X0306 4 2022-08-15 0 0001453593 Xtant Medical Holdings, Inc. XTNT 0001055951 ORBIMED ADVISORS LLC 601 LEXINGTON AVENUE 54TH FLOOR NEW YORK NY 10022 1 0 1 0 0001767936 Orbimed ROF II LLC 601 LEXINGTON AVE., 54TH FLOOR NEW YORK NY 10022 1 0 1 0 Common Stock, $0.000001 par value 2022-08-15 4 J 0 215415 0 A 215415 I See Footnotes Common Stock, $0.000001 par value 2022-08-15 4 J 0 215415 0 A 215415 I See Footnotes This restricted stock unit award was granted to Michael Eggenberg ("Eggenberg"), a director of Xtant Medical Holdings, Inc. ("Xtant"). These shares are subject to restricted stock unit awards granted under the Xtant Medical Holdings, Inc. Amended and Restated 2018 Equity Incentive Plan, and vest and become issuable on August 23, 2023, conditioned upon each of Eggenberg and Matthew Rizzo ("Rizzo") remaining a director of Xtant through the vesting date. See Exhibit 99.1. This report on Form 4 is jointly filed by OrbiMed Advisors and ROF II. Each of OrbiMed Advisors and ROF II disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. OrbiMed Advisors has designated certain representatives, including Rizzo and Eggenberg, to serve on Xtant's board of directors. This report shall not be deemed an admission that any such entity is a beneficial owner of such securities for the purpose of Section 16 of the Exchange Act or for any other purposes. This restricted stock unit award was granted to Rizzo, a director of Xtant. /s/ Sven H. Borho, Member of OrbiMed Advisors LLC 2022-08-17 /s/ Sven H. Borho, Member of OrbiMed ROF II LLC 2022-08-17 /s/ Carl L. Gordon, Member of OrbiMed Advisors LLC 2022-08-17 /s/ Carl L. Gordon, Member of OrbiMed ROF II LLC 2022-08-17 /s/ W. Carter Neild, Member of OrbiMed Advisors LLC 2022-08-17 /s/ W. Carter Neild, Member of OrbiMed ROF II LLC 2022-08-17