SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person* Sidow Kevin (Last) (First) (Middle) C/O CARLSMED, INC. 1800 ASTON AVE., SUITE 100 (Street) CARLSBAD CA 92008 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 07/22/2025	3. Issuer Name and Ticker or Trading Symbol CARLSMED, INC. [ CARL ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director 10% Owner Officer (give title below) Other (specify below)	5. If Amendment, Date of 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

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Series B Preferred Stock	(1)	(1)	Common Stock	28,900	(1)	D
Stock Option (Right to Buy)	(3)	01/07/2031	Common Stock	51,638(2)(3)	$0.33(6)	D
Stock Option (Right to Buy)	(4)	05/06/2034	Common Stock	44,802(2)(4)	$2.12(6)	D
Stock Option (Right to Buy)	(5)	04/09/2035	Common Stock	7,196(2)(5)	$5.91(6)	D

Explanation of Responses:

1. Includes 28,900 shares of Series B Preferred Stock issued to the Reporting Person on April 18, 2022. Each share of Series B 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 after giving effect to the 1-to-5.58 reverse split of the Issuer's common and preferred stock, effected on July 10, 2025 (the "Reverse Split"). These shares are reported on an as-converted 1-to-1 basis and have no expiration date.

2. These options are reported after giving effect to the Reverse Split of the Issuer's common stock.

3. Includes 51,638 fully vested and exercisable options convertible into approximately 51,638 shares of the Issuer's common stock.

4. Includes 13,067 fully vested and exercisable options convertible into approximately 13,067 shares of the Issuer's common stock, and 31,735 unvested stock options convertible into approximately 31,735 shares of the Issuer's common stock. These options began to vest on May 1, 2024, subject to a one-year cliff, and will be fully vested on May 1, 2028.

5. Includes 7,196 unvested stock options convertible into approximately 7,196 shares of the Issuer's common stock which began to vest on December 31, 2024, subject to a one-year cliff, and will be fully vested on December 31, 2028.

6. The exercise price has been adjusted to reflect the Reverse Split.

	/s/ Leonard Greenstein, as attorney-in-fact for Kevin Sidow	07/22/2025
	** Signature of Reporting Person	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 5 (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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