UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the
Securities Exchange Act of 1934 (Amendment No. )

Filed by the Registrant [X]
Filed by a Party other than the Registrant [_]

Check the appropriate box:

Quest Diagnostics Incorporated

Payment of Filing Fee (Check the appropriate box):

The Quest Way

The Quest Way

	Working together to create a healthier world, one life at a time
		We help people make the best decisions to improve health by providing high-quality and affordable diagnostic testing insights and services using our scale and extensive reach •Collaborating with payers, providers and partners to leverage our broad access •Offering the most extensive menu of testing and services •Leveraging our data assets and services to improve population health and enable value-based care •Continuously improving our quality and efficiency by embracing AI, automation and other innovative technologies Who we serve: Patients, Consumers, Physicians, Hospitals, Life Sciences Companies, Employers, Insurers, Public Health Agencies, Communities. And Retailers
		Customer first, Care, Collaboration, Continuous improvement, Curiosity

April 6, 20235, 2024

Dear Fellow Stockholder:

It is my pleasure to invite you to attend Quest Diagnostics’ 20232024 Annual Meeting of Stockholders (the “Annual Meeting”). At the Annual Meeting, stockholders will vote on the following, in addition to any other business as may properly come before the Annual Meeting or any adjournment or postponement thereof:

Attendance at the Annual Meeting is limited to stockholders at the close of business on March 20, 2023,18, 2024, or their duly appointed proxy holder.

We enclose our proxy statement, our Annual Report and a proxy card; distribution of these materials is scheduled to begin on April 6, 2023.5, 2024. Your vote is very important. We urge you to submit your proxy even if you plan to attend the Annual Meeting. Most stockholders may submit a proxy via mail, telephone or the Internet. Instructions on how to submit your proxy are included with your proxy card and these proxy materials. Please submit your proxy promptly.

Thank you for your continued support of Quest Diagnostics.

Sincerely,

Proxy SummaryPROXY SUMMARY

This summary highlights information contained elsewhere in this proxy statement. This summary does not contain all of the information that you should consider, and you should read the entire proxy statement carefully before voting.

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20242025 Annual Meeting of Stockholders

Stockholder proposals submitted pursuant to SEC Rule 14a-8 must be received by Quest Diagnostics Incorporated (“Quest Diagnostics,” the “Company,” “we” or “our”) by December 8, 2023.6, 2024.

Notice of stockholder proposals outside of SEC Rule 14a-8, including nominations (other than proxy access nominations) for the Board of Directors (the “Board”), must be received by the Company no earlier than January 18, 202416, 2025 and no later than February 17, 202415, 2025 and must comply with the requirements set forth in our by-laws. StockholdersIn addition to the requirements set forth in our by-laws, stockholders who intend to solicit proxies for nominations for election to the Board other than the Company’s nominees in reliance on the universal proxy rules (Rule 14a-19 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”)) for nominations for election to the Board must also comply with the additional requirements of Rule 14a-19 and our by-laws.14a-19.

Notice of proxy access director nominations must be received by the Company no earlier than November 8, 20236, 2024 and no later than December 8, 2023.6, 2024.

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Board Nominees

The following table provides summary information about our director nominees.nominees*.

Stephen H. Rusckowski, who served as our CEO and President until November 1, 2022, served as our Chairman through March 31, 2023.

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20222023 Executive Compensation Highlights

Our Board is firmly committed to pay for performance. The table above outlines the main components of our compensation program for executive officers in 2022.The2023. In 2023, the Compensation and Leadership Development Committee, due to diminished demand for COVID-19 testing, implemented a change to no longer measure base business revenue and COVID-19 testing revenue separately, as was done for 2022, and to include COVID-19 revenues in the measure of base business revenue for purposes of performance shares granted in 2023 (except for determining base year revenues).

The objectives of our program are to attract and retain talented executives who have the skills and experience required to help us achieve our strategic objectives, and to align the interests of our executives to those of our stockholders, in each case to advance the long-term interests of our stockholders. The compensation opportunity for our named executive officers is directly tied to corporate performance, including both financial and non-financial results, and individual performance. Due to anticipated volatility in the Company’s COVID-19 testing revenues in 2022, the Committee determined to measure base business revenues and COVID-19 testing revenues separately for purposes of annual incentive awards and designed the performance shares granted in 2022 to include a performance measure focused on COVID-19 revenue. We are making changes in the program, highlighted in the Compensation Discussion and Analysis, for 2023.2024.

The average 20222023 annual incentive payout for our named executive officers on our annual cash incentives under the Senior Management Incentive Plan (“SMIP”) was 131%78% of target. Payout on performance shares for the 3-year performance period ended December 31, 20222023 was 196%186% of target. The following table summarizes annual incentive plan and performance share payouts for the two most recent performance periods for our named executive officers.

