SEC FORM 4

SEC FORM 4SEC Form 4

FORM 4

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
or Section 30(h) of the Investment Company Act of 1940

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

MARIANI PETER J

(Last)

(First)

(Middle)

C/O CYTOSORBENTS CORPORATION

305 COLLEGE ROAD EAST

(Street)

PRINCETON

NEW JERSEY

08540

(City)

(State)

(Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
Cytosorbents Corp [ CTSO ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director	10% Owner
X	Officer (give title below)	Other (specify below)
	Chief Financial Officer

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
06/15/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

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)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	06/15/2026		P		100,000⁽¹⁾	A	$0.44	638,113⁽²⁾⁽³⁾⁽⁴⁾⁽⁵⁾	D

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 Securities Underlying Derivative Security (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: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
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)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)

Explanation of Responses:

1. The transaction reported on this Form 4 reflects an open market purchase made by the Reporting Person. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $0.40 to $0.45, inclusive. The Reporting Person undertakes to provide to CytoSorbents Corporation (the "Issuer"), any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the ranges set forth in this footnote (1) to this Form 4.

2. Includes (a) 110,000 restricted stock units ("RSUs"), which will be settled into the Issuer's common stock, par value $0.001 per share (the "Common Stock"), upon vesting upon the earlier of (i) a "Change In Control" of the Issuer, as defined in the Reporting Person's employment agreement (the "Employment Agreement"), or (ii) the fourth anniversary from the date of grant, or August 14, 2028, subject to the Reporting Person's continued service as of the applicable vesting date;

3. (continued from footnote 2) (b) 65,000 RSUs, of which 32,500 remain unvested as of the date hereof, and which shall vest as to one-half of the award on each of the first and second anniversaries of the date of grant, subject to the Reporting Person's continued service as of the applicable vesting date and will be settled into Common Stock upon vesting;

4. (continued from footnote 3) (c) 175,000 RSUs, which will be settled into Common Stock upon a "Change In Control" of the Issuer, as defined in the Reporting Person's Employment Agreement, subject to the Reporting Person's continued service as of the applicable vesting date; (d) 71,500 RSUs, which shall vest as to one-half of the award on each of the first and second anniversaries of the date of grant, subject to the Reporting Person's continued service as of the applicable vesting date and will be settled into Common Stock upon vesting; and

5. (continued from footnote 4) (e) 216,613 shares of Common Stock owned by the Reporting Person.

	/s/ Peter J. Mariani	06/16/2026
	** 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 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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Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

Chief Financial Officer Mariani Peter J bought $44,000 worth of shares (100,000 units at $0.44), increasing direct ownership by 19% to 638,113 units (SEC Form 4)