X0508 4 2026-01-05 0001861795 Definitive Healthcare Corp. DH 0002052043 Heller Casey C/O DEFINITIVE HEALTHCARE CORP. 492 OLD CONNECTICUT PATH, SUITE 401 FRAMINGHAM MA 01701 false true false false Chief Financial Officer false Class A Common Stock 2026-01-05 4 A false 195313 0 A 1275490 D Represents restricted stock units ("RSUs"), each representing a contingent right to receive one share of the Issuer's Class A Common Stock, par value $0.001 (the "Class A Common Stock"), with 50% of the RSUs vesting on January 1, 2027, followed by vesting in equal quarterly installments over the remaining 12 months thereafter, subject to the Reporting Person's continued service with the Issuer through each such vesting date. /s/ Jonathan Paris, Attorney-in-Fact 2026-01-07