April 9, 2024

Dear Stockholder:

You are cordially invited to attend the 2024 Annual Meeting of Stockholders of Definitive Healthcare Corp. on Wednesday, May 22, 2024, at 3:00 PM, Eastern Time. The Annual Meeting will be held at 492 Old Connecticut Path, Suite 401, Framingham, MA 01701.

The Notice of Annual Meeting of Stockholders and Proxy Statement, both of which accompany this letter, provide details regarding the business to be conducted at the Annual Meeting. A Notice of Internet Availability of Proxy Materials is being mailed, and the Proxy Statement, annual report and the form of proxy are first being sent or made available to stockholders on or about April 9, 2024. We urge you to read the accompanying materials regarding the matters to be voted on at the Annual Meeting and to submit your voting instructions by proxy.

Whether or not you plan to attend the Annual Meeting, your vote is important to us. You may vote your shares by proxy on the Internet, by telephone, or by completing, signing and promptly returning a proxy card, or you may vote in person at the Annual Meeting. We encourage you to vote by Internet, by telephone, or by proxy card in advance even if you plan to attend the Annual Meeting. By doing so, you will ensure that your shares are represented and voted at the Annual Meeting.

Thank you for your continued support of Definitive Healthcare Corp.

Sincerely,

Jason Krantz

Executive Chairman, Director, Interim CEO

DEFINITIVE HEALTHCARE CORP.

NOTICE OF ANNUAL MEETING OF STOCKHOLDERS

By Order of the Board of Directors,

Matt Ruderman

Chief Legal Officer and Secretary

April 9, 2024

Important Notice Regarding the Availability of Proxy Materials for the Annual Meeting of Stockholders to Be Held on Wednesday, May 22, 2024: This Proxy Statement and our Annual Report are available free of charge at www.proxydocs.com/DH.

PROXY VOTING METHODS

If at the close of business on March 25, 2024 (the “Record Date”), you were a stockholder of record you may vote your shares in person at the Annual Meeting or in advance over the Internet, by telephone, or by mail. You may also revoke your proxies at the times and in the manners described in the General Information section of this Proxy Statement. We encourage you to vote by Internet, by telephone, or by proxy card in advance even if you plan to attend the Annual Meeting. By doing so, you will ensure that your shares are represented and voted at the Annual Meeting.

Shares Held of Record. If you hold your shares in your own name as a holder of record with our transfer agent, Equiniti Trust Company, LLC, you may authorize that your shares be voted at the Annual Meeting in one of the following ways:

Shares Held in Street Name. If you hold your shares through a broker, bank, or other nominee (that is, in street name), you will receive instructions from your broker, bank, or nominee that you must follow in order to submit your voting instructions and have your shares voted at the Annual Meeting. If you want to vote in person at the Annual Meeting, you may be instructed to obtain a legal proxy from your broker, bank, or other nominee and to submit a copy at the meeting.

YOUR VOTE IS IMPORTANT TO US. THANK YOU FOR VOTING.

Table of Contents

Definitive Healthcare Corp.

492 Old Connecticut Path, Suite 401

Framingham, MA 01701

Telephone: (508) 720-4224

PROXY STATEMENT

Annual Meeting of Stockholders

May 22, 2024

GENERAL INFORMATION

Why am I being provided with these materials?

Pursuant to rules adopted by the Securities and Exchange Commission (the “SEC”), we have elected to provide access to our proxy materials over the internet. Accordingly, the Notice of Internet Availability of Proxy Materials was mailed, and this Proxy Statement, annual report, and the form of proxy were first sent or made available to stockholders on or about April 9, 2024. We have provided these proxy materials to you in connection with the solicitation by the Board of Directors (the “Board” or “Board of Directors”) of Definitive Healthcare Corp. (“we,” “our,” “us” and the “Company”) of proxies to be voted at our Annual Meeting of Stockholders to be held on May 22, 2024 (the “Annual Meeting”), and at any postponements or adjournments of the Annual Meeting. You are invited to attend the Annual Meeting and vote your shares or to vote your shares in advance by proxy via the Internet, by telephone, or by mail.

What am I voting on?

There are three proposals scheduled to be voted on at the Annual Meeting:

Who is entitled to vote?

Stockholders of record as of the close of business on March 25, 2024 (the “Record Date”) may vote at the Annual Meeting or any postponement or adjournment thereof. As of that date, there were 117,789,185 shares of our Class A common stock and 39,238,832 shares of our Class B common stock outstanding. Holders of our Class A common stock have one vote for each share of Class A common stock held as of the Record Date, and holders of our Class B common stock have one vote for each share of Class B common stock held as of the Record Date, in each case including shares:

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Our Class A common stock and Class B common stock will vote together as a single class on all matters described in this Proxy Statement for which stockholder votes are being solicited.

What constitutes a quorum?

The presence in person or by proxy of the holders of record of a majority in voting power of the shares entitled to vote at the Annual Meeting shall constitute a quorum. Abstentions, “withhold” votes, and shares represented by “broker non-votes” that are present in person or by proxy and entitled to vote at the Annual Meeting are counted for purposes of determining a quorum.

What is a “broker non-vote”?

A broker non-vote occurs when shares held through a broker are not voted with respect to a proposal because (1) the broker has not received voting instructions from the stockholder who beneficially owns the shares and (2) the broker lacks the authority to vote the shares at its discretion. Proposal Nos. 1 and 3 are considered non-routine matters, and a broker will lack the authority to vote uninstructed shares at their discretion on such proposal. Proposal No. 2 is considered a routine matter, and a broker will be permitted to exercise its discretion to vote uninstructed shares on this proposal.

How many votes are required to approve each proposal?

For Proposal No. 1, under our Amended and Restated Certificate of Incorporation (“Charter”), directors are elected by the plurality of the votes cast by the holders of shares present in person or represented by proxy at the meeting and entitled to vote thereon. There is no cumulative voting. Director nominees who receive the greatest number of affirmative votes will be elected. In an uncontested election where the number of nominees equals the number of director seats up for election, all the nominees will be elected as long as there is a quorum and they receive at least one vote. Under our Corporate Governance Guidelines, we maintain a policy that requires a director in an uncontested election who does not receive a majority of the votes cast to tender his or her resignation from the Board and all committees thereof. Under our Corporate Governance Guidelines, a director nominee shall have failed to receive the affirmative vote of a majority of votes cast if the number of “withhold” votes in respect of such director nominee’s election exceeds the number of votes “for” such director nominee’s election (excluding broker non-votes). The Nominating and Corporate Governance Committee will assess the appropriateness of the nominee continuing to serve as a director and will recommend to the Board the action to be taken with respect to the resignation. The Board will act on the Nominating and Corporate Governance Committee’s recommendation and publicly disclose its decision and rationale within 90 days from the publication of the election results.

For Proposal No. 2, under our Bylaws, approval of the proposal requires the affirmative vote of the holders of a majority in voting power of the shares of stock present in person or by proxy and entitled to vote thereon. It is important to note that Proposal No. 2 is advisory and therefore not binding on the Board. While the ratification of Deloitte & Touche LLP as our independent registered public accounting firm is not required by our Bylaws or otherwise, if our stockholders fail to ratify the selection, we will consider it notice to the Board and the Audit Committee to consider, in their discretion, the selection of a different firm. In addition, even if the selection is ratified, the Board and the Audit Committee may, in their discretion, direct the appointment of a different firm if at any time during the year they determine that such a change would be in the best interests of the Company and its stockholders.

For Proposal No. 3, under our Bylaws, approval of the proposal requires the affirmative vote of the holders of a majority in voting power of the shares of stock present in person or by proxy and entitled to vote thereon. It is important to note that Proposal No. 3 is advisory and therefore not binding on the Board. Nevertheless, the Board and the Human Capital Management and Compensation Committee value the opinions of stockholders in this matter and, to the extent there is any significant vote in opposition to the compensation of the Company’s named executive officers, even if less than a majority, the Board will consider the stockholders’ concerns and evaluate any appropriate next steps.

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How are votes counted?

With respect to the election of directors (Proposal No. 1), you may vote “FOR” or “WITHHOLD” with respect to each nominee. Votes that are “withheld” will not count as a vote “FOR” or “AGAINST” a director because directors are elected by plurality voting; however, votes that are “withheld” may trigger the director resignation policy set forth in our Corporate Governance Guidelines as described elsewhere in this Proxy Statement. Broker non-votes will have no effect on the outcome of Proposal No. 1 and there will not be any abstentions on this proposal.

With respect to the ratification of our independent registered public accounting firm (Proposal No. 2), you may vote “FOR,” “AGAINST,” or “ABSTAIN.” Abstentions will have the same effect as a vote “AGAINST” Proposal No. 2 and broker non-votes would have no effect on the outcome of Proposal No. 2. Because brokers have the discretionary authority to vote on Proposal No. 2, we do not expect any broker non-votes on this proposal.

With respect to advisory approval of the compensation of our named executive officers (Proposal No. 3), you may vote “FOR,” “AGAINST,” or “ABSTAIN.” Abstentions will have the same effect as a vote “AGAINST” Proposal No. 3. Broker non-votes will have no effect on the outcome of Proposal No. 3.

If you sign and submit your proxy card without voting instructions, your shares will be voted in accordance with the recommendation of the Board with respect to the Proposals.

We are not aware of any matters to be voted on by stockholders at the Annual Meeting other than those referenced above. If any matter is properly presented at the Annual Meeting, your executed proxy gives your proxy holder discretionary authority to vote your shares in accordance with their best judgment with respect to the matter.

How does the Board recommend that I vote?

Our Board recommends that you vote your shares:

Who will count the vote?

Representatives of Mediant Communications or its designee will tabulate the votes and act as inspectors of election.

How do I vote my shares without attending the Annual Meeting?

If you are a stockholder of record, you may vote by authorizing a proxy to vote on your behalf at the Annual Meeting. Specifically, you may authorize a proxy:

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If you hold your shares in street name, you may submit voting instructions to your broker, bank, or other nominee. In most instances, you will be able to do this over the Internet, by telephone, or by mail. Please refer to information from your bank, broker, or other nominee on how to submit voting instructions.

How do I attend and vote my shares at the Annual Meeting?

This year’s Annual Meeting will be held at 492 Old Connecticut Path, Suite 401, Framingham, MA 01701. The instructions for how to attend the Annual Meeting and vote, including how to demonstrate proof of stock ownership, are posted at www.proxydocs.com/DH.

What does it mean if I receive more than one proxy card on or about the same time?

It generally means you hold shares registered in more than one account. To ensure that all your shares are voted, please sign and return each proxy card or, if you vote by Internet or telephone, vote once for each proxy card you receive.

May I change my vote or revoke my proxy?

Yes. Whether you have voted by Internet, telephone, or mail, if you are a stockholder of record, you may change your vote and revoke your proxy by:

If you hold shares in street name, please refer to information from your bank, broker, or other nominee on how to revoke or submit new voting instructions.

Could other matters be decided at the Annual Meeting?

We are not aware of any matters to be voted on by stockholders at the Annual Meeting other than those referenced above. If any matter is properly presented at the Annual Meeting, your executed proxy gives your proxy holder discretionary authority to vote your shares in accordance with their best judgment with respect to the matter.

Who will pay for the cost of this proxy solicitation?

We will pay the cost of soliciting proxies. Proxies may be solicited on our behalf by directors, officers, or employees of the Company (for no additional compensation) in person or by telephone, electronic transmission, and facsimile transmission. Brokers and other nominees will be requested to solicit proxies or authorizations from beneficial owners and will be reimbursed for their reasonable expenses.

The information provided in the “question and answer” format above is for your convenience only and is merely a summary of the information contained in this Proxy Statement. You should read this entire Proxy Statement carefully. Information contained on, or that can be accessed through, our website is not intended to be incorporated by reference into this Proxy Statement and references to our website address in this Proxy Statement are inactive textual references only.

