Amendment: SEC Form SCHEDULE 13D/A filed by Xtant Medical Holdings Inc.

601 Lexington Avenue, 54th Floor, New York, New York 10022.

OrbiMed Advisors, a limited liability company organized under the laws of Delaware and a registered investment adviser under the Investment Advisers Act of 1940, as amended. OrbiMed ROF, a limited liability company organized under the laws of Delaware. Carl L. Gordon is a member of OrbiMed Advisors. Sven H. Borho is a member of OrbiMed Advisors. W. Carter Neild is a member of OrbiMed Advisors. Geoffrey C. Hsu is a member of OrbiMed Advisors. C. Scotland Stevens is a member of OrbiMed Advisors. David P. Bonita is a member of OrbiMed Advisors. Peter A. Thompson is a member of OrbiMed Advisors. Matthew S. Rizzo is a member of OrbiMed Advisors. Trey Block is the Chief Financial Officer of OrbiMed Advisors.

Not applicable.

Not applicable.

Item 2(a) is incorporated herein by reference.

Not applicable.

The Reporting Persons from time to time intend to review their investment in the Issuer on the basis of various factors, including the Issuer's business, financial condition, results of operations and prospects, general economic and industry conditions, the securities markets in general and those for the Issuer's Shares in particular, as well as other developments and other investment opportunities. Based upon such review, the Reporting Persons will take such actions in the future as the Reporting Persons may deem appropriate in light of the circumstances existing from time to time. If the Reporting Persons believe that further investment in the Issuer is attractive, whether because of the market price of Shares or otherwise, they may acquire Shares or other securities of the Issuer either in the open market or in privately negotiated transactions. Except as set forth in this Amendment No. 13, the Reporting Persons have not formulated any plans or proposals which relate to or would result in: (a) the acquisition by any person of additional securities of the Issuer or the disposition of securities of the Issuer, (b) an extraordinary corporate transaction, such as a merger, reorganization or liquidation, involving the Issuer or any of its subsidiaries, (c) a sale or transfer of a material amount of the assets of the Issuer or any of its subsidiaries, (d) any change in the present Board of Directors or management of the Issuer, including any plans or proposals to change the number or term of directors or to fill any existing vacancies on the Board of Directors, (e) any material change in the Issuer's capitalization or dividend policy of the Issuer, (f) any other material change in the Issuer's business or corporate structure, (g) any change in the Issuer's charter or bylaws or other instrument corresponding thereto or other action which may impede the acquisition of control of the Issuer by any person, (h) causing a class of the Issuer's securities to be deregistered or delisted from a national securities exchange or to cease to be authorized to be quoted in an inter-dealer quotation system of a registered national securities association, (i) a class of equity securities of the Issuer becoming eligible for termination of registration pursuant to Section 12(g)(4) of the Act or (j) any action similar to any of those enumerated above.

The following disclosure is based upon 139,067,915 Shares outstanding of the Issuer as set forth in the Issuer's Annual Report on Form 10-K, filed with the SEC on March 6, 2025. As of the date of this filing, ROS Acquisition Offshore LP ("ROS Acquisition"), a Cayman Islands exempted limited partnership, holds 0 Shares, constituting approximately 0.0% of the issued and outstanding Shares. OrbiMed Advisors, pursuant to its authority as the investment manager of ROS Acquisition, has the power to direct the vote and to direct the disposition of the Shares held by ROS Acquisition. As a result, OrbiMed Advisors may be deemed to indirectly beneficially own the Shares held by ROS Acquisition. OrbiMed Advisors exercises this investment and voting power through a management committee comprised of Carl L. Gordon, Sven H. Borho, and W. Carter Neild, each of whom disclaims beneficial ownership of the Shares held by ROS Acquisition. In addition, OrbiMed Advisors, pursuant to its authority as investment manager of ROS Acquisition, caused ROS Acquisition to enter into the agreements referred to in Item 6 below. As of the date of this filing, OrbiMed Royalty Opportunities II, LP ("ORO II"), a limited partnership organized under the laws of Delaware, holds 0 Shares, constituting approximately 0.0% of the issued and outstanding Shares. OrbiMed ROF is the general partner of ORO II, pursuant to the terms of the limited partnership agreement of ORO II, and OrbiMed Advisors is the managing member of OrbiMed ROF, pursuant to the terms of the limited liability company agreement of OrbiMed ROF. As a result, OrbiMed Advisors and OrbiMed ROF share power to direct the vote and disposition of the Shares held by ORO II and may be deemed directly or indirectly, including by reason of their mutual affiliation, to be the beneficial owners of the Shares held by ORO II. OrbiMed Advisors exercises this investment and voting power through a management committee comprised of Carl L. Gordon, Sven H. Borho, and W. Carter Neild, each of whom disclaims beneficial ownership of the Shares held by ORO II. In addition, OrbiMed Advisors, pursuant to its authority under the limited liability company agreement of OrbiMed ROF, and OrbiMed ROF, pursuant to its authority under the limited partnership agreement of ORO II, caused ORO II to enter into the agreements referred to in Item 6 below.

Item 5(a) is incorporated by reference herein.

On April 10, 2025, ROS Acquisition sold 56,004,974 Shares at $0.42 per Share. On April 10, 2025, ORO II sold 17,109,618 Shares at $0.42 per Share.

Not applicable.

As of April 10, 2025, the Reporting Persons are believed to have ceased to be the beneficial owners of more than five percent of the outstanding Shares.

OrbiMed ROF is the general partner of ORO II, pursuant to the terms of the limited partnership agreement of ORO II. Pursuant to this agreement and relationship, OrbiMed ROF has discretionary investment management authority with respect to the assets of ORO II. Such authority includes the power to vote and otherwise dispose of securities held by ORO II. The number of outstanding Shares of the Issuer attributable to ORO II is 0. OrbiMed ROF, pursuant to its authority under the limited partnership agreement of ORO II, may be considered to hold indirectly 0 Shares. OrbiMed Advisors is the managing member of OrbiMed ROF pursuant to the terms of the limited liability company agreement of OrbiMed ROF and is the investment manager of ROS Acquisition. Pursuant to these relationships, OrbiMed Advisors has discretionary investment management authority with respect to the assets of ROS Acquisition and, together with OrbiMed ROF, ORO II. Such authority includes the power of OrbiMed Advisors to vote and otherwise dispose of securities held by ROS Acquisition and ORO II. The aggregate number of fully diluted Shares held by ROS Acquisition is 0 and the aggregate number of fully diluted shares owned by ORO II is 0. OrbiMed Advisors may be considered to hold indirectly 0 Shares.

----------------------------------------------------------------------------------------------------------------------------- Exhibit Description ----------------------------------------------------------------------------------------------------------------------------- 1. Joint Filing Agreement among OrbiMed Advisors LLC and OrbiMed ROF II LLC. -----------------------------------------------------------------------------------------------------------------------------