SCHEDULE 13G/A 0000950170-24-014536 0001879507 XXXXXXXX LIVE 3 Class A Common Stock 03/31/2025 0001861795 DEFINITIVE HEALTHCARE CORP. 24477E103 492 OLD CONNECTICUT PATH, SUITE 401 FRAMINGHAM MA 01701 Rule 13d-1(d) Jason Ronald Krantz X1 22159463.00 0.00 22159463.00 0.00 22159463.00 16.9 IN DEFINITIVE HEALTHCARE CORP. 492 OLD CONNECTICUT PATH, SUITE 401, FRAMINGHAM, MA, 01701. Jason Ronald Krantz 492 Old Connecticut Path, Suite 401 Framingham, MA 01701 United States of America Y Row 9 of the Reporting Person's cover page to this Schedule 13G sets forth the aggregate number of shares of securities of the Issuer currently beneficially owned by such Reporting Person and is incorporated by reference. Consists of (i) 450,000 shares of Class A Common Stock, par value $0.001 per share ("Class A Common Stock") held by DH Holdings (fka Jason R. Krantz 2009 Trust), of which the Reporting Person is the trustee and beneficiary, (ii) 368,850 shares of Class A Common Stock held directly by the Reporting Person, (iii) 41,456 shares of Class A Common Stock that are issuable to the Reporting Person upon vesting of restricted stock units and performance-based restricted stock units, within 60 days of March 31, 2025, (iv) 20,451,027 shares of Class A Common Stock of the Issuer that are issuable, at the holder's election, upon exchange of an equal number of Limited Liability Company Units of AIDH Topco, LLC ("LLC Units") held by DH Holdings (fka Jason R. Krantz 2009 Trust), that are currently vested and (v) 848,130 shares of Class A Common Stock that are issuable, at the holder's election, upon exchange of an equal number of vested LLC Units held directly by the Reporting Person. Row 11 of the Reporting Person's cover page to this Schedule 13G sets forth the percentage of the shares of securities of the Issuer currently beneficially owned by such Reporting Person and is incorporated by reference. The Reporting Person beneficially owns 16.9% of the Class A Common Stock of the Issuer, which percentage is based upon the sum of: (i) 109,646,157 shares of Class A Common Stock outstanding as of March 31, 2025 as reported by the Issuer to the Reporting Person, (ii) 21,299,157 shares of Class A Common Stock issuable upon exchange of the Reporting Person's directly and indirectly held vested LLC Units, and (iii) 41,456 shares of Class A Common Stock that are issuable to the Reporting Person upon vesting of restricted stock units and performance-based restricted stock units, within 60 days of March 31, 2025. Row 5 of the Reporting Person's cover page to this Schedule 13G sets forth the number of shares over which the Reporting Person has the sole power to vote or to direct the vote. Row 6 of the Reporting Person's cover page to this Schedule 13G sets forth the number of shares over which the Reporting Person has the shared power to vote or to direct the vote. Row 7 of the Reporting Person's cover page to this Schedule 13G sets forth the number of shares over which the Reporting Person has the sole power to dispose or to direct the disposition of. Row 8 of the Reporting Person's cover page to this Schedule 13G sets forth the number of shares over which the Reporting Person has the shared power to dispose or to direct the disposition of. Y Y Y Y Y Y Jason Ronald Krantz /s/ Jason Ronald Krantz 05/15/2025