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PROPOSAL NO. 1—ELECTION OF CLASS III DIRECTORS

Our Charter provides for a classified Board of Directors divided into three classes. Jeff Haywood, Scott Stephenson, and Kathleen A. Winters constitute a class with a term that expires at the Annual Meeting of Stockholders in 2027 (the “Class III Directors”); Jason Krantz and Lauren Young constitute a class with a term that expires at the Annual Meeting of Stockholders in 2025 (the “Class I Directors”); and Chris Egan, Samuel A. Hamood, Jill Larsen, and Sastry Chilukuri constitute a class with a term that expires at the Annual Meeting of Stockholders in 2026 (the “Class II Directors”). Upon the recommendation of the Nominating and Corporate Governance Committee, the Board of Directors has considered and nominated the following slate of nominees to serve as Class III Directors for a three-year term expiring at the Annual Meeting of Stockholders in 2027: Jeff Haywood, Scott Stephenson, and Kathleen A. Winters. Action will be taken at the Annual Meeting for the election of these three Class III Director nominees.

Unless otherwise instructed, the persons named in the form of proxy card (the “proxyholders”) included with this Proxy Statement intend to vote the proxies held by them “FOR” the election of the director nominees. All of the nominees have indicated that they will be willing and able to serve as directors. Each person nominated for election has agreed to be named in this Proxy Statement and to serve if elected. We have no reason to believe that any of the nominees will be unavailable or, if elected, will decline to serve. In the event that any of the nominees should be unable to serve or for good cause will not serve, proxies will be voted for a substitute as designated by the Board, or alternatively, the Board may leave a vacancy on the Board or reduce the size of the Board.

Nominating Agreements

On September 17, 2021, in connection with the initial public offering of our Class A common stock completed September 17, 2021(our “IPO”), we entered into nominating agreements with each of an affiliate of Advent, Jason Krantz, and Spectrum Equity, which provide that, subject to certain stock ownership thresholds, the Company will include two designees of Advent, one designee of Jason Krantz, and one designee of Spectrum Equity, respectively, in the slate of director nominees recommended to the Company’s stockholders for election, and the Company will fill any vacancy of any such designated director previously nominated by Advent, Jason Krantz, and Spectrum Equity, respectively, with a new director designated by Advent, Jason Krantz, and Spectrum Equity, respectively. Chris Egan and Lauren Young are the designees of Advent, Jason Krantz is the designee of Jason Krantz, and Jeff Haywood is the designee of Spectrum Equity.

Nominees for Election to the Board of Directors in 2024

The following information describes the offices held, other business directorships, and the term of service of each director nominee, as well as the experiences, qualifications, attributes, or skills that caused the Nominating and Corporate Governance Committee and the Board to determine that the director nominee should serve as a director. Beneficial ownership of equity securities of the director nominees is shown under “Security Ownership of Certain Beneficial Owners and Management” below. Each of the nominees for election at the Annual Meeting was recommended for election by the Nominating and Corporate Governance Committee. All three of the nominees are current directors and, if elected, will be continuing their roles on the Board. Mr. Stephenson has not previously been elected by our stockholders. His candidacy was recommended by one of our non-management directors. After performing further evaluation of Mr. Stephenson’s particular experience, qualifications, attributes, and skills, the Nominating and Corporate Governance Committee recommended his appointment to the Board.

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Class III – Nominees for term expiring in 2027

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THE BOARD OF DIRECTORS RECOMMENDS THAT YOU VOTE “FOR” THE ELECTION OF

EACH OF THE DIRECTOR NOMINEES NAMED ABOVE.

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Continuing Members of the Board of Directors

The following information describes the offices held, other business directorships, and the class and term of each director whose term continues beyond the Annual Meeting and who is not subject to election this year, as well as the experiences, qualifications, attributes, or skills that caused the Board to determine that the director should serve as a director. Beneficial ownership of equity securities for these directors is also shown under “Security Ownership of Certain Beneficial Owners and Management” below.

Class I – Directors whose term expires in 2025

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Class II – Directors whose term expires in 2026

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THE BOARD OF DIRECTORS AND CERTAIN GOVERNANCE MATTERS

Our business and affairs are managed under the direction of our Board. Our Charter provides that our Board must consist of at least one director, or such larger number as may be fixed from time to time by a resolution of at least a majority of the directors then in office. Our Board is composed of ten directors divided into three classes, with terms staggered according to class. See “Proposal No. 1 – Election of Class III Directors” for more information.

Director Independence and Independence Determinations

Under our Corporate Governance Guidelines, the Board is required to have a majority of independent directors. In making independence determinations, the Board observes all applicable requirements, including the corporate governance listing standards established by the Nasdaq Stock Market (“Nasdaq”). The Board carefully considers all relevant facts and circumstances in making an independence determination.

Our Board of Directors affirmatively determined that each of Sastry Chilukuri, Chris Egan, Samuel A. Hamood, Jeff Haywood, Jill Larsen, Chris Mitchell, Scott Stephenson, Kathleen Winters, and Lauren Young is independent under applicable Nasdaq listing standards. Our Board also determined that each of Sastry Chilukuri, Samuel A. Hamood, and Kathleen Winters is independent under Section 10A-3 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) for purposes of serving on the Audit Committee, and that each of Jeff Haywood, Jill Larsen, and Lauren Young is independent for purposes of serving on the HCM and Compensation Committee. Mr. Mitchell resigned from the Board effective September 6, 2023. In making its independence determinations, our Board of Directors considered and reviewed all information known to it, including information identified through annual director questionnaires. In the case of Mr. Egan and Ms. Young, our Board of Directors considered their positions as a Managing Partner and Managing Director, respectively, of Advent. In the case of Mr. Haywood and Mr. Mitchell, our Board of Directors considered their positions as Managing Directors at Spectrum Equity. In the case of Mr. Stephenson, our Board of Directors considered his position as an Advisory Partner at Advent.

Director Nomination Process

Currently, the Board of Directors is divided into three classes. Each year, at the Annual Meeting of Stockholders, the Board proposes a slate of director nominees for a particular class to stockholders for election to a term of three years. Stockholders may also recommend candidates for election to the Board, as described below. The Board has delegated the process of screening potential director candidates to the Nominating and Corporate Governance Committee.

The Nominating and Corporate Governance Committee is responsible for periodically reviewing with the Board the appropriate criteria that directors are required to fulfill (including experience, qualifications, attributes, skills, and other characteristics) in the context of the current make-up of the Board and the needs of the Board given the circumstances of the Company. In identifying and screening director candidates, the Nominating and Corporate Governance Committee considers whether the candidates fulfill the criteria for directors approved by the Board, including integrity, objectivity, independence, sound judgment, leadership, courage, and diversity of experience (for example, in relation to finance and accounting, strategy, risk management, technical expertise, policymaking, etc.). In addition, the Company recognizes and embraces the benefits of having a diverse Board. In evaluating the Board’s composition, although the Board does not have a formal policy specifying how diversity of background and personal experience should be applied in identifying or evaluating director candidates, the Nominating and Corporate Governance Committee considers diversity among other relevant considerations, including, but not limited to, diversity of gender, age, race, ethnicity, cultural and educational background, professional experience, skills, knowledge, and length of service.

The Nominating and Corporate Governance Committee values the input of stockholders in identifying director candidates. The Nominating and Corporate Governance Committee considers recommendations for Board candidates submitted by stockholders using the same criteria it applies to recommendations from the committee,

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directors, and members of management. Stockholders may submit recommendations by providing the person’s name and appropriate background and biographical information in writing to the Nominating and Corporate Governance Committee at Definitive Healthcare Corp., Attn: Chief Legal Officer, 492 Old Connecticut Path, Suite 401, Framingham, MA 01701. Invitations to serve as a nominee are extended by the Board via the Chair of the Board and the Chair of the Nominating and Corporate Governance Committee.

Director Resignation Policy

Directors are elected by a plurality of the votes cast in both contested elections (elections in which the number of nominees is greater than the number of Board seats open for election) and uncontested elections (elections in which the number of nominees does not exceed the number of Board seats open for election). Under our Corporate Governance Guidelines, we maintain a policy that requires a director in an uncontested election who does not receive a majority of the votes cast to tender his or her resignation from the Board and all committees thereof. Under our Corporate Governance Guidelines, a director nominee shall have failed to receive the affirmative vote of a majority of votes cast if the number of “withhold” votes in respect of such director nominee’s election exceeds the number of votes “for” such director nominee’s election (excluding broker non-votes). The Nominating and Corporate Governance Committee will assess the appropriateness of the nominee continuing to serve as a director and will recommend to the Board the action to be taken with respect to the resignation. The Board will act on the Nominating and Corporate Governance Committee’s recommendation and publicly disclose its decision and rationale within 90 days from the publication of the election results.

Board Leadership Structure

Our Board of Directors is led by Mr. Krantz, our Executive Chairman and Founder, who also currently serves as our interim Chief Executive Officer. At this time, we believe that a combined Chair and interim Chief Executive Officer role is appropriate for the Company and in the best interests of the Company and its stockholders. As the interim Chief Executive Officer and Founder, Mr. Krantz has a deep understanding of the Company, which we believe enables the Board to better understand the Company, work closely with management, and ensure that the Board and management act with a common purpose. We believe Mr. Krantz offers a robust understanding of risks facing the Company as our Founder and interim Chief Executive Officer. We believe that combining the positions of interim Chief Executive Officer and Executive Chairman provides a single, clear chain of command to execute our strategic initiatives and business plans, and that a single Executive Chairman and interim Chief Executive Officer is well-positioned to act as a bridge between management and the Board, facilitating the regular flow of information. The Board does not have a fixed policy regarding the separation of the offices of Chair of the Board and Chief Executive Officer and believes that it should maintain the flexibility to select the Chair of the Board and its leadership structure, from time to time, based on the criteria that it deems in the best interests of the Company and its stockholders. The Board believes that this flexibility is in the best interest of the Company and that a one-size-fits-all approach to corporate governance, with a mandated independent Chairman, would not result in better governance or oversight.

Oversight of Risk Management

The Board is involved in the oversight of risk management related to us and our business. The Board accomplishes this oversight both directly and through its committees, which assist the Board in overseeing parts of our overall risk management and regularly report to the Board. The Audit Committee periodically reviews our accounting, reporting, and financial practices, and oversees the integrity of our financial statements, the administrative and financial controls, our compliance with legal and regulatory requirements, our procedures for the treatment of complaints regarding internal accounting controls or auditing matters, and our policies with respect to risk assessment and risk management. In addition, our Audit Committee addresses the Company’s cybersecurity risk management as part of its general oversight function. The audit committee is responsible for overseeing Company’s cybersecurity risk management processes, including oversight of risks from cybersecurity threats. Through its regular meetings with management, including the finance, legal, cybersecurity, and internal

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control functions, the Audit Committee reviews and discusses significant areas of our business and related risks and summarizes for the Board areas of risk and any mitigating factors. In addition, the HCM & Compensation Committee reviews, at least annually, whether risks arising from the Company’s compensation policies and practices for all employees, including executive officers, are reasonably likely to have a material adverse effect on the Company. For more information regarding our risk oversight governance framework, see below under “Our Commitment to ESG.”

Executive Sessions

As described in our Corporate Governance Guidelines, the non-management directors meet regularly in executive session without members of management present. If any of the non-management directors do not qualify as an “independent director” under applicable Nasdaq rules, at least once a year an additional executive session is held, attended only by independent directors. The executive sessions have such agendas and procedures as are determined by the non-management and independent directors, as applicable. An independent presiding director convenes and presides at such sessions. Authority in such sessions to act on behalf of the Company or the Board on any matters requires an express delegation of authority by the Board.

Communications with the Board

As described in our Corporate Governance Guidelines, stockholders are invited to communicate to the Board or its committees by writing to Definitive Healthcare Corp., Attn: Chief Legal Officer, 492 Old Connecticut Path, Suite 401, Framingham, MA 01701. In addition, interested parties may communicate with the Chair of the Board or with the non-management and independent directors of the Company as a group by writing to Definitive Healthcare Corp., Attn: Chief Legal Officer, 492 Old Connecticut Path, Suite 401, Framingham, MA 01701.

Board Committees and Meetings

The following table summarizes the current membership of each of the Board’s committees and the number of meetings held by each committee during the year ended December 31, 2023.

