”). Also state each Portfolio Manager’s business experience during the past 5 years.

Additional information about the portfolio managers

Other accounts managed by the portfolio managers

The table below indicates, for the portfolio managers of the fund, information about the accounts other than the fund over which the portfolio manager has day-to-day investment responsibility. All information on the number of accounts and total assets in the table is as of April 30, 2024. For purposes of the table, “Other Pooled Investment Vehicles” may include investment partnerships, undertakings for collective investments in transferable securities (“UCITS”) and other non-U.S. investment funds and group trusts, and “Other Accounts” may include separate accounts for institutions or individuals, insurance company general or separate accounts, pension funds and other similar institutional accounts but generally do not include the portfolio manager’s personal investment accounts or those which the manager may be deemed to own beneficially under the code of ethics. Certain funds and other accounts managed by the portfolio manager may have substantially similar investment strategies.

Potential conflicts of interest

When a portfolio manager is responsible for the management of more than one account, the potential arises for the portfolio manager to favor one account over another. The principal types of potential conflicts of interest that may arise are discussed below. For the reasons outlined below, Amundi US does not believe that any material conflicts are likely to arise out of a portfolio manager’s responsibility for the management of the fund as well as one or more other accounts. Although Amundi US has adopted procedures that it believes are reasonably designed to detect and prevent violations of the federal securities laws and to mitigate the potential for conflicts of interest to affect its portfolio management decisions, there can be no assurance that all conflicts will be identified or that all procedures will be effective in mitigating the potential for such risks. Generally, the risks of such conflicts of interest are increased to the extent that a portfolio manager has a financial incentive to favor one account over another. Amundi US has structured its compensation arrangements in a manner that is intended to limit such potential for conflicts of interest. See “Compensation of Portfolio Managers” below.

Compensation of portfolio managers

Amundi US has adopted a system of compensation for portfolio managers that seeks to align the financial interests of the portfolio managers with those of shareholders of the accounts (including Pioneer funds) the portfolio managers manage, as well as with the financial performance of Amundi US. The compensation program for all Amundi US portfolio managers includes a base salary (determined by the rank and tenure

of the employee) and an annual bonus program, as well as customary benefits that are offered generally to all full-time employees. Base compensation is fixed and normally reevaluated on an annual basis. Amundi US seeks to set base compensation at market rates, taking into account the experience and responsibilities of the portfolio manager. The bonus plan is intended to provide a competitive level of annual bonus compensation that is tied to the portfolio manager achieving superior investment performance and align the interests of the investment professional with those of shareholders, as well as with the financial performance of Amundi US. Any bonus under the plan is completely discretionary, with a maximum annual bonus that may be in excess of base salary. The annual bonus is based upon a combination of the following factors:

The quantitative and qualitative performance components comprise 80% and 20%, respectively, of the overall bonus calculation (on a pre-adjustment basis). A portion of the annual bonus is deferred for a specified period and may be invested in one or more Pioneer funds.

Certain portfolio managers participate in other programs designed to reward and retain key contributors. Portfolio managers also may participate in a deferred compensation program, whereby deferred amounts are invested in one or more Pioneer funds or collective investment trusts or other unregistered funds with similar investment objectives, strategies and policies.

Share ownership by portfolio managers

The following table indicates as of April 30, 2024 the value, within the indicated range, of shares beneficially owned by the portfolio managers of the fund.

ITEM 9. PURCHASES OF EQUITY SECURITIES BY CLOSED-END MANAGEMENT INVESTMENT COMPANY AND AFFILIATED PURCHASERS.

(a) If the registrant is a closed-end management investment company, in the following tabular format, provide the information specified in paragraph (b) of this Item with respect to any purchase made by or on behalf of the registrant or any affiliated purchaser, as defined in Rule 10b-18(a)(3) under the Exchange Act (17 CFR 240.10b-18(a)(3)), of shares or other units of any class of the registrant’s equity securities that is registered by the registrant pursuant to Section 12 of the Exchange Act (15 U.S.C. 781).

During the period covered by this report, there were no purchases made by or on behalf of the registrant or any affiliated purchaser as defined in Rule 10b-18(a)(3) under the Securities Exchange Act of 1934 (the Exchange Act), of shares of the registrants equity securities that are registered by the registrant pursuant to Section 12 of the Exchange Act.

ITEM 10. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS.

