Sec Form 3 Filing - ROOT JONATHAN D @ CARLSMED, INC. - 2025-07-22

FORM 3 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 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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1. Name and Address of Reporting Person ROOT JONATHAN D 2. Issuer Name and Ticker or Trading Symbol CARLSMED, INC. [ CARL] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O CARLSMED, INC., 1800 ASTON AVE., SUITE 100 3. Date of Earliest Transaction (MM/DD/YY) 07/22/2025 (Street) CARLSBAD, CA92008 4. If Amendment, Date Original Filed (MM/DD/YY) 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 (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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

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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 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 Series A Preferred Stock ( 5 ) ( 5 ) ( 5 ) Common Stock 2,948,794 I See Footnotes ( 1 ) ( 4 ) Series B Preferred Stock ( 5 ) ( 5 ) ( 5 ) Common Stock 825,135 I See Footnotes ( 1 ) ( 4 ) Series C Preferred Stock ( 5 ) ( 5 ) ( 5 ) Common Stock 531,877 I See Footnotes ( 1 ) ( 4 ) Series A Preferred Stock ( 5 ) ( 5 ) ( 5 ) Common Stock 149,655 I See Footnotes ( 2 ) ( 4 ) Series B Preferred Stock ( 5 ) ( 5 ) ( 5 ) Common Stock 41,876 I See Footnotes ( 2 ) ( 4 ) Series C Preferred Stock ( 5 ) ( 5 ) ( 5 ) Common Stock 26,993 I See Footnotes ( 2 ) ( 4 ) Series C Preferred Stock ( 5 ) ( 5 ) ( 5 ) Common Stock 1,117,743 I See Footnotes ( 3 ) ( 4 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other ROOT JONATHAN D C/O CARLSMED, INC. 1800 ASTON AVE., SUITE 100 CARLSBAD, CA92008 X Signatures /s/ Leonard Greenstein, as attorney-in-fact for Jonathan Root 07/22/2025 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Stock held by U.S. Venture Partners XII, L.P. ("USVP XII"). ( 2 )Stock held by U.S. Venture Partners XII-A, L.P. ("USVP XII-A"). ( 3 )Stock held by U.S. Venture Partners Select Fund I, L.P. ("USVP SFI"), on its own behalf and as nominee for U.S. Venture Partners Select Fund I-A, L.P. ("USVP SFI-A"). ( 4 )Presidio Management Group XII, L.L.C ("PMG XII") is the general partner of USVP XII and USVP XII-A. Presidio Management Group Select Fund I, L.L.C ("PMG SFI," and, together with USVP XII, USVP XII-A, USVP SFI, USVP SFI-A, and PMG XII, "USVP") is the general partner of USVP SFI and USVP SFI-A. The Reporting Person is a managing member of PMG XII and PMG SFI and may be deemed to share voting and dispositive power over the stock held by USVP. The Reporting Person disclaims beneficial ownership of such stock, except to the extent of any pecuniary interest therein. ( 5 )These shares of preferred stock are reported after giving effect to the 1-for-5.58 reverse split of the Issuer's common and preferred stock effected on July 10, 2025 (the "Reverse Split"). Each share of Series A Preferred Stock, Series B Preferred Stock, and Series C Preferred Stock is convertible into one share of the Issuer's common stock immediately prior to the closing of the Issuer's initial public offering. These shares are reported in Table II above on an as-converted 1-to-1 basis and have no expiration date.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* 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).

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