During the year ended December 31, 2023, the Board held 13 meetings. In 2023, all of our directors attended at least 75% of the meetings of the Board and committees during the time in which he or she served as a member of

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the Board or such committee. Directors are invited, but not required, to attend our annual meetings of stockholders. 2 out of 10 then-serving directors attended the 2023 annual meeting of stockholders.

Audit Committee

The primary purposes of our Audit Committee under the committee’s charter are to assist the Board’s oversight of:

Our Audit Committee is composed of Samuel A. Hamood, Kathleen A. Winters, and Sastry Chilukuri, with Mr. Hamood serving as chair. Our Board determined that each of Mr. Hamood, Ms. Winters, and Mr. Chilukuri meets the Nasdaq financial literacy requirements for serving on an audit committee and that each of Mr. Hamood and Ms. Winters qualify as an “audit committee financial expert” as such term has been defined by the SEC in Item 407(d) of Regulation S-K. Our Board affirmatively determined that each of Mr. Hamood, Ms. Winters, and Mr. Chilukuri is independent for the purposes of serving on the Audit Committee under applicable Nasdaq rules and Rule 10A-3 under the Exchange Act. The Audit Committee is governed by a charter that complies with the rules of Nasdaq.

Human Capital Management & Compensation Committee

The primary purpose of our Human Capital Management and Compensation Committee (“HCM and Compensation Committee”) under the committee’s charter is to assist the Board in overseeing our employee compensation philosophy and practices, non-Chief Executive Officer succession planning, and human capital management, including:

The HCM and Compensation Committee is composed of Jeff Haywood, Jill Larsen, and Lauren Young, with Ms. Larsen serving as the chair. Our Board affirmatively determined that each of Mr. Haywood, Ms. Larsen, and

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Ms. Young is independent for purposes of serving on the HCM and Compensation Committee. The HCM and Compensation Committee is governed by a charter that complies with the rules of Nasdaq.

Nominating and Corporate Governance Committee

The primary purpose of our Nominating and Corporate Governance Committee is to recommend candidates for appointment to the Board and to review the corporate governance guidelines of the Company, including:

The Nominating and Corporate Governance Committee is composed of Scott Stephenson, Lauren Young, and Sastry Chilukuri, with Ms. Young serving as the chair. Our Board affirmatively determined that each of Mr. Stephenson, Ms. Young and Mr. Chilukuri is independent for purposes of serving on our Board under applicable Nasdaq rules. The Nominating and Corporate Governance Committee is governed by a charter that complies with the rules of Nasdaq. Mr. Mitchell served on the Nominating and Corporate Governance Committee during his term as a director in 2023 and was determined to be independent during his time as a director under applicable Nasdaq rules.

Code of Business Conduct and Ethics

Our Code of Business Conduct and Ethics, which applies to all of our employees, officers (including the principal executive officer, principal financial officer, principal accounting officer, controller and persons performing similar functions), and directors, is available on our website located at ir.definitivehc.com. We intend to post on this section of our website any amendment to our Code of Business Conduct and Ethics, as well as any waivers of our Code of Business Conduct and Ethics, that are required to be disclosed by the rules of the SEC or Nasdaq. Our Audit Committee is responsible for overseeing the Code of Business Conduct and Ethics, and our Board must approve any waivers of the Code of Business Conduct and Ethics for any directors, executive officers, or senior financial officers.

Committee Charters and Corporate Governance Guidelines

Our commitment to good corporate governance is reflected in our Corporate Governance Guidelines, which describe our Board’s views and policies on a wide range of governance topics. These Corporate Governance Guidelines are reviewed from time to time by our Nominating and Corporate Governance Committee and, to the extent deemed appropriate in light of emerging practices, revised accordingly, upon recommendation to and approval by our Board of Directors.

Our Corporate Governance Guidelines, committee charters, Code of Business Conduct and Ethics, and other corporate governance documents and information are available on our website at ir.definitivehc.com under Governance. Any stockholder may also request them in print, without charge, by contacting the Chief Legal Officer of Definitive Healthcare Corp., at 492 Old Connecticut Path, Suite 401, Framingham, MA 01701.

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Our Commitment to ESG

Our Board, acting directly and through its committees, reviews and oversees our strategic plans, objectives, and risks related to sustainability, environmental, social, and governance matters (“ESG”), pursuant to our Corporate Governance Guidelines. At this time, the Board believes full board oversight, with specific elements delegated to committees, rather than assigning oversight to an existing or new committee, will ensure all directors are actively engaged in overseeing ESG risks and opportunities. Each of our committees share in ESG oversight responsibilities, and each committee reports regularly to the full Board on its activities. The HCM and Compensation Committee is responsible for overseeing the policies and strategies relating to talent management, as well as the diversity, equity, and inclusion philosophy, efforts, and results. The Nominating and Corporate Governance Committee oversees our broader ESG framework and general approach to ESG reporting, and reviews and makes recommendations to the Board about significant emerging corporate governance issues and practices. The Audit Committee reviews controls and risks around information security and data privacy and approves procedures and security measures undertaken to strengthen and support compliance in this area. The Audit Committee also provides specific oversight with respect to the financial reporting elements of ESG disclosures.

Board Diversity

The following table sets forth certain self-identified diversity statistics concerning the members of the Board of Directors:

Our Board Diversity Matrix as of April 20, 2023 can be found in our proxy statement for the 2023 Annual Meeting filed with the SEC on April 20, 2023.

Executive Officers of the Company

Set forth below is certain information regarding each of our current executive officers, other than Mr. Krantz, who also serves as a director of the Company. For biographical information for Mr. Krantz, see “Proposal No. 1—Election of Class I Directors—Continuing Members of the Board of Directors.”

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PROPOSAL NO. 2—RATIFICATION OF INDEPENDENT REGISTERED

PUBLIC ACCOUNTING FIRM

The Audit Committee has appointed Deloitte & Touche LLP to serve as our independent registered public accounting firm for the fiscal year ending December 31, 2024.

Although ratification is not required by our Bylaws or otherwise, the Board is submitting the selection of Deloitte & Touche LLP to our stockholders for ratification because we value our stockholders’ views on the Company’s independent registered public accounting firm. If our stockholders fail to ratify the selection, it will be considered as notice to the Board and the Audit Committee to consider the selection of a different firm. Even if the selection is ratified, the Audit Committee, in its discretion, may select a different independent registered public accounting firm at any time if it determines that such a change would be in the best interests of the Company and our stockholders.

A representative of Deloitte & Touche LLP is expected to attend the Annual Meeting. The representative will also have the opportunity to make a statement if he or she desires to do so, and the representative is expected to be available to respond to appropriate questions.

The shares represented by your proxy will be voted “FOR” the ratification of the selection of Deloitte & Touche LLP unless you specify otherwise.

Audit and Non-Audit Fees

In connection with the audit of the 2023 financial statements, we entered into an agreement with Deloitte & Touche LLP which sets forth the terms by which Deloitte & Touche LLP will perform audit services for the Company.

The following table summarizes fees for professional services rendered by our independent registered public accounting firm, Deloitte & Touche LLP, the member firms of Deloitte Touche Tohmatsu, and their respective affiliates, in the identified categories for the years ended December 31, 2023 and 2022:

All of the services shown in this table for 2023 and 2022 were pre-approved by the Audit Committee. The Audit Committee considered whether providing the non-audit services shown in this table was compatible with maintaining Deloitte & Touche LLP’s independence and concluded that it was.

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Pre-Approval Policy for Services of Independent Registered Public Accounting Firm

Consistent with SEC policies regarding auditor independence and the Audit Committee’s charter, the Audit Committee has responsibility for engaging, setting compensation for, and reviewing the performance of the independent registered public accounting firm. In exercising this responsibility, the Audit Committee pre-approves all audit and permitted non-audit services provided by any independent registered public accounting firm prior to each engagement.

THE BOARD OF DIRECTORS RECOMMENDS THAT YOU VOTE “FOR” THE RATIFICATION OF DELOITTE & TOUCHE LLP AS OUR INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM FOR THE FISCAL YEAR ENDING DECEMBER 31, 2024.

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REPORT OF THE AUDIT COMMITTEE

The information contained in this report is not to be deemed to be “soliciting material” or to be “filed” with the SEC, or subject to Regulation 14A of the Exchange Act or to the liabilities of Section 18 of the Exchange Act, nor is such information to be incorporated by reference into any future filing under the Securities Exchange Act of 1933, as amended, or the Exchange Act, except to the extent that we specifically incorporate it by reference into such filing.

The Audit Committee operates pursuant to a charter which is reviewed annually by the Audit Committee. Additionally, a brief description of the primary responsibilities of the Audit Committee is included in this Proxy Statement under “The Board of Directors and Certain Governance Matters—Board Committees and Meetings—Audit Committee.” Under the Audit Committee charter, our management is responsible for the preparation, presentation, and integrity of our financial statements, the application of accounting and financial reporting principles, and our internal controls and procedures designed to assure compliance with accounting standards and applicable laws and regulations. The independent registered public accounting firm is responsible for auditing our financial statements and expressing an opinion as to their conformity with accounting principles generally accepted in the United States of America.

In the performance of its oversight function, the Audit Committee reviewed and discussed the audited financial statements of the Company with management and with the independent registered public accounting firm. The Audit Committee also discussed with the independent registered public accounting firm the matters required to be discussed by the applicable requirements of the Public Company Accounting Oversight Board (“PCAOB”) and the SEC. In addition, the Audit Committee received the written disclosures and the letter from the independent registered public accounting firm required by applicable requirements of the PCAOB regarding the independent registered public accounting firm’s communications with the Audit Committee concerning independence and discussed with the independent registered public accounting firm their independence.

Based upon the review and discussions described in the preceding paragraph, the Audit Committee recommended to the Board that the audited financial statements of the Company be included in the Annual Report on Form 10-K for the fiscal year ended December 31, 2023 for filing with the SEC.

Submitted by the Audit Committee of the Company’s Board of Directors:

Samuel A. Hamood, Chair

Kathleen A. Winters

Sastry Chilukuri

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PROPOSAL NO. 3—ADVISORY VOTE ON EXECUTIVE COMPENSATION

Under the Dodd-Frank Wall Street Reform and Consumer Protection Act, or the Dodd-Frank Act, and Section 14A of the Exchange Act, the Company’s shareholders are entitled to vote to approve, on an advisory basis, the compensation of the Company’s named executive officers as disclosed in this proxy statement in accordance with SEC rules.

This vote is not intended to address any specific item of compensation, but rather the overall compensation of the Company’s named executive officers and the philosophy, policies and practices described in this proxy statement. The compensation of the Company’s named executive officers subject to the vote is disclosed in the Compensation Discussion and Analysis, the compensation tables, and the related narrative disclosure contained in this proxy statement. As discussed in those disclosures, the Company believes that its compensation policies and decisions are focused on pay-for-performance principles, strongly aligned with our shareholders’ interests, and consistent with current market practices. Compensation of the Company’s named executive officers is designed to enable the Company to attract and retain talented and experienced executives to lead the Company successfully in a competitive environment.

Accordingly, the Board is asking the shareholders to indicate their support for the compensation of the Company’s named executive officers as described in this proxy statement by casting a non-binding advisory vote “FOR” the following resolution:

“RESOLVED, that the compensation paid to the Company’s named executive officers as disclosed pursuant to Item 402 of Regulation S-K, including the Compensation Discussion and Analysis, compensation tables, and narrative discussion, is hereby approved.”

Because the vote is advisory, it is not binding on the Board of Directors or the Company. Nevertheless, the views expressed by the shareholders, whether through this vote or otherwise, are important to management and the Board and, accordingly, the Board and the HCM & Compensation Committee intend to consider the results of this vote in making determinations in the future regarding executive compensation arrangements.

Advisory approval of this proposal requires the vote of the holders of a majority in voting power of the shares of stock present in person or by proxy and entitled to vote thereon at the annual meeting. Unless the Board decides to modify its policy regarding the frequency of soliciting advisory votes on the compensation of the Company’s named executives, the next scheduled say-on-pay vote will be at the 2025 Annual Meeting of Stockholders.

THE BOARD OF DIRECTORS RECOMMENDS THAT YOU VOTE “FOR” THE COMPENSATION OF OUR NAMED EXECUTIVE OFFICERS.