Our Compensation Discussion and Analysis, which includes a discussion of our program’s “Best Practices,” begins on page 30.23. The 20222023 compensation of our named executive officers is set forth in tables beginning at page 45.43.

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20222023 Business Performance Highlights

Leveraging our Capabilities and Collaborating

Continuous Improvement

Disciplined Capital Deployment

Management Transition

On November 1, 2022, James E. Davis, previously Executive Vice President, General Diagnostics, was appointed Chief Executive Officer and President of the Company, succeeding Stephen H. Rusckowski, who served as our Chief Executive

	•	We delivered our Invigorate cost excellence program goal of annual savings and productivity improvements of 3% of our costs.
	•	We continue to make progress in using front end automation to enhance specimen processing. In 2023, we completed front end automation upgrades in our Pittsburgh and Dallas laboratories, which is expected to improve quality and productivity.
	•	We expanded our use of AI in 2023 to improve quality, efficiency and workforce experience in several clinical areas, including in microbiology to help identify bacteria as well as in cytogenetics to identify chromosomal abnormalities.
	•	We are leveraging automation and AI to improve productivity and quality across our entire value chain, not just in the laboratory. Other areas of focus include reducing denials and patient concessions, enhancing the digital experience, and selecting and retaining talent.
	•	We created an initiative to deploy generative AI to improve several areas of our business, including software engineering, customer service, claims analysis, scheduling optimization, specimen processing and marketing. We expect to further develop these projects in 2024.
	•	We implemented several initiatives to improve talent retention, including capability-building programs.
	•	We improved retention of our frontline employees by 11%.

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Management Transition

On April 1, 2023, James E. Davis, Chief Executive Officer and President of the Company, was appointed Chairman of the Board, succeeding Stephen H. Rusckowski, who served as our Chief Executive Officer and President for more than a decade. Mr. Davis became Chairman of the Board on April 1, 2023, succeeding Mr. Rusckowski, who serveddecade and as Chairman of our Board through March 2023.

On July 11, 2022, Sam A. Samad joined our Company as an Executive Vice President and, on July 25, 2022, became our Chief Financial Officer. Mr. Samad succeeded Mark Guinan, who in February 2022 announced his intention to retire.

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Contents

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Information About Our Corporate GovernanceINFORMATION ABOUT OUR CORPORATE GOVERNANCE

Proposal No. 1 — Election of Directors

The Board of Directors recommends that you vote FOR each of the nominees described below

Our Board currently has nineten directors. Directors are elected annually for a one-year term concluding on the date of the next annual meeting of stockholders. Each director holds office until his or her successor has been elected and qualified or the director’s earlier resignation, death or removal.

Our Company recently completed a management transition. James E. Davis became Chief Executive Officer In September 2023, Dr. Wilensky informed the Board that she would not seek re-election and Presidentwould be retiring from the Board at the Annual Meeting. The Board would like to thank Dr. Wilensky for her leadership and dedication to Quest Diagnostics’ foundational values during her more than 25 years of service on the Company effective November 1, 2022 and ChairmanBoard. Upon the retirement of Dr. Wilensky, the size of the Board effective April 1, 2023. Mr. Davis succeeded Stephen H. Rusckowski, who served as our Chief Executive Officer and President for more than a decade, and also served as Chairman of our Board until he retired on March 31, 2023. The Board is gratefulwill be reduced to Mr. Rusckowski for his many contributions to our Company.

On July 11, 2022, Sam A. Samad joined our Company as an Executive Vice President and, on July 25, 2022, became our Chief Financial Officer. Mr. Samad succeeded Mark Guinan, who in February 2022 announced his intention to retire.nine directors.

After considering the recommendation of the Governance Committee, the Board nominated the nominees below to serve as directors of Quest Diagnostics. Each nominee other than Dr. Diaz, currently is a director of the Company whose term expires at the Annual Meeting. The Board nominated Dr. Diaz for election for the first time at the Annual Meeting. The Governance Committee evaluated several candidates as potential director nominees. After directors interviewed Dr. Diaz, the Governance Committee unanimously recommended to the Board that Dr. Diaz be nominated to be a director. The biography of each nominee contains information regarding the person’s service as a director of the Company, business experience, other public company director positions and the experience, qualifications, attributes and skills that led the Board to conclude that the person should serve as a director of the Company. The Board believes that each nominee possesses the qualities and experience that nominees should possess in accordance with the Company’s Corporate Governance Guidelines, which set forth the Company’s philosophy regarding Board composition and identify key qualifications and other considerations for the nomination of directors (the relevant portion of the Company’s Corporate Governance Guidelines is set forth below under the heading “Board Nomination Process” beginning on page 9). Each nominee has consented to serve if elected.

