X0508 4 2025-11-01 0001861795 Definitive Healthcare Corp. DH 0001879507 Krantz Jason Ronald C/O DEFINITIVE HEALTHCARE CORP. 492 OLD CONNECTICUT PATH, SUITE 401 FRAMINGHAM MA 01701 true false true true EXECUTIVE CHAIRMAN false Class A Common Stock 2025-11-01 4 F false 18796 2.77 D 1060584 D DH Holdings (f/k/a Jason R. Krantz 2009 Trust) 450000 I See footnote Represents the withholding of shares by the Issuer to satisfy the Reporting Person's tax withholding obligations in connection with the vesting and settlement of previously reported restricted stock units. Amount beneficially owned in trust by DH Holdings (f/k/a Jason R. Krantz 2009 Trust), of which the reporting person is the beneficiary. Exhibit 24 - Power of Attorney /s/ Jonathan Paris, Attorney-in-Fact 2025-11-04