Indicate by check mark if the registrant is not required to file reports pursuant to Section13 or Section15(d)of the Act.☐Yes☑No Indicate by check mark whether the registrant (1)has filed all reports required to be filed by Section13 or 15(d)of the Securities Exchange Act of 1934during the preceding 12months (or for such shorter period that the registrant was required to file such reports), and (2)has been subject to such filingrequirements for the past 90days.☑Yes☐No Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted and posted pursuant toRule405 of Regulation S-T (§232.405 of this chapter) during the preceding 12months (or for such shorter period that the registrant was required tosubmit such files).YesNo☐ Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company, oremerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and emerging growthcompany in Rule12b-2 of the Exchange Act. Accelerated Filer☐Smaller reporting company☑Emerging growth company☐ Large Accelerated Filer☐Non-accelerated Filer☑ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any newor revised financial accounting standards provided pursuant to Section13(a)of the Exchange Act☐ Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internalcontrol over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C.7262(b)) by the registered public accounting firm thatprepared or issued its audit report.☑ If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in thefiling reflect the correction of an error to previously issued financial statements.☑ Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensationreceived by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b).☐ Indicate by check mark whether the registrant is a shell company (as defined in Rule12b-2 of the Exchange Act.)☐Yes☑No The aggregate market value of the common stock of the registrant held by non-affiliates as of June 30, 2025, the last business day of the registrant’s mostrecently completed second fiscal quarter, was approximately $60.6 million based upon the closing price reported for such date on the Nasdaq CapitalMarket Exchange. As of March 20, 2026, there were approximately 62.7 million outstanding shares of the registrant’s common stock. Documents incorporated by reference: Portions of the registrant’s definitive proxy statement to be filed pursuant to Regulation 14A within 120days after the end of the registrant’sfiscalyear are incorporated by reference into PartIII of this Form10-K and certain documents are incorporated by reference into PartIV of this Form10-K. CYTOSORBENTS CORPORATIONANNUAL REPORT ON FORM10-KTABLE OF CONTENTS iPagePARTIItem1. Business.1Item1A. Risk Factors.18Item1B. Unresolved Staff Comments.33Item 1C. Cybersecurity33Item2. Properties.34Item3. Legal Proceedings.34Item4. Mine Safety Disclosures.34PARTIIItem5. Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of EquitySecurities.35Item6. Reserved35Item7. Management’s Discussion and Analysis of Financial Condition and Results of Operations.35Item7A. Quantitative and Qualitative Disclosures About Market Risk.43Item8. Financial Statements and Supplementary Data.43Item9. Changes in and Disagreements With Accountants on Accounting and Financial Disclosure.43Item9A. Controls and Procedures.44Item9B. Other Information.46Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspection.46PARTIIIItem10. Directors, Executive Officers and Corporate Governance.47Item11. Executive Compensation.47Item12. Security Ownership of Certain Beneficial Owners and Management and Related StockholderMatters.47Item13. Certain Relationships and Related Transactions, and Director Independence.47Item14. Principal Accounting Fees and Services.47PartIVItem15. Exhibits, Financial Statement Schedules.48Item16. Form10-K Summary53 CAUTIONARY NOTEREGARDING FORWARD-LOOKING STATEMENTS This Annual Report on Form10-K, or this Report, contains “forward-looking statements” within the meaningof Section27A of the Securities Act of 1933, as amended, or the Securities Act, and Section21E of the SecuritiesExchange Act of 1934, or the Exchange Act. Forward-looking statements discuss matters that are not historical facts.Because they discuss future events or conditions, forward-looking statements may include words such as