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THE BOARD OF DIRECTORS RECOMMENDS THAT YOU VOTE FOR EACH NOMINEE. PROXIES SOLICITED BY THE BOARD THAT HAVE BEEN SIGNED AND RETURNED WILL BE VOTED FOR EACH NOMINEE UNLESS OTHERWISE INSTRUCTED.

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Governance Practices

The Board believes that good corporate governance, designed to protect and enhance stockholder value, is important. The Company has strong corporate governance structures, processes, policies and practices. We engage with our stockholders and listen to their concerns. Our Board benefits from knowledgeable independent directors.

The Board has adopted Corporate Governance Guidelines to enhance its own effectiveness and to demonstrate its commitment to strong corporate governance for the Company. The Board reviews these Guidelines no less frequently than annually, including in response to changing regulatory requirements, evolving practices and the concerns of our stockholders. The Company also has adopted a Code of Ethics applicable to all directors, officers and employees. The Corporate Governance Guidelines and Code of Ethics are published on our website at www.QuestDiagnostics.com. The information on or accessible through our website is not incorporated by reference in this Proxy Statement.

		Commitment to board refreshment – eightnine new directors since 2014, including with significant CEO experience
		Eight of nine directorsdirector nominees are independent (our CEO and President is our only non-independent director)
		Five of nine directorsdirector nominees are women or ethnically diverse
		Cybersecurity Committee of the Board since 2019
		Annual election of entire board
		Majority voting standard for director elections
		Annual assessment of Board and Committee structure and performance
		Lead Independent Director with clearly defined role and robust responsibilities
		Regular executive sessions for independent directors only, presided over by Lead Independent Director
		Independent directors receive a majority of their annual compensation in equity to further align their interests with our stockholders’ interests
		Committee assignments are regularly reviewed and selected with a view to continuity and diversity
		Annual reviews of succession planning and development of management personnel

		Proxy access right for stockholders
		Right to request that the Company call a special meeting of stockholders
		Right to act by written consent
		No “poison pill” stockholders’ rights plan
		No supermajority voting requirements
		Annual say-on-pay vote
		Active stockholder engagement

		Committees report on their activities to the Board at each Board meeting
		Director education programs conducted by third parties provided for our directors
		Public disclosure of corporate political contributions policy and information regarding corporate political expenditures
		Board materials provided to directors in advance of meetings to allow preparation for discussion of items
		Board portal enhances the Board’s efficiency, access to information, security and communication
		Independent directors have unlimited access to officers and employees of the Company
		Board and committees have access to and the authority to retain independent legal, financial or other advisors

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Corporate Responsibility

The Company and the Board take seriously the responsibility of corporate stewardship, which includes creating a healthier world and building value for all stakeholders. The Company has a deep commitment to its patients, employees, communities and the environment. The Company aims to do business in an environmentally sustainable, socially responsible manner and make a difference in the communities in which it operates. We maintain a Corporate Responsibility webpage, www.QuestDiagnostics.com/our-company/corporate-responsibility, that provides information about our corporate responsibility program, including our focus on environmental, social and governance (“ESG”) issues. The information on or accessible through our website is not incorporated by reference in this Proxy Statement.

	Approximately 72% of employees identify as women and approximately 50% of U.S. employees identify as people of color
		Ten Employee Business Networks (including African-American Business Leaders, DiverseAbilities, Hispanic/Latino, Pan Asian Leaders and Women in Leadership) that work closely with our talent acquisition team to bring in diverse talent and support them through targeted mentoring and training programs
		Initiatives to conserve resources and minimize the negative impact of our operations and facilities on the environment through pollution prevention, energy efficiency, fleet conservation, and strategic sourcing
		Environment, Health and Safety program reduces risk of employee injury
		Patient Assistance Program tailors solutions for uninsured or underinsured patients based on individual circumstances
		“Action with Integrity” Code of Ethics reflects the Company’s commitment to operate as a trustworthy, transparent and ethical organization
		Collaborations with nonprofit organizations improve access to care through donated services, charitable giving, and thought leadership
		Quest for Health Equity®, a $100 million-plus initiative to help reduce health disparities in underserved American communities
		Employee volunteer program Quest Community Action Network, with chapters across the country, has raised millions of dollars for worthwhile causes
		Support employee service with the Company’s Matching Gifts programs, which provide funds to hundreds of nonprofit organizations that share the Company’s commitment to empowering better health and fostering inclusion
		Named as one of Fortune’s World’s Most Admired Companies in 20232024 for the ninthtenth consecutive year
		Named a Best Place to Work for LGBTQ Equality, based on the Human Rights Campaign Foundation Corporate Equality Index 2022
		Ranked as one of Forbes America’s Best Large Employers in 2023
		Named one of America’s Greatest Workspaces for Diversity in 20232024 by Newsweek

Director Independence

The Board assesses the independence of each director annually, and of each director nominee, in accordance with the Company’s Corporate Governance Guidelines and New York Stock Exchange (“NYSE”) listing standards. The independence guidelines in the Corporate Governance Guidelines are consistent with the independence

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requirements in the NYSE listing standards and include guidelines as to categories of relationships that are considered not material for purposes of director independence.