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COMPENSATION DISCUSSION & ANALYSIS

This Compensation Discussion & Analysis (“CD&A”) explains our executive compensation program for our named executive officers (“named executive officers” or “NEOs”) listed below. This CD&A also describes the HCM & Compensation Committee’s process for making pay decisions, as well as its rationale for specific decisions related to the fiscal year ended December 31, 2023.

Our NEOs for fiscal 2023 were:

2024 CEO Transition

As disclosed in our current report on Form 8-K filed with the SEC on January 16, 2024, t Mr. Musslewhite stepped down as the Company’s Chief Executive Officer and as a member of the Company’s Board of Directors, each effective January 16, 2024. On such date, the Company also announced that Jason Krantz, the Company’s Founder and Executive Chairman, would serve as interim Chief Executive Officer, effective January 16, 2024. The Board has engaged a leading global executive search firm and a process to identify a permanent CEO is underway.

EXECUTIVE SUMMARY

At Definitive Healthcare, our mission is to transform data, analytics, and expertise into healthcare commercial intelligence. We help clients uncover the right markets, opportunities, and people, so our customers can shape tomorrow’s healthcare industry. Our SaaS platform creates new paths to commercial success in the healthcare market, so companies can identify where to go next.

Since our IPO in September 2021, we have experienced strong cumulative revenue growth and continue to produce strong results. Our strength is broad-based across all of our customer verticals, and we continue to innovate to build the next generation of healthcare commercial intelligence solutions.

2023 Business Highlights

The Company delivered solid performance in 2023. We took action to improve the margin profile of the business and added meaningful capabilities through organic innovation and strategic acquisitions. For the year, we delivered a 13% year-over-year revenue growth rate, a (115)% net loss margin, and a 30% adjusted EBITDA margin. We believe we are well positioned for the long term with a leadership position in a large and attractive market, supporting predictable revenue growth, adjusted EBITDA profitability, and capital efficiency. We have

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demonstrated our ability to effectively grow and scale the business, while adapting to a tougher macroeconomic backdrop. We maintain a clear focus on maximizing our long-term success and value creation for customers and shareholders.

The following are key Company financial and strategic highlights for 2023:

Adjusted EBITDA and Adjusted EBITDA Margin are non-GAAP financial measures. See Appendix A below for more information about these non-GAAP financial measures and for reconciliations of these non-GAAP measures to the most directly comparable GAAP financial measures.

2023 Compensation Highlights

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Our executive compensation program has three primary elements: base salary, annual incentives, and long-term equity incentives. Each of these compensation elements serves a specific purpose in our compensation strategy. Base salary is an essential component of any market-competitive compensation program. Annual incentives reward the achievement of short-term goals, while long-term incentives drive our NEOs to focus on long-term, sustainable stockholder value creation. Based on our performance and consistent with the design of our program, we made the following executive compensation decisions for fiscal 2023:

In addition, based on individual results, the HCM & Compensation Committee approved 100% attainment of the individual performance component of the 2023 Bonus Program for the NEOs. For more information, please refer to the “Annual Incentives” section of this CD&A below.

For additional detail regarding Ms. Lazorchak’s new-hire compensation package, please see the headings “—2023 Executive Compensation Program—Long-Term Equity Incentives” in this CD&A and the heading “—Employment Agreements” in the narratives to the Summary Compensation Table.

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Compensation Practices & Policies

We believe the following practices and policies within our program promote sound compensation governance and are in the best interests of our stockholders and executives:

Stockholder Say-on-Pay Vote

Our stockholders will have their first opportunity to cast a non-binding advisory vote to approve our executive compensation program for our NEOs at our 2024 annual meeting of stockholders. In the future, we intend to consider the outcome of such say-on-pay votes when making compensation decisions regarding our executive compensation program. Unless the Board decides to modify its policy regarding the frequency of soliciting advisory votes on the compensation of the Company’s named executives, we expect to hold say-on-pay votes annually.

WHAT GUIDES OUR PROGRAM

Executive Compensation Philosophy and Objectives

Our executive compensation philosophy is driven by the following guiding principles that underpin the critical connections between performance, long-term value creation, talent management, compensation governance, and our cultural values:

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Elements of Pay: Total Direct Compensation

Our executive compensation philosophy is supported by the following principal elements of pay:

In evaluating our executive compensation policies and programs, as well as the short-term and long-term value of our executive compensation plans, we consider the performance and skills of each of our executives, as well as the compensation paid to executives in similar companies with similar responsibilities. We focus on providing a competitive compensation package that provides significant short-term and long-term incentives for the achievement of measurable corporate objectives. We believe that this approach provides an appropriate blend of short-term and long-term incentives to maximize stockholder value.

The HCM & Compensation Committee uses its judgment to establish a total compensation program for each named executive officer that it believes is appropriate to achieve the goals of our executive compensation program and our corporate objectives. A significant portion of the named executive officers’ total target compensation comprises performance-based bonus opportunities and long-term equity awards to align their incentives with the interests of our stockholders and our corporate goals.

In place of a formal policy for allocating compensation, the HCM & Compensation Committee generally considers each executive officer’s total target direct compensation, which consists of base salary, annual incentives, and long-term equity awards (valued based on an approximation of grant date fair value). The approach includes, as an objective, having the value of long-term equity awards comprise a substantial majority of each executive’s total target direct compensation. The mix of incentives is reviewed and determined regularly by the HCM & Compensation Committee based on the short-term and long-term objectives of the business.

Executive Compensation Decision-Making Process

The Role of the HCM & Compensation Committee. The HCM & Compensation Committee oversees the executive compensation program for our NEOs. The HCM & Compensation Committee consists of independent members of the Board who work closely with an independent consultant and management to examine the effectiveness of the Company’s executive compensation program throughout the year.

The HCM & Compensation Committee meets periodically throughout the year to address its responsibilities, including to manage and evaluate our executive compensation program, and either recommends to the full Board or approves, as applicable, the principal components of compensation (base salary, performance bonus awards, and equity awards) for our executive officers. These executive compensation decisions are generally made on an annual basis; however, decisions may occur at other times for new hires, promotions, or other special circumstances as our HCM & Compensation Committee and/or Board determines appropriate. Prior to March

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2023, all final compensation and equity award decisions regarding NEOs and other executive officers (except for the CEO and Executive Chair) were determined by the members of the full Board, based upon the recommendations of the HCM & Compensation Committee, and the equity awards and compensation of the CEO and Executive Chair were determined by the independent members of the full Board, based upon recommendations of the HCM & Compensation Committee. Following the amendment of our HCM & Compensation Committee Charter in March 2023, the HCM & Compensation Committee is authorized to approve the equity awards and executive compensation of our CEO and other executive officers. The related actions of the HCM & Compensation Committee described in this CD&A, therefore, generally refer to deliberations and recommendations approved by the full Board prior to March 2023 and to approvals by the committee itself thereafter.

The Role of Management. While certain members of management attended meetings of the HCM & Compensation Committee in 2023 by invitation, members of our management team are not present for executive sessions, nor do they participate in discussions about their own pay. The CEO makes recommendations pertaining to the pay of other executives, including our NEOs (other than himself) and executives who are not NEOs, to the HCM & Compensation Committee, providing transparency and oversight. The CEO is not present for the deliberations of, and does not vote on, his own compensation. Independent directors, or the full Board, make all final determinations regarding CEO and NEO compensation.

The Role of the Independent Consultant. The HCM & Compensation Committee engages an independent compensation consultant to provide expertise on competitive pay practices, program design, and an objective assessment of any inherent risks of any programs. The HCM & Compensation Committee has hired Pearl Meyer & Partners, LLC (“Pearl Meyer”) as its independent consultant. Pearl Meyer reports directly to the HCM & Compensation Committee and does not provide any additional services to management or the Board. The HCM & Compensation Committee has analyzed whether the work of Pearl Meyer as the compensation consultant raised any conflict of interest, considering relevant factors in accordance with SEC and other applicable guidelines. Based on its analysis, our HCM & Compensation Committee determined that the work of Pearl Meyer and the individual compensation advisors has conformed to the independence factors and guidance provided by the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010, the SEC and the Nasdaq listing standards.

The Role of Peer Group Companies. The HCM & Compensation Committee strives to set a competitive level of total compensation for each NEO as compared with executive officers in similar positions at peer companies. For purposes of establishing 2023 compensation practices and pay levels, in conjunction with the recommendations of Pearl Meyer, the HCM & Compensation Committee considered publicly available data for a group of peer companies (the “2023 Compensation Peer Group”) as well as industry specific survey data, where appropriate. Peer data is one factor reviewed to determine pay decisions for each NEO. Selection criteria for the 2023 Compensation Peer Group included:

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As part of this review and update, to better reflect growth rate and sector relevance, Duck Creek Technologies, Inc. was removed from the list given a perceived lack of alignment on business fit and financial profile. The members of the 2023 Compensation Peer Group are set forth in the table below:

This market data is not the sole determinant in setting pay levels for our NEOs. Actual pay levels can be above or below the targeted levels depending on factors such as experience, individual or company performance, tenure, employee potential, unique skills, criticality of the position to the Company, and other factors. In general, the HCM & Compensation Committee desires to balance internal and external equity, and reserves the right to use discretion to deviate when necessary to recruit and/or retain the right talent.

2023 EXECUTIVE COMPENSATION PROGRAM

Base Salary

In making base salary decisions, the HCM & Compensation Committee considers the CEO’s recommendations (for NEOs other than the CEO), as well as each NEO’s position and level of responsibility within the Company. The HCM & Compensation Committee considers factors such as competitive market data as well as individual performance, experience, tenure, internal equity, and employee potential without assigning a specific weight to any particular criterion when setting base salaries. Salary levels are reviewed annually as part of our performance review process, and upon promotion, or other material change in job responsibility. Merit-based increases to salaries of the NEOs are based on the HCM & Compensation Committee’s assessment of each individual’s performance, taking into account the recommendations of the CEO (for NEOs other than the CEO).

In early 2023, the HCM & Compensation Committee reviewed the base salaries of our then-serving NEOs and approved merit-based salary increases for Messrs. Musslewhite, Booth, and Mirisola and Ms. Shamsuddin Jensen. In addition, Ms. Shamsuddin Jensen received a further adjustment to bring her salary to a more competitive market level for her experience and role. Mr. Maack did not receive a salary increase for 2023, given his hire date in November 2022.

The 2022 and 2023 base salaries of our named executive officers are reflected in the table below:

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Annual Incentives

In fiscal year 2023, we provided annual cash incentive opportunities to our NEOs under our Bonus Program. We use our Bonus Program to provide annual performance-based cash incentive awards to motivate and reward eligible employees, including the NEOs, for the Company’s achievement of financial objectives, as established by the Board each year.

Target Award Opportunity. Actual payouts depend on the achievement of pre-determined financial and individual performance objectives, as applicable. Annual award opportunities are expressed as a percentage of base salary and were established based on each NEO’s level of responsibility and their ability to impact overall results. The HCM & Compensation Committee also considers market data in setting target award amounts. Award opportunities for 2023 were as follows:

Performance Measures & Weightings. For our NEOs, 75% of the annual incentive award opportunity for 2023 was based on the Company’s financial performance and 25% was based solely on the performance of those individuals against their respective goals, objectives, key performance indicators (“KPIs”), and the Company’s model behaviors. For 2023, NEO individual performance was capped at 100% attainment.

Company Financial Performance. For fiscal 2023, the financial performance objectives under the Bonus Program were equally weighted between the Company’s ARR and the Company’s Adjusted EBITDA Margin. ARR is defined as annualized recurring revenue as of the end of calendar year 2023. Adjusted EBITDA Margin is defined as Adjusted EBITDA as a percentage of the Company’s revenue. Adjusted EBITDA is defined as EBITDA, or earnings before debt-related costs, including interest expense, net and loss on extinguishment of debt, income taxes and depreciation and amortization, adjusted to exclude certain items of a significant or unusual nature, including other income and expense, equity-based compensation, transaction, integration and restructuring expenses and other non-recurring expenses.