Describe any material changes to the procedures by which shareholders may recommend nominees to the registrant’s Board of Directors, where those changes were implemented after the registrant last provided disclosure in response to the requirements of Item 407(c)(2)(iv) of Regulation S-R(17 CFR 229.407)(as required by Item 22(b)(15)) of Schedule 14A (17 CFR 240.14a-101), or this Item.

There have been no material changes to the procedures by which the shareholders may recommend nominees to the registrant’s Board of Directors since the registrant last provided disclosure in response to the requirements of Item 407(c)(2)(iv) of Regulation S-R of Schedule 14(A) in its definitive proxy statement, or this item.

ITEM 11. CONTROLS AND PROCEDURES.

(a) Disclose the conclusions of the registrant’s principal executive and principal financials officers, or persons performing similar functions, regarding the effectiveness of the registrant’s disclosure controls and procedures (as defined in Rule 30a-3(c) under the Act (17 CFR 270.30a-3(c))) as of a date within 90 days of the filing date of the report that includes the disclosure required by this paragraph, based on the evaluation of these controls and procedures required by Rule 30a-3(b) under the Act (17 CFR 270.30(a)-3(b) and Rules 13a-15(b) or 15d-15(b) under the Exchange Act (17 CFR 240.13a-15(b) or 240.15d-15(b)).

The registrant’s principal executive officer and principal financial officer have concluded that the registrant’s disclosure controls and procedures are effective based on the evaluation of these controls and procedures as of a date within 90 days of the filing date of this report.

(b) Disclose any change in the registrant’s internal control over financial reporting (as defined in Rule 30a-3(d) under the Act (17CFR 270.30a-3(d)) that occurred during the period covered by this report that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting.

There were no significant changes in the registrant’s internal control over financial reporting that occurred during the period covered by this report that have materially affected, or are reasonably likely to materially affect, the registrant’s internal control over financial reporting.

Item 12. Disclosure of Securities Lending Activities for Closed-End Management Investment Companies.

(a) If the registrant is a closed-end management investment company, provide the following dollar amounts of income and compensation related to the securities lending activities of the registrant during its most recent fiscal year:

N/A

(1) Gross income from securities lending activities;

N/A

(2) All fees and/or compensation for each of the following securities lending activities and related services: any share of revenue generated by the securities lending program paid to the securities lending agent(s) (revenue split); fees paid for cash collateral management services (including fees deducted from a pooled cash collateral reinvestment vehicle) that are not included in the revenue split; administrative fees that are not included in the revenue split; fees for indemnification that are not included in the revenue split; rebates paid to borrowers; and any other fees relating to the securities lending program that are not included in the revenue split, including a description of those other fees;

N/A

(3) The aggregate fees/compensation disclosed pursuant to paragraph (2); and

N/A

(4) Net income from securities lending activities (i.e., the dollar amount in paragraph (1) minus the dollar amount in paragraph (3)).

If a fee for a service is included in the revenue split, state that the fee is included in the revenue split.

N/A

(b) If the registrant is a closed-end management investment company, describe the services provided to the registrant by the securities lending agent in the registrants most recent fiscal year.

N/A

ITEM 13. EXHIBITS.

(a) File the exhibits listed below as part of this Form. Letter or number the exhibits in the sequence indicated.

(1) Any code of ethics, or amendment thereto, that is the subject of the disclosure required by Item 2, to the extent that the registrant intends to satisfy the Item 2 requirements through filing of an exhibit.

(2) A separate certification for each principal executive officer and principal financial officer of the registrant as required by Rule 30a-2(a) under the Act (17 CFR 270.30a-2(a)) , exactly as set forth below: Filed herewith.

(b) Certifications pursuant to Rule 30a-2(b) under the 1940 Act and Section 906 of the Sarbanes-Oxley Act of 2002 are attached hereto.

(3) Not applicable.

(4) Registrant’s Independent Public Accountant, attached as Exhibit 99.ACCT.

SIGNATURES

[See General Instruction F]

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

(Registrant) Pioneer Municipal High Income Opportunities Fund, Inc.

By (Signature and Title)* /s/ Lisa M. Jones

Lisa M. Jones, Principal Executive Officer

Date July 8, 2024

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

By (Signature and Title)* /s/ Lisa M. Jones

Lisa M. Jones, Principal Executive Officer

Date July 8, 2024

By (Signature and Title)* /s/ Anthony J. Koenig, Jr.

Anthony J. Koenig, Jr., Principal Financial Officer

Date July 8, 2024