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All members of the Audit and Finance Committee, the Governance Committee, and the Compensation and Leadership Development Committee must be independent under NYSE listing standards and the Company’s Corporate Governance Guidelines. Pursuant to the charters of the Audit and Finance Committee and the Compensation and Leadership Development Committee, respectively, members of these committees also must satisfy separate independence standards based on requirements of the Securities and Exchange Commission (“SEC”) and NYSE, respectively.

The Board has determined that a substantial majority (eight of nine) of our directors, as well as our new director nominee, Dr. Diaz,nominees are independent. Each member, including the chair, of each of the Audit and Finance Committee, the Compensation and Leadership Development Committee, the Governance Committee, the Cybersecurity Committee and the Quality and Compliance Committee qualifies as independent, including under the committee-specific independence requirements discussed above. In making its determinations as to the independence of the directors, the Board reviewed relationships between the Company and each of them. The Board considered the ordinary course commercial relationships in the last three years between the Company and the entity of which Mr. Lassiter is an executive officer and determined that these relationships did not exceed the thresholds under the NYSE listing standards and did not otherwise impair Mr. Lassiter’s independence.

The Board has determined the following directors and nominee to be independent:

	Luis A. Diaz, Jr., M.D.			Timothy L. Main
Tracey C. Doi			Denise M. Morrison
	Tracey C. DoiVicky B. Gregg			Gary M. Pfeiffer
	Vicky B. Gregg		Timothy M. Ring
	Wright L. Lassiter III		Gail R. Wilensky, Ph.D.
	Timothy L. Main		Timothy M. Ring

Mr. Davis, who is the Company’s Chairman, Chief Executive Officer and President, is not independent.

Stockholder Access and Outreach

Stockholders and any other person may communicate with the Board by sending comments to our Lead Independent Director through the web form available at www.questdiagnostics.com/contact-us/lead-independent-director, or by writing to the full Board or any individual director or any group or committee of directors, c/o Corporate Secretary, 500 Plaza Drive, Secaucus, New Jersey 07094. Communications received are reviewed by the Corporate Secretary and handled in accordance with protocols approved by the Governance Committee and forwarded to the intended directors as appropriate.

We have a program of ongoing dialogue with our investors and regularly reach out to large stockholders to listen to their concerns and to inform them about the Company. Our Board receives reports regarding these discussions. During the past year, we reached out to stockholders holding approximately two-thirdsthree-quarters of the Company’s outstanding common stock, and held discussions with those that accepted our invitation and others that reached out to us. These discussions addressed topics such as corporate governance, executive pay, company strategy and the Company’s approach to other ESG issues. During these discussions during the past year, investors generally shared positive feedback regarding the Company’s structuring of and overall approach to corporate governance and executive pay, as well as the other topics discussed. Further, our Corporate Governance Guidelines publicly affirm the Board’s long-standing approach of being available for discussions with stockholders in appropriate circumstances.

The Audit and Finance Committee maintains a procedure whereby complaints and concerns with respect to accounting, internal controls and audit matters may be submitted to the Audit and Finance Committee. All communications received by a director relating to the Company’s accounting, internal controls or audit matters are immediately forwarded to the Chair of the Audit and Finance Committee and are investigated and responded to in accordance with the procedures established by the Audit and Finance Committee. In addition, the Company has established a hotline (known as CHEQline) pursuant to which employees can anonymously report accounting, internal controls, and financial irregularities (as well as compliance concerns on other laws, and other issues).

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Our Corporate Governance Guidelines provide that directors are encouraged and expected to attend the Annual Meeting. All our directors then in office attended the 20222023 annual stockholders meeting.