The performance measures were established and approved by the HCM & Compensation Committee in early 2023.The HCM & Compensation Committee selected ARR as a Company financial performance measure under the Bonus Program because ARR is a commonly recognized measure of financial and operating performance within our industry and is a key driver of sustained value creation for our stockholders. The HCM & Compensation Committee selected Adjusted EBITDA Margin as the other Company financial performance measure under the Bonus Program to focus on operational efficiency improvements, which we believe are critical to shareholder value creation.

Based on actual performance, the financial performance component of the 2023 annual bonus was eligible for a payout ranging from 0% to 200% of the individual NEO’s bonus target.

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The following table shows the 2023 goals set for ARR and Adjusted EBITDA Margin under the Bonus Program, as well as actual results.

Each year, the HCM & Compensation Committee reviews the financial performance and considers adjustments for items that are not reflective of normal operating performance for that year. These adjustments, if any, are items that the HCM & Compensation Committee believes are fair to both participants and shareholders, encourage appropriate actions that foster the long-term health of the business, and are consistent with the objectives underlying our predetermined performance goals. Such adjustments may consist of the costs and financial effects of restructuring, acquisitions, and dispositions, selected legal costs and settlements, pandemics, and the effects of foreign currency translation. As noted above, during 2023, the HCM & Compensation Committee made an adjustment to the Bonus Program by revising the attainment calculation for Adjusted EBITDA Margin to account for the dilutive impact of the acquisition of Populi. This adjustment was made in consideration of the strategic benefits of completing the acquisition, the inherent difficulty of offsetting the short-term margin impact of a dilutive acquisition that was completed late in the fiscal year and had not been contemplated at the beginning of the year, and the resulting potential detrimental impacts on employee morale and integration success if employees perceived Populi as the reason for missing bonus targets. In early 2024, upon review of final results, the HCM & Compensation Committee applied negative discretion to reduce the level of payout to the Company’s executives in light of overall commercial performance and stock price.

Individual Performance. The 2023 Bonus Program opportunity for each of our NEOs was based 25% on the individual performance against their respective goals, objectives, KPIs, and the Company’s model behaviors. To assess individual performance, the HCM & Compensation Committee reviewed the qualitative goals tied to key strategic initiatives and each NEO’s respective areas of responsibility. None of the goals for 2023 were individually weighted. Based on actual performance, the individual performance component of the 2023 annual bonus was eligible for a payout ranging from 0% to 25% of the individual NEO’s bonus target.

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Actual 2023 Performance and Bonus Payouts. Based on the ARR and Adjusted EBITDA Margin results discussed above, funding for the Company performance portion of each NEO’s applicable award target under the Bonus Program was set at 84.9%.

In evaluating the individual performance components for the NEOs, the HCM & Compensation Committee considered attainment of the individual goals and further considered each NEO’s contribution to the Company’s overall performance, noting that such successes were due in large part to the individual efforts of the NEOs. Based on the foregoing evaluation, the HCM & Compensation Committee approved 100% attainment of the individual performance component of the Bonus Program based on the individual’s results as shown in the table below.

The actual annual incentive awards paid to the NEOs for 2023 were as follows:

Long-Term Equity Incentives

In connection with our IPO, we adopted the 2021 Plan, the purpose of which is to align the interests of eligible participants with our stockholders by providing incentive compensation tied to the Company’s performance. Individual long-term equity incentive grants historically have been determined by the HCM & Compensation Committee and Board based on a number of factors, including current corporate and individual performance, outstanding equity holdings and their retention value and total ownership, historical value of our stock, internal equity among executives, and market data provided by our independent compensation consultant.

2023 Equity Awards. In 2023, the Company granted annual equity compensation awards under the 2021 Plan using a mix of PSUs and RSUs. PSUs are earned and vest only when a specified performance level is achieved, subject to additional time-based vesting thereafter. RSUs vest 25% on the first anniversary of the grant date, followed by quarterly vesting of 6.25% per quarter over the subsequent three years.

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The table below shows the annual long-term incentive awards granted for fiscal year 2023 to each NEO. Target award values were converted to shares based on a 30-day lookback up to and including the closing price of our common stock on the date of grant on February 16, 2023, which was $12.35.

A Closer Look at PSUs. The actual number of 2023 PSUs that are earned is based on the achievement of Net Dollar Retention (“NDR”) and % ARR from Enterprise Customers over a one-year performance period (January 1, 2023 – December 31, 2023). Once the number of PSUs actually earned is determined by the HCM & Compensation Committee, one-third of such shares vest upon the date of such determination, and the remaining two-thirds vests in equal installments on each of February 1, 2025 and February 1, 2026, in each case subject to the recipient’s continued service. The HCM & Compensation Committee selected these performance measures because they represented important drivers of long-term shareholder value. Enterprise Customers represent the majority of our ARR and are a key focus of our go-to-market programs, and NDR is an indicator of the growth in use of our platform by our existing clients. The performance goals applicable to the 2023 PSUs, the respective weightings, and the actual results are set forth in the table below.

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As a result, the following NEOs earned 74.5% of their target PSUs for the 2023 performance cycle (subject to time-based vesting as described above), as follows:

New-Hire RSU Grant. As noted above, in connection with her appointment to the role of Chief Revenue Officer, Ms. Lazorchak received a grant of 385,695 RSUs on November 1, 2023, which will vest 25% on November 1, 2024, followed by quarterly vesting of 6.25% per quarter until fully vested over the subsequent three years. The HCM & Compensation Committee determined that this new-hire grant was appropriate in order to address the value of unvested equity compensation from Ms. Lazorchak’s prior employer.

OTHER PRACTICES, PROGRAMS AND GUIDELINES

Stock Ownership Guidelines

At the recommendation of our HCM & Compensation Committee, our Board adopted minimum stock ownership guidelines (the “Director Holding Guidelines”) applicable to non-employee directors in May 2022. In March 2023, at the recommendation of our HCM & Compensation Committee, the Board adopted similar guidelines to apply to our executive officers, including our NEOs and our Executive Chairman (the “Executive Holding Guidelines”). The Executive Holding Guidelines provide that such persons are required to achieve, and maintain, ownership of our common stock valued at the following multiple of their annual base salary, as applicable:

Each such executive officer is expected to meet the applicable guideline level within five years after the later of adoption of the Executive Holding Guidelines or the person becoming subject to such guidelines and to maintain such levels for so long as they remain subject to the Executive Holding Guidelines. Executive officers who have not yet satisfied their applicable guideline level are required to retain 25% of the shares of our common stock that they receive as the result of the exercise, vesting or payment of any equity awards granted to them until they achieve compliance. Shares counting toward meeting the requisite guideline levels include outstanding shares of our Class A common stock, vested and unvested LLC Units (as defined below), and vested and unvested time-based RSUs.

For a description of the Director Holding Guidelines applicable to our non-employee directors see “Director Compensation — Director Stock Ownership Guidelines.”

Other Benefits and Perquisites

All of our NEOs are eligible to participate in our employee benefit plans, including medical, dental, vision, and life insurance plans, in each case on the same basis as all of our other employees, except that we pay the

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employee portion of the premiums for medical, dental and vision coverage on behalf of our NEOs. We also pay the premiums for the life, disability, accidental death, and dismemberment insurance for all employees, including our NEOs. We otherwise generally do not provide perquisites or personal benefits.

Retirement Plan

Our NEOs are eligible to participate in a tax-qualified defined contribution plan, the Definitive Healthcare LLC 401(k) Profit Sharing Plan (the “401(k) Plan”), which provides U.S. employees with an opportunity to save for retirement on a tax advantaged basis. Eligible employees may defer eligible compensation on a pre-tax or after-tax (“Roth”) basis, up to the statutorily prescribed annual limits on contributions under the Internal Revenue Code of 1986, as amended (the “Code”). We may make matching and discretionary profit-sharing contributions for the plan year ending December 31, based on employee deferrals for the plan year. For 2023, we provided matching contributions equal to 100% of the participants’ salary deferrals up to 3% of their compensation and 50% of their salary deferrals on the following 2% of compensation. We did not make any discretionary profit-sharing contributions to the 401(k) Plan for the 2023 plan year. The 401(k) Plan is intended to be qualified under Section 401(a) of the Code with the 401(k) Plan’s related trust intended to be tax exempt under Section 501(a) of the Code. As a tax-qualified retirement plan, contributions to the 401(k) Plan (except for Roth contributions) and earnings on those contributions are not taxable to the employees until distributed from the 401(k) Plan.

Compensation Recovery

In September 2023, our HCM & Compensation Committee approved a new Incentive Compensation Recoupment Policy (the “Clawback Policy”), effective October 2, 2023, that is designed to comply with, and will be interpreted in a manner consistent with, Section 10D of the Exchange Act and the applicable rules of Nasdaq. Under the Clawback Policy, in the event of an accounting restatement due to the Company’s material noncompliance with any financial reporting requirement under applicable securities laws, including any required accounting restatement to correct a material error in previously issued financial statements, or that would result in a material misstatement if the error were corrected in the current period or left uncorrected in the current period, the Company must recover erroneously awarded performance-based compensation previously paid to our executive officers in accordance with the terms of the Clawback Policy. Additionally, under the Clawback Policy, we are prohibited from indemnifying any executive officer or former executive officer against the loss of erroneously awarded performance-based compensation and from paying or reimbursing an executive officer for purchasing insurance to cover any such loss.

Anti-Hedging & Pledging Policies

We prohibit directors, officers, and employees from trading in options, warrants, puts and calls, or similar instruments on the Company’s securities or short selling such securities. In addition, directors, officers, and employees are prohibited from purchasing any financial instrument or entering into any transaction that is designed to hedge, establish downside price protection, or otherwise offset declines in the market value of the Company’s securities, including puts, calls, prepaid variable forward contracts, equity swaps, collars, exchange funds (excluding broad-based index funds), and other financial instruments that are designed to or have the effect of hedging or offsetting any decrease in the market value of the Company’s securities. Our insider trading policy also prohibits directors, officers, and employees from pledging, hypothecating, or otherwise encumbering the Company’s securities as collateral for indebtedness.

Employment Agreements and Offer Letters

We have entered into employment agreements or offer letters with each of our NEOs upon their joining the Company. Each of these agreements established the named executive officer’s starting base salary, initial target annual bonus opportunity, and initial equity grant. NEOs’ base salaries, annual bonus opportunities and any equity awards are reviewed upon hiring, as well as annually, by the HCM & Compensation Committee; the

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amounts effective for fiscal year 2023 are described above in this CD&A. The agreements are summarized below under “—Employment Agreements.” We intend to periodically review the level of benefits in these agreements.

Severance and Change in Control Benefits

We provide our NEOs with certain severance and change in control protections in their employment agreements and/or offer letters in order to attract and retain an appropriate caliber of talent for such positions, as well as through our Change in Control and Non-Change in Control Severance Plans. These protections are summarized below under the heading “Employment and Severance Agreements” in the narrative to the Potential Payments upon Termination or Change-in-Control Table below.

Insider Trading Policy

Pursuant to our insider trading policy, no director, officer, or other employee of the Company who is aware of material non-public information related to the Company may, directly or indirectly, through family members or other persons or entities, buy or sell Company securities. In addition, if a director, officer, or other employee of the Company learns of material non-public information about a company with which the Company does business, including a customer or supplier, our insider trading policy prohibits trading in, taking advantage of, or sharing information about that company’s securities until the information is made public or is no longer material.

Compensation Risk Assessment

Our HCM & Compensation Committee is responsible for evaluating, recommending, and approving executive officer compensation arrangements, plans, policies, and programs and performs an annual assessment of the risk they impose. In consultation with management, our HCM & Compensation Committee assessed our executive officer compensation arrangements, plans, policies, and programs and concluded that they do not create risks that are reasonably likely to have a material adverse effect on our company. This risk assessment included, among other things, a review of the extent to which the Company’s compensation policies and practices could lead to excessive risk-taking behavior, the manner in which any risks arising out of the Company’s compensation policies and practices are monitored and mitigated and any adjustments that may be necessary to address changes in the Company’s risk profile.

TAX AND ACCOUNTING CONSIDERATIONS

As a general matter, the HCM & Compensation Committee reviews and consider the various tax and accounting implications of compensation programs we utilize.

