X0609 4 2026-09-14 0 0001175151 Cytosorbents Corp CTSO 0001368151 Capponi Vincent false C/O CYTOSORBENTS CORPORATION 305 COLLEGE ROAD EAST PRINCETON NJ 08540 0 1 0 0 President and COO 0 Common Stock 2026-09-14 4 P 0 1800 6.07 A 40114 D Common Stock 2026-09-14 4 P 0 273 5.90 A 40387 D This transaction reported on this Form 4 reflects an open market purchase made by the Reporting Person. Includes: (i) the following RSUs that will be settled into Common Stock upon vesting upon a "Change In Control" of CytoSorbents Corporation (the "Issuer") as defined in the Amended and Restated CytoSorbents Corporation 2014 Long-Term Incentive Plan (the "Plan"): (a) 505 RSUs granted on March 15, 2018, (b) 895 RSUs granted on February 24, 2017, (c) 2,700 RSUs granted on June 7, 2016 and (d) 6,250 RSUs granted on April 8, 2015; (continued from footnote 2) (ii) the following RSUs, which vest in equal parts on the first year anniversary of the date of grant and the second year anniversary of the date of grant, subject to the Reporting Person's continued service as of the applicable vesting date, and will settle into shares of Common Stock of the Company upon vesting: 4,455 RSUs granted on August 8, 2025 and of which 2,228 remain unvested as of the date hereof; and (continued from footnote 3) (iii) 25,736 shares of Common Stock owned by the Reporting Person. Reflects the 1-for-20 reverse stock split effected by the Issuer on September 8, 2026. /s/ Peter J. Mariani attorney-in-fact Vincent Capponi 2026-09-16