Board Nomination Process

The Governance Committee is responsible for reviewing with the Board, on an annual basis, the composition of the Board as a whole and whether the Company is being well served by the directors, taking into account each director’s independence, skills, experience, tenure, availability for service to the Company and other factors the Governance Committee deems appropriate. The Governance Committee is responsible for recommending director nominees to the

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Board, including re-nomination of persons who are already directors. The Governance Committee does not set specific, minimum qualifications that nominees must meet in order for the Governance Committee to recommend them to the Board, but rather believes that each nominee should be evaluated based on his or her own merits, taking into account the Company’s needs, Board succession planning considerations, and the overall composition of the Board, which includes an analysis of current directors’ skills and experience. Recommendations are made by the Governance Committee in accordance with the Company’s Corporate Governance Guidelines, which set forth the Company’s philosophy regarding Board composition and identify key qualifications and other considerations. The Governance Committee believes that the Board should be comprised of individuals whose backgrounds and experience complement those of other Board members, and considers whether a prospective nominee promotes a diversity of talent, skill, tenure, expertise, background, perspective and experience, as well as diversity with respect to age, gender identity, race, ethnicity, place of residence, sexual orientation and specialized experience. The Governance Committee does not assign specific weights to particular criteria and nominees are not required to possess any particular attribute.

The key qualifications and other considerations set forth in the Company’s Corporate Governance Guidelines are set forth below.

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In recruiting and selecting a Board candidate, as a supplement to the key qualifications and other considerations for director candidates outlined in the Corporate Governance Guidelines, the Governance Committee considers other important skills and professional experiences to determine whether a candidate has skills and experience well-suited for the expected needs of the Board, including whether the skills and experience complement those of the other Board members or nominees. The table below includes, for each director nominee, an illustrative, non-exhaustive listing of supplemental skills and experiences that the Board considered most relevant when nominating that nominee. Although a check mark indicates that the Board relied upon the specific skill or experience in making its decision, the absence of a check mark does not mean the nominee does not possess the specific skill or experience. The biographies beginning on page 2 provide more information on each nominee’s skills and experience. The table also provides self-identified demographic and tenure information regarding each nominee.

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Davis

Diaz

Doi

Gregg

Lassiter

Main

Morrison

Pfeiffer

Ring

Wilensky

Davis

Diaz

Doi

Gregg

Lassiter

Main

Morrison

Pfeiffer

Ring

Skills and Experience

Accounting/Finance

✓

✓

Advisory

✓

Capital Markets

✓

✓

Consumer Focus

✓

✓

Corporate Governance

✓

✓

Cybersecurity/Technology

Executive Management

✓

✓

Government

✓

Healthcare

✓

✓

✓

International

✓

✓

✓

Operations

✓

✓

✓

✓

Medical/Science

✓

✓

Strategic Planning

✓

✓

Demographics

Race/Ethnicity

African American

✓

Asian/Pacific Islander

✓

Hispanic/Latino

✓

White/Caucasian

✓

✓

✓

Gender

Male

✓

✓

✓

Female

✓

✓

✓

✓

Board Tenure

Years

<1

0

1

9

3

9

4

19

12

26

1

2

10

4

10

5

20

13

The Governance Committee regularly reviews the Board’s composition to ensure that we continue to have the right mix of skills, diversity, background and tenure reflected on the Board. Our Board’s membership represents a balanced approach to director tenure, allowing the Board to benefit from the experience of longer-serving directors

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as well as the fresh perspectives of newer directors. The composition of the director nominee group (assuming Dr. Diaz’s election at the Annual Meeting) with respect to tenure and ethnic and gender diversity are shown below:

The Board is committed to fostering diversity of the Board. In addition to valuing diversity of talent, skill, tenure, expertise and experience, the Board seeks to include directors with diverse backgrounds, including with respect to race, ethnicity, age, gender identity and sexual orientation, in order to ensure that diverse perspectives are included on the Board. When conducting searches for new directors, it is the Board’s policy to actively and routinely seek a diverse candidate pool, including women and ethnically diverse candidates. The Board assesses the effectiveness of this process each time a new director is nominated to join the Board.

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Governance Committee identifies, assesses, and ranks candidates   •  Seeks input from Board members •  Considers recommendations submitted by other sources, including stockholders •  Considers retaining third-party search firms to assist in identifying and evaluating candidates for nomination

Interview of candidates by
•  Chairman and Chief Executive Officer •  Lead Independent Director	•  Other Board members •  Members of senior management may also interview candidates

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The Governance Committee considers suggestions from many sources, including stockholders, regarding possible candidates for director. Stockholders may recommend candidates for consideration as director by sending comments to our Lead Independent Director through the web form available at www.questdiagnostics.com/contact-us/lead-independent-director or writing to the full Board or any independent Board member, c/o Corporate Secretary, 500 Plaza Drive, Secaucus, New Jersey 07094. The recommendation should contain the proposed nominee’s name, biographical information and relationship to the stockholder. The Governance Committee evaluates stockholder recommendations for director candidates in the same manner as other director candidate recommendations. Stockholders may also nominate director candidates. See “Frequently Asked Questions” beginning on page 7769 for information regarding the process and deadline for stockholders to submit director nominations for the 20242025 annual meeting of stockholders.