Code Section 162(m)

Under Section 162(m) of the Code (“Section 162(m)”), compensation paid to each of the Company’s “covered employees” that exceeds $1 million per taxable year is generally non-deductible. Although the HCM & Compensation Committee will consider tax implications as one factor in determining executive compensation, the HCM & Compensation Committee also looks at other factors in making its decisions and retains the flexibility to provide compensation for the Company’s named executive officers in a manner consistent with the goals of the Company’s executive compensation program and the best interests of the Company and its stockholders, which may include providing for compensation that is not deductible by the Company due to the deduction limit under Section 162(m). The HCM & Compensation Committee also retains the flexibility to modify compensation that was initially intended to be exempt from the deduction limit under Section 162(m) if it determines that such modifications are consistent with the Company’s business needs.

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Code Section 409A

Section 409A of the Code (“Section 409A”) requires that “nonqualified deferred compensation” be deferred and paid under plans or arrangements that satisfy the requirements of the statute with respect to the timing of deferral elections, timing of payments and certain other matters. Failure to satisfy these requirements can expose employees and other service providers to accelerated income tax liabilities, penalty taxes and interest on their vested compensation under such plans. Accordingly, as a general matter, it is our intention to design and administer our compensation and benefits plans and arrangements for all of our employees and other service providers, including our NEOs, so that they are either exempt from, or satisfy the requirements of, Section 409A.

Code Section 280G

Section 280G of the Code (“Section 280G”) disallows a tax deduction with respect to excess parachute payments to certain executives of companies which undergo a change of control. In addition, Section 4999 of the Code (“Section 4999”) imposes a 20% excise tax on the individual with respect to the excess parachute payment. Parachute payments are compensation linked to or triggered by a change of control and may include, but are not limited to, bonus payments, severance payments, certain fringe benefits, and payments and acceleration of vesting from long-term incentive plans including stock options, restricted stock, and other equity-based compensation. Excess parachute payments are parachute payments that exceed a threshold determined under Section 280G based on the executive’s prior compensation. In approving the compensation arrangements for our named executive officers, the HCM & Compensation Committee considers all elements of the cost to the Company of providing such compensation, including the potential impact of Section 280G. However, the HCM & Compensation Committee may, in its judgment, authorize compensation arrangements that could give rise to loss of deductibility under Section 280G and the imposition of excise taxes under Section 4999 when it believes that such arrangements are appropriate to attract and retain executive talent.

Accounting for Stock-Based Compensation

We follow the Financial Accounting Standards Board’s Accounting Standards Codification Topic 718 (“ASC Topic 718”) for our stock-based compensation awards. ASC Topic 718 requires companies to calculate the grant date “fair value” of their stock-based awards using a variety of assumptions. ASC Topic 718 also requires companies to recognize the compensation cost of their stock-based awards in their income statements over the period that an employee is required to render service in exchange for the award. Grants of restricted stock units under our equity incentive award plans are accounted for under ASC Topic 718. The HCM & Compensation Committee considers the accounting implications of significant compensation decisions, especially in connection with decisions that relate to our equity award programs. As accounting standards change, we may revise certain programs to appropriately align accounting expenses of our equity awards with our overall executive compensation philosophy and objectives.

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REPORT OF THE HUMAN CAPITAL MANAGEMENT AND COMPENSATION COMMITTEE

The information contained in this report is not to be deemed to be “soliciting material” or to be “filed” with the SEC, or subject to Regulation 14A of the Exchange Act or to the liabilities of Section 18 of the Exchange Act, nor is such information to be incorporated by reference into any future filing under the Securities Exchange Act of 1933, as amended, or the Exchange Act, except to the extent that we specifically incorporate it by reference into such filing.

The HCM & Compensation Committee operates pursuant to a charter which is reviewed annually by the HCM & Compensation Committee. Additionally, a brief description of the primary responsibilities of the HCM & Compensation Committee is included in this Proxy Statement under “The Board of Directors and Certain Governance Matters—Board Committees and Meetings—HCM & Compensation Committee.” Under the HCM & Compensation Committee charter, the HCM & Compensation Committee’s responsibilities include evaluating, recommending, and approving executive officer compensation arrangements, plans, policies, and programs.

The HCM & Compensation Committee has reviewed and discussed the Compensation Discussion and Analysis with the Company’s management and, based on such review and discussion, has recommended to the Board that the Compensation Discussion and Analysis be included in this Proxy Statement.

Submitted by the HCM & Compensation Committee of the Company’s Board of Directors:

Jill Larsen, Chair

Jeff Haywood

Lauren Young

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EXECUTIVE COMPENSATION TABLES

Summary Compensation Table

The following table sets forth certain information regarding the total compensation awarded to, earned by, or paid to our NEOs in fiscal years 2023, 2022, and 2021. We did not issue stock options to our NEOs during any such period.

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Grant of Plan-Based Awards Table

The following table provides information regarding grants of plan-based awards to our NEOs during the year ended December 31, 2023.

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Narrative Discussion of the Summary Compensation Table and Grants of Plan-Based Awards Table

In fiscal 2023, we compensated our NEOs primarily through a combination of base salary, annual cash incentive awards and, for certain NEOs, equity awards. Our NEOs are also entitled to certain other benefits, subject to their enrollment, including a 401(k) plan with matching contributions, medical, dental, vision, life, accidental death and dismemberment, short-term disability, and long-term disability insurance. The components of our fiscal 2023 compensation program are described in more detail under “Compensation Discussion and Analysis” above.

Employment Agreements

Robert Musslewhite

As disclosed in our current report on Form 8-K, filed with the SEC on January 16, 2024, Mr. Musslewhite stepped down as the Company’s Chief Executive Officer and as a member of the Company’s Board of Directors, effective January 16, 2024. See “—Potential Payments upon Termination or Change of Control—Employment Arrangements—Robert Musslewhite” below.

Richard Booth

We entered into an employment agreement with Mr. Booth (the “Booth Employment Agreement”) on January 29, 2021. The Booth Employment Agreement provides for at-will employment, and further provides that Mr. Booth will receive a base salary, which is reviewed on an annual basis by the HCM and Compensation Committee to determine whether it should be increased or otherwise modified. See the “Summary Compensation Table” above for Mr. Booth’s base salary for fiscal 2023. The Booth Employment Agreement also provides that Mr. Booth is eligible to receive a cash bonus based on the Company achieving specified performance targets and other requirements which will be determined reasonably and in good faith on an annual basis for the corresponding year by the Chief Executive Officer and the HCM and Compensation Committee. Mr. Booth’s target annual incentive bonus for 2023 was equal to 57.5% of his base salary.

In addition to the above, Mr. Booth participates in the employee benefits programs offered by us to our similarly-situated employees. The Booth Employment Agreement provides for the reimbursement of 100% of all health insurance premiums for Mr. Booth if enrolled in a Company sponsored health plan. The cost of the health insurance premiums reimbursed to Mr. Booth are reflected in the “Summary Compensation Table” above in the “All Other Compensation” column.

Jonathan Maack

In connection with Mr. Maack’s appointment as President, we entered into an employment agreement with Mr. Maack, dated September 22, 2022 (the “Maack Employment Agreement”). The Maack Employment

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Agreement provides for at-will employment, and further provides that Mr. Maack is entitled to (i) an annual base salary of $400,000, and (ii) an annual bonus equal to, in the sole discretion of the HCM & Compensation Committee, an amount up to 70% of Mr. Maack’s base salary, based on the Company’s achieving specified performance targets and other requirements determined annually by the Chief Executive Officer of the Company and the Board. The Maack Employment Agreement also provided for an initial grant (the “Initial RSU Grant”) of 546,303 RSUs, which vest (i) 25% on November 3, 2023 and (iii) thereafter, 6.25% every three months for the next three years until fully vested, in each case subject to Mr. Maack’s continued Service (as defined in the 2021 Plan) through each vesting date. In addition, the Maack Employment Agreement provides that Mr. Maack will be eligible for an annual equity award in 2024 (the “2024 Award”) pursuant to the 2021 Plan, upon such terms and conditions as are determined by the HCM & Compensation Committee in its sole discretion, provided that management will recommend to the HCM & Compensation Committee that the 2024 Award have a target grant value of at least $2 million and that any time-based component thereof vest consistent with the vesting schedule of the Initial RSU Grant.

Pursuant to the Maack Employment Agreement, Mr. Maack is eligible to participate in the Company’s benefit plans that are generally available to the Company’s executive employees and for reimbursement of certain expenses, including a one-time lump-sum relocation payment of $330,000, which is subject to repayment requirements should Mr. Mack’s employment terminate within 24 months of September 22, 2022. Mr. Maack is also eligible for reimbursement of 100% of all health insurance premiums for Mr. Maack if enrolled in a Company sponsored health plan. The cost of the health insurance premiums reimbursed to Mr. Maack is reflected in the “Summary Compensation Table” above in the “All Other Compensation” column.

Kate Shamsuddin Jensen

In connection with Ms. Shamsuddin Jensen’s initial employment, we entered into an offer letter with her, dated February 3, 2015 (the “Jensen Offer Letter”). The Jensen Offer Letter provides for at-will employment and a starting annual base salary of $115,000. It further provides for a corporate bonus based on the Company’s performance, which is pro-rated for a partial work year and will only be paid to Ms. Shamsuddin Jensen if she is employed at the time of payment of the bonus. The Jensen Offer Letter also provides for eligibility to participate in the benefits plans offered to Company employees.

Carrie Lazorchak

In connection with her initial employment, we entered into an employment agreement with Ms. Lazorchak dated October 2, 2023 (the “Lazorchak Employment Agreement”). The Lazorchak Employment Agreement provides for at-will employment, and further provides that Ms. Lazorchak is entitled to (i) an annual base salary of $400,000 for 2023 (to be determined by the HCM & Compensation Committee for future years), (ii) an annual bonus equal to at least 75% of Ms. Lazorchak’s base salary at “target” (with 2023 being pro-rated based upon Ms. Lazorchak’s start date), and (iii) during 2024, $50,000 per calendar quarter as advance payment against Ms. Lazorchak’s 2024 cash bonus opportunity (with provisions for adjustment and recoupment in the event actual 2024 cash bonus attainment is less than the amount of advance payments made during 2024). In addition, pursuant to the Lazorchak Employment Agreement, Ms. Lazorchak received an initial grant (the “Initial Lazorchak Grant”) with a target value of $2,750,000 of RSUs pursuant to the Company’s 2023 Inducement Plan, with the actual number of shares determined based on the average closing price of the Company’s Class A common stock over the thirty trading days immediately preceding (and not including) her start date. Subject to Ms. Lazorchak’s continued employment through each vesting date, the Initial Lazorchak Grant will vest as follows: (i) 25% of the shares will vest on the 1-year anniversary of Ms. Lazorchak’s start date; (ii) quarterly vesting of 6.25% of the shares subject to the Initial Lazorchak Grant per quarter until fully vested over the subsequent three years.

Pursuant to the Lazorchak Employment Agreement, Ms. Lazorchak is eligible to participate in the Company’s benefit plans that are generally available to the Company’s executive employees and for reimbursement of

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certain expenses, including coverage of 100% of all health insurance premiums for Ms. Lazorchak if enrolled in a Company sponsored health plan. The cost of the health insurance premiums paid on behalf of Ms. Lazorchak are reflected in the “Summary Compensation Table” above in the “All Other Compensation” column.

Joseph Mirisola

Mr. Mirisola’s employment with the Company ended effective December 31, 2023. See “—Potential Payments upon Termination or Change of Control—Employment Arrangements—Joseph Mirisola” below.

Equity Compensation

In connection with our IPO, we adopted the 2021 Plan, effective as of September 14, 2021. Additionally, our HCM & Compensation Committee approved the 2023 Inducement Plan on September 5, 2023 pursuant to Rule 5635(c)(4) of the Nasdaq Listing Rules. The terms of the 2023 Inducement Plan substantially mirror those of the 2021 Plan. The purpose of each of the 2021 Plan and 2023 Inducement Plan is to align the interests of eligible participants with our stockholders by providing incentive compensation tied to the Company’s performance.

