TERRESTRIAL ENERGY INC.

TERRESTRIAL ENERGY INC._May 5, 2026

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): May 5, 2026

TERRESTRIAL ENERGY INC.

(Exact name of registrant as specified in its charter)


Delaware		001-42252		98-1785406
(State or other jurisdiction of incorporation)		(Commission File Number)		(IRS Employer Identification No.)

2730 W. Tyvola Road, Suite 100

Charlotte, NC 28217

(Address of principal executive offices, including zip code)

Registrant’s telephone number, including area code: (646) 687-8212

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act

Title of each class	Trading Symbol(s)	Name of each exchange on which registered
Common Stock, par value $0.0001 per share	IMSR	The Nasdaq Stock Market LLC
Redeemable Warrants, each whole warrant exercisable for one Common Stock at a price of $11.50 per share	IMSRW	The Nasdaq Stock Market LLC

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

On May 5, 2026, David Hill informed Terrestrial Energy Inc. (the “Company”) that he was resigning from the Company’s Board of Directors (the “Board”), effective July 1, 2026. Mr. Hill joined the Board in 2014 and his decision to resign from the Board is not the result of any disagreement on any matter relating to the Company’s operations, policies or practices.

SIGNATURES

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


Date: May 8, 2026	TERRESTRIAL ENERGY INC.

	By:	/s/ Brian Thrasher
	Name:	Brian Thrasher
	Title:	Chief Financial Officer

Terrestrial Energy Inc. filed SEC Form 8-K: Leadership Update