Board Committees

During 2022,2023, the Board held nineeight meetings. In order to fulfil its responsibilities, the Board has delegated certain authority and responsibilities to its six standing committees. The Board’s structure and operations reflect its alignment on ESG issues. The Board holds primary responsibility for oversight of human capital management issues, as reflected in the Corporate Governance Guidelines. The Board expects to continue to monitor developments related to ESG issues and whether its allocation of responsibilities remains appropriate. RecentlyIn 2023, the Board renamed the Compensation Committee the Compensation and Leadership Development Committee and revised the committee’s charter to include leadership development for senior management other than the Chief Executive Officer. As discussed under the heading “Board, Committee and CEO Evaluation Process” beginning on page 17, each committee reviews its own performance.

In 2022,2023, each nominee attended at least 75% of the meetings of the Board and the Board committees on which he or she served held during the period such nominee was in office. Any director may attend meetings of any committee of which the director is not a member.

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For each year, a schedule of Board meetings is established before the year begins. Committee meetings are generally scheduled for shortly before, or the day of, meetings of the full Board, except that meetings of the Executive Committee are scheduled only when needed. The Board and each committee also hold such additional meetings as the Board or committee, respectively, determines necessary or appropriate. Set forth below is a brief description of each standing committee and its function, its membership and the number of meetings it held during 2022. The Board will identify committee appointments for Dr. Diaz following his election to the Board.2023. Additional information about the committees can be found in their charters, which are available on our website at www.QuestDiagnostics.com.

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Board Leadership Structure

At Quest Diagnostics, we recognize the importance of good corporate governance and value the leadership and input of the independent members of our Board. The Board believes that its leadership structure should be determined by what is in the best interest of the Company. The Board does not have a policy that requires the combination or separation of the Chair and Chief Executive Officer roles. The Board has revised its leadership structure from time to time and retains the flexibility to revise its leadership structure if, in the exercise of its fiduciary duties, the Board believes that such revision is appropriate. Currently, the roles of Board Chair and Chief Executive Officer are combined with James E. Davis. The Board believes that Mr. Davis’ long tenure with the Company in multiple roles and his extensive industry experience make him well-suited to facilitate the Board’s oversight of our operations, strategy and risk. In accordance with the Company’s Corporate Governance Guidelines, where the Board Chair is not an independent director, the independent directors designate a Lead Independent Director, who has a robust set of responsibilities set forth in our Corporate Governance Guidelines and described below under the heading “Principal Responsibilities of the Lead Independent Director,” and who assists with the administration and organization of the Board and facilitates the effective performance of its duties, including the activities of the independent directors. The independent directors have selected Timothy M. Ring to serve as Lead Independent Director.

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We also have other mechanisms in place to promote the appropriate level of independence and oversight in Board decisions. See “Corporate Governance Highlights” on page 7.6.

Board Oversight of Company Culture and Human Capital

The Board is committed to fostering a strong culture of compliance and ethical conduct and has structured its committees and their activities to support its commitment. The Board supports management’s promotion of a corporate culture of integrity, ethical behavior and compliance with laws and regulations and efforts to ensure that the Company’s culture and its strategy are aligned. The Board expects all directors, as well as officers and employees, to conduct themselves in a manner consistent with our Code of Ethics and our values. The Board believes that a strong culture of integrity, ethics and compliance is fundamental to the conduct of the Company’s business, and is necessary for effective risk management, maintaining investor trust, and successful corporate governance.

We have long strived to create an inspiring workplace, and this has driven our approach to human capital management. Effectively managing our human capital resources is a priority with key components that include culture, safety and well-being programs, employee engagement, and development and succession planning. Our Board actively engages in oversight of our human capital management, including by receiving management reports on key areas, strategies and initiatives. Additional information about our human capital management strategies and initiatives is available in our 20222023 Annual Report on Form 10-K and our 20212022 Corporate Responsibility Report, each of which is available on our website at www.QuestDiagnostics.com.www.QuestDiagnostics.com.

Board, Committee and CEO Evaluation Process

The Board annually conducts a self-evaluation of its performance and effectiveness. The charter of each standing committee of the Board, discussed under the heading “Board Committees” beginning on page 12, calls for the committee to conduct an annual self-evaluation of its performance, and report to the Board the results of the self-evaluation. The Governance Committee is tasked with establishing criteria and processes for and overseeing the annual self-evaluation of the Board and the committees. Each year, the Governance Committee discusses the appropriate approach for that year’s Board and committee evaluations.