Prior to our IPO, we granted equity awards in the form of Class B Units (“Class B Units”) under the AIDH Topco, LLC 2019 Equity Incentive Plan (the “2019 Plan”). In connection with the Reorganization Transactions (as defined below), unvested Class B Units held directly by employees of the Company or indirectly through AIDH Management Holdings, LLC were exchanged for (i) unvested LLC Units of AIDH Management Holdings, LLC (which correspond on a one-for-one basis to LLC Units in AIDH TopCo, LLC) or (ii) in the case of Mr. Krantz, unvested LLC Units in AIDH TopCo, LLC, in each such case based on their respective participation thresholds and the IPO price of $27.00 per share. All such unvested LLC Units are subject to time-based vesting. The Company no longer grants any awards under the 2019 Plan, though previously granted awards under the 2019 Plan remain outstanding and governed by the 2019 Plan. Until redeemed or exchanged, each LLC Unit is paired with one share of the Company’s Class B Common Stock. Unless otherwise indicated or the context so requires, awards of “LLC Units” refer to LLC Units of AIDH TopCo held directly, in the case of Mr. Krantz, or indirectly through AIDH Management Holdings, LLC, in the case of our other directors and executive officers. For additional information with respect to the LLC Units, see “Certain Relationships and Related Person Transactions—Amended Definitive OpCo LLC Agreement” below.

Outstanding Equity Awards at Fiscal Year-End

The following table sets forth certain information with respect to outstanding equity awards held by our NEOs as of December 31, 2023. The Company did not have any outstanding stock options, vested or unvested, as of December 31, 2023.

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Option Exercises and Stock Vested During Fiscal 2023

The following table shows the number of shares of our Class A common stock acquired on vesting of stock awards granted to our NEOs and the aggregate value realized upon such vesting during the year ended December 31, 2023. The Company did not have any outstanding stock options, vested or unvested, during the year ended December 31, 2023.

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Potential Payments Upon Termination or Change-In-Control

In the event of a qualifying termination of employment and/or the occurrence of a change in control of the Company, certain of our NEOs are entitled to payments and benefits under their employment agreements, our severance plans, and/or their outstanding equity incentive awards. For a detailed summary of these payments and benefits, see the narrative description following the table below.

The following table sets forth the payments that each of our NEOs (other than Mr. Mirisola) would have been entitled to in the circumstances described. The payments and benefits set forth below are estimated assuming that the relevant event happened on December 31, 2023. Amounts shown do not include (i) accrued but unpaid salary or bonus and vested benefits and (ii) other benefits earned or accrued by the NEO during his or her tenure that are available to all salaried employees and that do not discriminate in scope, terms, or operation in favor of executive officers.

Mr. Mirisola’s employment with the Company ended effective December 31, 2023 and he is not included in the table below. Amounts actually paid to Mr. Mirisola in connection with his departure from the Company are reflected in the Summary Compensation Table and are described under the heading “—Joseph Mirisola” below.

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Equity Arrangements

Pursuant to the 2021 Plan, if either of Mr. Booth, or Ms. Shamsuddin Jensen’s service is terminated upon or within 24 months following a “Change in Control” (as defined in the 2021 Plan) without “Cause” (as defined in the 2021 Plan) or upon other circumstances as determined by the HCM and Compensation Committee, the unvested portion (if any) of all outstanding RSUs held by such executive will immediately vest and be paid in full upon termination, with any applicable performance conditions deemed achieved (i) for any completed performance period, based on actual performance, or (ii) for any partial or future performance period, at the greater of the target level or actual performance, in each case as determined by the HCM and Compensation Committee.

Pursuant to the 2023 Inducement Plan, if Ms. Lazorchak’s service is terminated upon or within 24 months following a “Change in Control” (as defined in the 2023 Inducement Plan) without “Cause” (as defined in the 2023 Inducement Plan) or upon other circumstances as determined by the HCM and Compensation Committee, the unvested portion (if any) of all outstanding RSUs held by such executive will immediately vest and be paid in full upon termination, with any applicable performance conditions deemed achieved (i) for any completed performance period, based on actual performance, or (ii) for any partial or future performance period, at the greater of the target level or actual performance, in each case as determined by the HCM and Compensation Committee.

Pursuant to the 2019 Plan, we granted Class B Units to Mr. Musslewhite, Mr. Booth, Mr. Mirisola, and Ms. Shamsuddin Jensen, which have been converted into LLC Units in AIDH Management Holdings, LLC as described above under “Narrative Discussion of the Summary Compensation Table and Grants of Plan-Based Awards Table – Equity Compensation” and “Compensation Discussion and Analysis – Components of Our Executive Compensation Program – Equity Compensation”. Upon the consummation of a “Change in Control”, as defined in and pursuant to the relevant award agreement, all of the unvested LLC Units held by Mr. Booth, Mr. Mirisola, and Ms. Shamsuddin Jensen will become vested as of immediately prior to such Change in Control, subject to such executive’s continued service on the date of the Change in Control.

The acceleration of Mr. Musslewhite’s, Mr. Maack’s, and Mr. Booth’s equity awards in connection with termination or change of control is further provided for pursuant to such executives’ employment agreements, as described below.

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Employment Arrangements

Robert Musslewhite

If we terminated Mr. Musslewhite’s employment without “Cause” (as defined below and other than as a result of death or Disability (as defined in the Employment Agreement)) or Mr. Musslewhite terminated his employment for “Good Reason” (as defined below) then, subject to his execution of a general release of claims and certain other conditions set forth in the Musslewhite Employment Agreement, we were required to provide Mr. Musslewhite with (i) continuation of regular payments of base salary for a period of twelve months; (ii) payment of the annual bonus to be earned by Mr. Musslewhite during the twelve month period following the date of termination of employment at the greater of “target” or the average bonus paid over the prior two years, payable in a lump sum; (iii) acceleration of the vesting of all forms of time-based equity awarded to Mr. Musslewhite by the Company at any time, that would otherwise have vested during the twelve-month period following the termination date; (iv) for performance-based equity awards, to the extent performance goals are capable of being achieved during the twelve-month period following the termination date, such equity awards shall remain outstanding and eligible to vest during such twelve month period and, if such performance goals are not achieved, shall be forfeited; (v) payment for twelve months of COBRA coverage, if applicable; and (vi) the annual bonus earned with respect to the prior fiscal year.

If during a Change of Control Period (as defined in the Musslewhite Employment Agreement), Mr. Musslewhite’s employment was terminated without Cause, or Mr. Musslewhite terminated his employment with Good Reason, then we were required to provide Mr. Musslewhite with (i) continuation of regular payments of base salary for a period of eighteen months from the date of termination of employment; (ii) payment of 1.5 times the annual bonus at a level equal to the greater of the annual target bonus or the average of the bonuses paid in the last two calendar years (if such history exists) to be earned by Mr. Musslewhite during the twelve month period following the date of termination of employment, payable in a lump sum; (iii) acceleration of the vesting of all forms of equity awarded to Mr. Musslewhite by the Company or its affiliates at any time, treating for such purposes any performance-based equity awards as achieved at the greater of (A) actual achievement of the performance goal (if capable of being measured immediately prior to the time of the occurrence of the Change in Control or Mr. Musslewhite’s termination of employment) or (B) target; and (iv) payment for eighteen months of COBRA coverage, if applicable.

The Musslewhite Employment Agreement included customary provisions requiring confidentiality, assignment of inventions, non-competition, and nonsolicitation of our employees during employment and one year thereafter.

For purposes of the Musslewhite Employment Agreement, “Cause” means, with respect to Mr. Musslewhite, (i) commission of, or pleading guilty or no contest to, a felony, a gross misdemeanor, or any crime involving moral turpitude; (ii) any unlawful act which is materially injurious or detrimental to the reputation or financial interests of the Company or its affiliates; (iii) theft of property of the Company or its affiliates or falsification of documents of the Company or its affiliates or dishonesty in their preparation; (iv) breach of any material provision of any written policy, handbook, or code of conduct of the Company or its affiliates (including, without limitation, any provision pertaining to harassment, discrimination, or retaliation), or any material provision of any agreement with the Company or its affiliates, including any non-competition, non-solicitation, or confidentiality provisions, or any other similar restrictive covenants to which Mr. Musslewhite is or may become a party with the Company or its affiliates.

For purposes of the Musslewhite Employment Agreement, “Good Reason” means without the written consent of Mr. Musslewhite: (i) a material diminution (of 10% or more) of the Base Salary or target Bonus; (ii) any material breach by the Company of any written agreement between Mr. Musslewhite and the Company or its affiliates; (iii) the Company materially changes the location of Mr. Musslewhite’s working arrangements as in effect on May 4, 2022; or (iv) a material diminution of Mr. Musslewhite’s duties, title, authority, or responsibilities (to include any change in reporting that results in Mr. Musslewhite not reporting to the Board), provided that no condition set forth in the preceding (i), (ii), (iii), or (iv) will be deemed good reason unless the Company fails to

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cure in all material respects the condition(s) giving rise to good reason within 30 days from the date on which Mr. Musslewhite notifies the Company, in writing, of such condition(s).

On January 16, 2024, Mr. Musslewhite stepped down as our Chief Executive Officer. Mr. Musslewhite’s departure constituted a termination of employment without “cause” for purposes of the Musslewhite employment agreement and any other employment, equity compensation or benefit agreement, plan or arrangement of the Company and its subsidiaries to which Mr. Musslewhite is a party or otherwise participated. In addition, in January 2016, we entered into a Separation Agreement and Release of Claims with Mr. Musslewhite, pursuant to which we credited him with an additional three months of accelerated vesting with respect to his outstanding time-based equity awards (for a total of 15 months) and agreed to reimburse him up to $15,000 for legal fees incurred by him in connection with the Separation Agreement.

Richard Booth

If we terminate Mr. Booth’s employment without Cause (as defined below) and other than as a result of death or Disability (as defined in the Booth Employment Agreement)), or Mr. Booth terminates his employment for “Good Reason,” (as defined below) then we must provide Mr. Booth with (i) continuation of regular payments of salary at the rate in effect on the date of termination for a period of twelve months from the date of termination of employment, payable in accordance with our regular payroll schedule; (ii) payment of the on-target bonus to be earned by Mr. Booth during the twelve month period following the date of termination of employment, within 30 days following the date of termination; and (iii) acceleration of the vesting of all time-based stock options, restricted stock shares, LLC Units, profit interests, or other forms of equity awarded to Mr. Booth by the Company at any time, that would otherwise have vested during the twelve-month period following the termination date.

The Booth Employment Agreement includes customary confidentiality provisions, as well as provisions relating to assignment of inventions, and a one-year post-termination non-solicitation of our employees.

For purposes of the Booth Employment Agreement, “Cause” means that the Mr. Booth has: (i) knowingly and willfully breached any fiduciary duty or any material legal contractual obligation to us, which breach, if curable, is not cured within 15 days after written notice to Mr. Booth thereof or, if cured, recurs; (ii) failed to follow any reasonable directive of the Board, which failure, if curable, is not cured within 15 days after written notice to Mr. Booth thereof or, if cured, recurs; (iii) engaged in gross negligence, fraud, embezzlement, acts of dishonesty or knowing and willful conflict of interest relating to the affairs of the Company or any of our affiliates; (iv) been convicted of or pleaded nolo contendere to (A) any misdemeanor relating to the affairs of the Company or any of our affiliates or (B) any felony (excluding any motor vehicle offense for which a non-custodial sentence is received); or (v) engaged in a willful violation of any federal or state securities laws.

For purposes of the Booth Employment Agreement, “Good Reason” means: (a) a material diminution (of 10% or more) of Mr. Booth’s base salary or target bonus (i.e. the size of the target bonus that Mr. Booth has the opportunity to earn) unless Mr. Booth consents to such reduction; or (b) any material breach by the Company of any written agreement between us and Mr. Booth; or (c) a relocation of the principal office of the Company more than thirty (30) miles; (d) a material diminution of the duties, title, authority or responsibilities of Mr. Booth other than those duties, titles, authority, or responsibilities that are by their nature or specifically identified as temporary; and (e) the failure of the Company to obtain the assumption in writing of its obligations to fully perform the Booth Employment Agreement by any successor to all or substantially all of the of the assets of the Company within 15 days after request by Mr. Booth following a merger, consolidation, sale, or similar transaction, provided that no condition set forth in the preceding will be deemed good reason unless the Company cures the condition(s) giving rise to good reason within 30 days from the date on which Mr. Booth notifies the Company, in writing, of such condition(s).

