Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
ORBIMED ADVISORS LLC
   2. Issuer Name and Ticker or Trading Symbol
Xtant Medical Holdings, Inc. [XTNT] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
601 LEXINGTON AVENUE, 54TH FLOOR		 3. Date of Earliest Transaction (Month/Day/Year)
09/17/2018
(Street)

NEW YORK, NY 10022		 4. If Amendment, Date Original Filed(Month/Day/Year)
 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)		 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)		 4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)		 5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)		 6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)		 7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)		 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)		 5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)		 6. Date Exercisable and Expiration Date
(Month/Day/Year)		 7. Title and Amount of Underlying Securities
(Instr. 3 and 4)		 8. Price of Derivative Security
(Instr. 5)		 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)		 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)		 11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Warrant (right to buy) $ 0.01 09/17/2018   A(4)   765,992   09/17/2018 08/01/2028 Common Stock 765,992 $ 0 765,992 I See Footnotes (1) (3)
Warrant (right to buy) $ 0.01 09/17/2018   A(4)   434,008   09/17/2018 08/01/2028 Common Stock 434,008 $ 0 434,008 I See Footnotes (2) (3)

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
ORBIMED ADVISORS LLC
601 LEXINGTON AVENUE
54TH FLOOR
NEW YORK, NY 10022		   X   X    

Signatures

 /s/ Sven H. Borho, Member of OrbiMed Advisors LLC   09/19/2018
**Signature of Reporting Person Date
 /s/ Carl L. Gordon, Member of OrbiMed Advisors LLC   09/19/2018
**Signature of Reporting Person Date
 /s/ Jonathan T. Silverstein, Member of OrbiMed Advisors LLC   09/19/2018
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) These securities are held of record by ROS Acquisition Offshore LP ("ROS Acquisition"). OrbiMed Advisors LLC ("Advisors"), a registered adviser under the Investment Advisors Act of 1940, as amended, is the investment manager of ROS Acquisition. Advisors is also the investment manager of Royalty Opportunities S.a r.l., of which ROS Acquisition is a wholly-owned subsidiary. By virtue of such relationships, Advisors may be deemed to have voting and investment power with respect to the securities held by ROS Acquisition noted above and as a result may be deemed to have beneficial ownership over such securities. Advisors exercised this investment and voting power through a management committee comprised of Carl L. Gordon, Sven H. Borho and Jonathan T. Silverstein, each of whom disclaims beneficial ownership of the securities held by ROS Acquisition.
(2) These securities are held of record by OrbiMed Royalty Opportunities II, LP ("ORO II"). OrbiMed ROF II LLC ("ROF II") is the sole general partner of ORO II, and Advisors is the sole managing member of ROF II. By virtue of such relationships, Advisors may be deemed to have voting and investment power with respect to the securities held by ORO II noted above and as a result may be deemed to have beneficial ownership over such securities. Advisors exercised this investment and voting power through a management committee comprised of Carl L. Gordon, Sven H. Borho and Jonathan T. Silverstein, each of whom disclaims beneficial ownership of the securities held by ORO II.
(3) Each of ROS Acquisition, ORO II and the reporting person 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. This report shall not be deemed an admission that any such entity or the reporting person is a beneficial owner of such securities for the purposes of Section 16 of the Exchange Act, or for any other purposes.
(4) This warrant was acquired from Xtant Medical Holdings, Inc. in connection with and as a condition to the effectiveness of that certain Twenty-Fifth Amendment to the Amended and Restated Credit Agreement, effective as of August 1, 2018.

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