Sec Form 4 Filing - SEA VII Management, LLC @ Definitive Healthcare Corp. - 2022-05-10

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person SEA VII Management, LLC 2. Issuer Name and Ticker or Trading Symbol Definitive Healthcare Corp. [ DH] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 140 NEW MONTGOMERY STREET,, 20TH FLOOR 3. Date of Earliest Transaction (MM/DD/YY) 05/10/2022 (Street) SAN FRANCISCO, CA94105 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Class B Common Stock 05/10/2022 J( 1 )( 2 ) 2,717,042 D 24,091,844 I See note( 3 ) Class A Common Stock 05/10/2022 C( 1 )( 2 ) 2,717,042 A 5,508,971 I See note( 3 ) Class A Common Stock 05/10/2022 J( 4 ) 2,993,760( 4 ) D $ 0( 4 ) 2,515,211 I See note( 3 ) Class A Common Stock 05/11/2022 S 1,490( 5 ) D $ 15.55( 5 ) 2,513,721 I See note( 3 ) Class A Common Stock 05/11/2022 S 2,550( 6 ) D $ 15.55( 6 ) 2,511,171 I See note( 3 ) Class A Common Stock 05/11/2022 S 811( 7 ) D $ 16.52( 7 ) 2,510,360 I See note( 3 ) Class A Common Stock 05/11/2022 S 1,389( 8 ) D $ 16.52( 8 ) 2,508,971 I See note( 3 )

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares LLC Units of AIDH Topco, LLC ( 2 ) 05/10/2022 C( 1 )( 2 ) 2,717,042 ( 2 ) ( 2 ) Class A Common Stock 2,717,042( 2 ) ( 1 )( 2 ) 24,091,844 I See note( 3 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other SEA VII Management, LLC 140 NEW MONTGOMERY STREET, 20TH FLOOR SAN FRANCISCO, CA94105 X X SE VII DHC AIV, L.P. 140 NEW MONTGOMERY STREET, 20TH FLOOR SAN FRANCISCO, CA94105 X X SE VII DHC AIV Feeder, L.P. 140 NEW MONTGOMERY STREET, 20TH FLOOR SAN FRANCISCO, CA94105 X X Spectrum VII Investment Managers' Fund, L.P. 140 NEW MONTGOMERY STREET, 20TH FLOOR SAN FRANCISCO, CA94105 X X Spectrum VII Co-Investment Fund, L.P. 140 NEW MONTGOMERY STREET, 20TH FLOOR SAN FRANCISCO, CA94105 X X Spectrum Equity Associates VII, L.P. 140 NEW MONTGOMERY STREET, 20TH FLOOR SAN FRANCISCO, CA94105 X X Signatures SEA VII MANAGEMENT, LLC, By: /s/ Carolina A. Picazo, Chief Administrative Officer & Chief Compliance Officer 05/12/2022 Signature of Reporting Person Date SE VII DHC AIV, L.P., By: Spectrum Equity Associates VII, L.P., its general partner, By: SEA VII Management, LLC, its general partner, By: /s/Carolina A. Picazo, its Chief Administrative Officer & Chief Compliance Officer 05/12/2022 Signature of Reporting Person Date SE VII DHC AIV FEEDER, L.P., By: Spectrum Equity Associates VII, L.P., its general partner, By: SEA Management, LLC, its general partner, By: /s/ Carolina A. Picazo, Chief Administrative Officer & Chief Compliance Officer 05/12/2022 Signature of Reporting Person Date SPECTRUM VII INVESTMENT MANAGERS' FUND, L.P., By: SEA Management, LLC, its general partner, By: /s/ Carolina A. Picazo, Chief Administrative Officer & Chief Compliance Officer 05/12/2022 Signature of Reporting Person Date SPECTRUM VII CO-INVESTMENT FUND, L.P., By: /s/ Carolina A. Picazo, Chief Administrative Officer & Chief Compliance Officer 05/12/2022 Signature of Reporting Person Date SPECTRUM EQUITY ASSOCIATES VII, L.P., By: SEA Management, LLC, its general partner, By: /s/ Carolina A. Picazo, Chief Administrative Officer & Chief Compliance Officer 05/12/2022 Signature of Reporting Person Date

Explanation of Responses:

( 1 )See Exhibit 99.1 for the text of footnote (1). ( 2 )See Exhibit 99.1 for the text of footnote (2). ( 3 )See Exhibit 99.1 for the text of footnote (3). ( 4 )See Exhibit 99.1 for the text of footnote (4). ( 5 )See Exhibit 99.1 for the text of footnote (5). ( 6 )See Exhibit 99.1 for the text of footnote (6). ( 7 )See Exhibit 99.1 for the text of footnote (7). ( 8 )See Exhibit 99.1 for the text of footnote (8).

Remarks: Christopher T. Mitchell, a Managing Director of Spectrum and Jeffrey C. Haywood, a Managing Director of Spectrum (together, the "Spectrum Directors"), each serve on the board of directors of the Issuer, and have been deputized to represent the Repo rting Persons on the board of directors. By virtue of the Spectrum Directors' representation, for purposes of Section 16 of the Securities Exchange Act of 1934, each of the Reporting Persons may be deemed directors by deputization of the Issuer. The Spectrum Directors have filed separate Section 16 reports disclosing securities of the Issuer that they may be deemed to beneficially own for Section 16 purposes.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

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