Prior to the meeting at which each annual self-evaluation occurs, each member of the Board and the committees receives a discussion outline, which encourages the directors to consider the Board’s or committee’s structure, processes, overall effectiveness, and improvement since the previous year’s assessment. In addition, our General Counsel discusses individually with each director, and with members of our senior management, the self-evaluation items and compiles feedback received for discussion with the Lead Independent Director and the full Board. At the meeting, the Lead Independent Director or the committee chair, as applicable, leads a discussion guided by the outline provided, and the Board or committee, as applicable, identifies action items as well as items for further review.

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Periodically (including in 2023), the Board engages an independent consultant to assist with the evaluation, including evaluating individual director performance. When the Board evaluates individual director performance, input from other directors and senior management is considered, in a process that protects anonymity to ensure honest feedback. In these situations, the independent consultant and the Lead Independent Director together review the results of the individual director evaluations with the individual directors. The Lead Independent Director reviews the remaining items with the Board and assists the Board in identifying action items as well as items for further review.

In addition, the Compensation and Leadership Development Committee, pursuant to its charter, conducts an annual review of the Chief Executive Officer’s performance, receives input on the review from the Board, and reports the results of its review to the Board. Pursuant to our Corporate Governance Guidelines, the Board, led by the Lead Independent Director, reviews the Compensation and Leadership Development Committee’s report in order to ensure that the Chief Executive Officer is providing the necessary leadership for the Company in light of the Company’s current and longer-term goals. The Board then provides feedback to the Chief Executive Officer regarding his performance.

Board Role in Risk Oversight

The Board and its committees play an active role in overseeing the Company’s key risks. As highlighted in the table below, the Board has delegated primary responsibility for overseeing our enterprise risk management program to the Audit and Finance Committee, and has assigned oversight of specific risks to the Board committee with the appropriate subject matter responsibility, as set forth in the committee charters. The Board has also considered its role in risk oversight in determining the current Board leadership structure. The Company’s management is responsible for risk management, which it does through a committee of senior managers that leads the Company’s enterprise risk management program. The program includes a formal continuous process that identifies, assesses, mitigates and manages the risks from both internal and external conditions that could significantly impact the Company and influence its business strategy and performance, including ESG issues.ESG-related matters. The program is designed to focus on the Company’s key risk types, which are: operational; financial; legal and compliance; and strategic. The Company’s key risks currently include without limitation: medical quality, cybersecurityAs part of our program, the Board and business continuity.its committees receive updates and training from internal and external experts on topics that are relevant to overall risk management. The Company’s enterprise risk management program, including cybersecurity risk management and strategy, is discussed in the Company’s Annual Report on Form 10-K.

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Related Person Transactions

The Company has a written policy pursuant to which it evaluates proposed transactions involving a related person and the Company in which the amount involved exceeds $120,000. A related person is any director or executive officer of the Company, any immediate family member of a director or executive officer, or any person who owns 5% or more of the Company’s outstanding common stock. The office of the General Counsel is primarily responsible for the administration of the policy and for determining, based on the facts and circumstances, whether the Company or a related person has a direct or indirect material interest in the transaction. Certain transactions are defined not to be related person transactions under the policy.

The Governance Committee reviews any proposed transaction in which a related person has a direct or indirect material interest, except for any compensation arrangements involving an immediate family member of a director or an executive officer. In the event that the General Counsel becomes aware of a related person transaction not approved in advance, the General Counsel will arrange for the related person transaction to be reviewed at the next regularly scheduled meeting of the Governance Committee. Any member of the Governance Committee who is a related person with respect to a transaction under review may not participate in any review, consideration or approval of the transaction.

In considering any related person transaction, the Governance Committee determines whether the transaction is fair to the Company. In considering a proposed transaction involving a director or the immediate family member of a director, the Governance Committee also assesses whether the proposed transaction could reasonably be expected to impact the independence of the director under the Company’s Corporate Governance Guidelines, the NYSE listing standards or other applicable rules.

Compensation arrangements involving an immediate family member of an executive officer are reviewed and approved by the Chief Executive Officer and the Senior Vice President, Chief Human Resources Officer, unless such person is an immediate family member of the Chief Executive Officer, in which case the compensation arrangement is approved by the Compensation and Leadership Development Committee. Compensation arrangements involving an immediate family member of a director are reviewed and approved by the Compensation and Leadership Development Committee.

During 2022,2023, there were no related person transactions meeting the requirements for disclosure in this proxy statement.

Policies Regarding Hedging and Pledging our Common Stock; Window Periods

Our directors and executive officers are prohibited from pledging the Company’s common stock to secure a loan and from holding such stock in a margin account. Our directors and employees, including executive officers, are prohibited from entering into transactions or purchasing financial instruments that are expected to hedge or offset, or designed to hedge or offset, a decline in our common stock price, including, but not limited to, the use of financial derivatives (including, for example, prepaid forward contracts, equity swaps, collars, puts and calls or exchange funds). Our directors and employees, including executive officers, also are prohibited from entering into transactions (including, for example, short sales) that establish downside price protection for our common stock. In addition, our directors and executive officers, as well as certain other employees, generally may purchase or sell

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Company securities only during permitted window periods (generally beginning on the business day following the issuance of our quarterly earnings releases and continuing until the end of the second month of the fiscal quarter).