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Jonathan Maack

If we terminate Mr. Maack’s employment without Cause (as defined below) and other than as a result of death or Disability (as defined in the Maack Employment Agreement) or Mr. Maack terminates his employment for Good Reason (as defined below) then, subject to his execution of a general release of claims and certain other conditions set forth in the Employment Agreement, we must provide Mr. Maack with (i) continuation of regular payments of base salary for a period of twelve months; (ii) payment of any annual bonus for a prior fiscal year to the extent earned but not previously paid, plus a lump-sum payment of the annual bonus to be earned by Mr. Maack during the twelve month period following the date of termination of employment at the greater of “target” or the average bonus paid over the prior two years (if such history exists); (iii) accelerated vesting of all forms of equity awarded to Mr. Maack by the Company at any time that are subject to time-based vesting and would otherwise have vested during the twelve-month period following the termination date; and (iv) payment for twelve months of COBRA coverage, if applicable.

If during a Change of Control Period (as defined in the Maack Employment Agreement), Mr. Maack’s employment is terminated without Cause, or Mr. Maack terminates his employment for Good Reason, then we must provide Mr. Maack with (i) continuation of regular payments of base salary for a period of eighteen months from the date of termination of employment; (ii) payment of any annual bonus for a prior fiscal year to the extent earned but not previously paid, plus a lump-sum payment of 1.5 times the greater of the target annual bonus to be earned by Mr. Maack in the year of termination or the average of the bonuses paid in the last two calendar years (if such history exists); (iii) acceleration of the vesting of all forms of equity awarded to Mr. Maack by the Company at any time; and (iv) payment for eighteen months of COBRA coverage, if applicable.

The Maack Employment Agreement includes customary confidentiality provisions, as well as provisions relating to assignment of inventions, and a one-year post-termination non-solicitation of our employees.

For purposes of the Maack Employment Agreement, “Cause” means, with respect to Mr. Maack, (i) commission of or indictment for, pleading guilty or no contest to, a felony, a gross misdemeanor, or any crime involving moral turpitude; (ii) any unlawful act which is materially injurious or detrimental to the reputation or financial interests of the Company or its affiliates; (iii) theft of property of the Company or its affiliates or falsification of documents of the Company or its affiliates or dishonesty in their preparation; or (iv) breach of any material provision of any agreement with the Company or its affiliates, including any non-competition, non-solicitation, or confidentiality provisions, or any other similar restrictive covenants to which Mr. Maack is or may become a party with the Company or its affiliates. To the extent any breach set forth in this definition of cause can be cured, the Company shall provide written notice to Mr. Maack identifying the breach and Mr. Maack shall have thirty (30) calendar days to cure the breach.

For purposes of the Maack Employment Agreement, “Good Reason” means, without Mr. Maack’s written consent, (a) a material diminution (of 10% or more) of the base salary or target annual bonus (i.e. the size of the target annual bonus that Mr. Maack has the opportunity to earn); or (b) any material breach by the Company of any material written agreement between Mr. Maack and the Company; (c) a material relocation of Mr. Maack’s principal office of employment; or (d) a material diminution of the duties, title, authority, or responsibilities of Mr. Maack (to include any change in reporting that results in Mr. Maack not reporting to the CEO of the Company or to the Board) other than those duties, titles, authority, or responsibilities that are by their nature or specifically identified as temporary, provided that no condition set forth in the preceding (a), (b), (c) or (d) will be deemed good reason unless the Company fails to cure the condition(s) giving rise to good reason within 30 days from the date on which Mr. Maack notifies the Company, in writing, of such condition(s) (the “Cure Period”), and Mr. Maack resigns from employment within thirty (30) days following the expiration of the Cure Period.

Joseph Mirisola

In connection with Mr. Mirisola’s departure, Mr. Mirisola and the Company entered into a Separation Agreement dated October 2, 2023 (the “Mirisola Separation Agreement”). The Mirisola Separation Agreement provides, in

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exchange for a release of claims and agreement to certain restrictive covenants, that Mr. Mirisola receive, effective as of his final date of employment on December 31, 2023: (a) a lump-sum cash payment equal to 9 months of his then-current base salary; (b) eligibility to receive his cash bonus for 2023 if, when, and as such bonus attainment is determined by the HCM & Compensation Committee for executives; (c) COBRA premium payments for up to 9 months were offered to Mr. Mirisola, although he was not enrolled in the Company’s health insurance plans prior to his departure; (d) 6 months of outplacement services; and (e) acceleration of 102,523 total shares of Common Stock subject to time-based restricted stock units or LLC Units (equal to what would have otherwise vested in the 9 months following Mr. Mirisola’s last date of employment). With respect to the 2023 cash bonus referenced in the preceding sentence, please refer to “Compensation Discussion and Analysis – 2023 Executive Compensation Program – Annual Incentives” for discussion of amounts earned and paid. Mr. Mirisola waived benefits coverage and thus the Company did not make any payments with respect to COBRA premiums referenced in clause “(c)” above.

Non-Change in Control Severance Plan

Ms. Shamsuddin Jensen and Ms. Lazorchak are eligible to participate in our Severance Plan for Executives (the “Severance Plan”) as Eligible Employees (as defined in the Severance Plan). If we terminate their employment without Cause (as defined below), and other than as a result of death or Disability (as defined in the Severance Plan), then, subject to execution of a general release of claims and certain other conditions set forth in the Severance Plan, such Eligible Employee is entitled to (i) continuation of regular payments of base salary for a period of (a) nine months, in the case of an Eligible Employee who has been continuously employed by the Company or a subsidiary for two years or more (a “Tenured Employee”), or (b) six months, in the case of an Eligible Employee who has been continuously employed by the Company or a subsidiary for less than two years (a “Non-Tenured Employee”); (ii) payment of their current year annual bonus at “target” performance levels on a pro-rated basis, but only if their Separation Date (as defined in the Severance Plan) occurs on or after July 1 of a calendar year; (iii) accelerated vesting of any equity awards held by them as of the Separation Date and which vest solely based on continued service with the Company, to the extent such awards would have vested had they remained employed by the Company through (a) the nine-month period following their Separation Date, in the case of a Tenured Employee, or (b) the six-month period following their Separation Date, in the case of a Non-Tenured Employee; and (iv) if applicable, payment for up to (a) nine months of COBRA coverage, in the case of a Tenured Employee, or (b) six months of COBRA coverage, in the case of a Non-Tenured Employee.

An Eligible Employee under the Severance Plan will not be eligible for the severance compensation and benefits provided pursuant to the Severance Plan if they are entitled to any severance compensation and benefits under any other plan, policy, or other arrangement with the Company or under applicable law, but only to the extent that such other severance compensation and benefits are more favorable to the Eligible Employee than those provided under the Severance Plan, as determined on a per-benefit basis.

For purposes of the Severance Plan, “Cause” means, with respect to an Eligible Employee’s termination of service, the following: (a) in the case where there is no employment agreement, consulting agreement, change in control agreement, or similar agreement in effect between the Company or an affiliate and the Eligible Employee (or where there is such an agreement but it does not define “cause” or words of like import, which shall include but not be limited to “gross misconduct”), termination due to an Eligible Employee’s (1) failure to substantially perform the Eligible Employee’s duties or obey lawful directives that continues after receipt of written notice from the Company and a 10-day opportunity to cure; (2) gross misconduct or gross negligence in the performance of the Eligible Employee’s duties; (3) fraud, embezzlement, theft, or any other act of material dishonesty or misconduct; (4) conviction of, indictment for, or plea of guilty or nolo contendere to, a felony or any crime involving moral turpitude; (5) material breach or violation of any agreement with the Company or its affiliates, any restrictive covenant applicable to the Eligible Employee, or any Company policy (including, without limitation, with respect to harassment); or (6) other conduct, acts, or omissions that, in the good faith judgment of the Company, are likely to materially injure the reputation, business, or a business relationship of the Company or any of its affiliates; or (b) in the case where there is an employment agreement, consulting

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agreement, change in control agreement, or similar agreement in effect between the Company or an affiliate and the Eligible Employee that defines “cause” (or words of like import, which shall include but not be limited to “gross misconduct”), “cause” as defined under such agreement.

Change in Control Severance Plan

Ms. Shamsuddin Jensen and Ms. Lazorchak are, and Mr. Mirisola during the time in which he served as an executive officer during 2023 was, eligible to participate in our executive Change in Control Severance Plan (the “CIC Plan”) as Eligible Employees (as defined in the CIC Plan). If during the CIC Period (as defined in the CIC Plan) we terminate their employment without Cause (as defined below) and other than as a result of death or Disability (as defined in the CIC Plan) then, subject to execution of a general release of claims and certain other conditions set forth in the CIC Plan, we must provide them with (i) continuation of regular payments of base salary for a period of twelve months; (ii) payment of their current year annual bonus at “target” performance levels; and (iii) payment for up to twelve months of COBRA coverage, if applicable.

For purposes of the CIC Plan, “Cause” means with respect to an Eligible Employee’s termination of service, the following: (a) in the case where there is no employment agreement, consulting agreement, change in control agreement, or similar agreement in effect between the Company or an affiliate and the Eligible Employee (or where there is such an agreement but it does not define “cause” or words of like import, which shall include but not be limited to “gross misconduct”), termination due to an Eligible Employee’s (1) failure to substantially perform the Eligible Employee’s duties or obey lawful directives that continues after receipt of written notice from the Company and a 10-day opportunity to cure; (2) gross misconduct or gross negligence in the performance of the Eligible Employee’s duties; (3) fraud, embezzlement, theft, or any other act of material dishonesty or misconduct; (4) conviction of, indictment for, or plea of guilty or nolo contendere to, a felony or any crime involving moral turpitude; (5) material breach or violation of any agreement with the Company or its affiliates, any restrictive covenant applicable to the Eligible Employee, or any Company policy (including, without limitation, with respect to harassment); or (6) other conduct, acts, or omissions that, in the good faith judgment of the Company, are likely to materially injure the reputation, business, or a business relationship of the Company or any of its affiliates; or (b) in the case where there is an employment agreement, consulting agreement, change in control agreement, or similar agreement in effect between the Company or an affiliate and the Eligible Employee that defines “cause” (or words of like import, which shall include but not be limited to “gross misconduct”), “cause” as defined under such agreement.

Pension Benefits

None of our NEOs participate, or have an account balance, in any qualified or non-qualified defined benefit plans sponsored by us.

Nonqualified Deferred Compensation

None of our NEOs participate in any nonqualified deferred compensation plan sponsored by us.

Pay Ratio Disclosure

Pursuant to Item 402(u) of Regulation S-K, presented below is the ratio of annual total compensation of Robert Musslewhite, who served as our CEO for all of fiscal year 2023, to the annual total compensation of our median employee (except Mr. Musslewhite). The ratio presented below is a reasonable estimate calculated in a manner consistent with Item 402(u). The SEC’s rules for identifying the median compensated employee and calculating the pay ratio based on that employee’s annual total compensation allow companies to adopt a variety of methodologies, to apply certain exclusions, and to make reasonable estimates and assumptions that reflect their employee populations and compensation practices. As a result, the pay ratio reported by other companies may

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not be comparable to the pay ratio reported below, as other companies have different employee populations and compensation practices and may utilize different methodologies, exclusions, estimates and assumptions in calculating their own pay ratios.

For fiscal year 2023:

Based on this information, the ratio of the annual total compensation of Mr. Musslewhite to the median of the annual total compensation of all employees was 67 to 1.

We identified our median compensated employee from all full-time and part-time employees who were included as employees on our payroll records as of a determination date of October 31, 2023. We did not include any contractors or other non-employee workers in our employee population. We used base salary as our consistently applied compensation measure. We annualized base salary for any full-time and part-time employees who commenced work during fiscal 2023 to reflect a full year, and non-United States employees’ pay was converted to U.S. dollar equivalents using applicable exchange rates as of the determination date.

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