X0609 4 2026-09-04 0 0001175151 Cytosorbents Corp CTSO 0001442786 Chan Phillip P. false C/O CYTOSORBENTS CORPORATION 305 COLLEGE ROAD EAST PRINCETON NJ 08540 1 1 0 0 Chief Executive Officer 0 Common Stock 2026-09-04 4 P 0 200000 0.35 A 1944432 D 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 $0.3470 to $0.3599, 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. Includes: (i) the following restricted stock units ("RSUs") that will be settled into shares of Common Stock upon vesting upon a "Change In Control" of the Company as defined in the Amended and Restated CytoSorbents Corporation 2014 Long-Term Incentive Plan (the "Plan"): (a) 10,300 RSUs granted on March 15, 2018, (b) 18,700 RSUs granted on February 24, 2017, (c) 57,000 RSUs granted on June 7, 2016 and (d) 130,000 RSUs granted on April 8, 2015; (continued from footnote 2) (ii) 52,800 RSUs of 105,600 granted on August 8, 2025, which vest in equal parts at the first and second year anniversaries of the date of grant, subject to the Reporting Person's continued service as of the applicable vesting date, and (iii) 1,475,632 shares of Common Stock owned by the Reporting Person. The shares reported herein were not adjusted to reflect the Issuer's reverse stock split that occurred on September 8, 2026. /s/ Phillip P. Chan 2026-09-09