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Director Compensation Program for 20222023.. The following table sets forth the 20222023 compensation of our non-employee directors then in office. No changes to our director compensation program were made in 2022.2023. Mr. Rusckowski and Mr. Davis, each of whom served as an employee director during 2022,2023, received no additional compensation in 20222023 for serving as director. None of our non-employee directors receives any consulting or other non-director fees from the Company.

Annual Cash Retainer Fees.. During 2022,2023, our non-employee directors received an annual cash retainer fee. Directors serving on Board committees also received additional retainers for such service, and directors who served as Lead Independent Director and committee chairs each received an additional fee for such service. All such cash retainer fees were paid at annual rates as set forth in the table below.

Equity AwardsAwards.. Each non-employee director participates in the Company’s Long-Term Incentive Plan for Non-Employee Directors (the “Director Plan”). The Director Plan currently authorizes the grant to each non-employee director, on the date of the annual stockholders meeting, of stock options and stock awards covering shares of common stock having an aggregate value on the date of grant not exceeding $500,000. If a person is appointed or

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elected as a director other than on the date of the annual stockholders meeting, the Board may grant to such director a prorated equity award, in such proportions as the Board may determine. Annual option grants become exercisable, and annual RSUs generally vest and convert to shares of our common stock, in three equal annual installments, beginning on the first anniversary of the grant date, regardless of whether the non-employee director remains a director. The Director Plan also permits the

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Board to grant to any non-employee director an equity award for any special service as a director (e.ge.g.., service on a special purpose committee). Special service equity awards shall not exceed the grant date value of the annual equity award granted to each non-employee director at the most recent annual meeting of stockholders. The exercise price of all stock options issued under the Director Plan is the fair market value of our common stock on the grant date. Options, once vested, will be exercisable through the tenth anniversary of the date of grant even if the director’s service on the Board terminates.

For 2022,2023, the Board fixed the value of the annual equity award to non-employee directors at $180,000 and determined that the award would be delivered entirely in the form of RSUs. The 20222023 award was granted effective May 18, 2022,17, 2023, with each non-employee director then in service receiving an award of 1,2921,369 RSUs.

A non-employee director may elect to receive annual retainer fees in stock awards in lieu of cash. The number of shares issued in lieu of cash for the retainer fees is based on the fair market value of the stock on the date that the cash payment would otherwise be made.

Opportunity to Defer CompensationCompensation.. Under the Company’s Deferred Compensation Plan for Non-Employee Directors, each non-employee director may elect to defer, until a date specified by the director or until the director’s termination of service as a director, the director’s cash compensation or any stock grants awarded pursuant to the Director Plan. If a director specifies a deferral date that is prior to the director’s termination of service, the payout will occur or commence, as applicable, upon termination of service as a director. Cash amounts deferred may be indexed to (i) a cash account under which amounts deferred earn interest, compounded quarterly, at a rate in effect on the first date of each calendar quarter or (ii) the Company’s common stock.

Changes in Director Compensation Program for 20232024.. No changes were made in the compensation program for directors for 2023.2024.

We encourage our directors, officers, and employees to own our common stock, which aligns their interests with the interests of our stockholders. The Company maintains stock ownership and retention guidelines for its directors and executive officers. The guidelines call for our directors to beneficially own not less than 6,000 shares of our common stock. Until a director satisfies the minimum shareholding requirement, directors are required to maintain 75% of net shares received from vesting of RSUs and from the exercise of options. For purposes of determining whether a director has met the minimum shareholding requirements, we count shares subject to unvested RSUs, but not shares subject to stock options. The guidelines for our executive officers are discussed in “Compensation Discussion and Analysis” beginning on page 24.23.

The following tables show the number of shares of the Company’s common stock beneficially owned by (1) each person who is known to the Company to own beneficially more than 5% of the Company’s common stock, (2) each director of the Company and each nominee, (3) each named executive officer, currently employed,and (4) each named executive officer no longer employed, and (5) all directors, nominees and named executive officers currently employed as a group. Information in the table regarding the Company’s directors, nominees and executive officers is provided as of March 8, 2023.2024.

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Information Regarding Executive CompensationINFORMATION REGARDING EXECUTIVE COMPENSATION

Proposal No. 2 — Advisory Resolution to Approve Executive Officer Compensation

Section 14A of the Exchange Act entitles stockholders to vote to approve or not approve, on an advisory (non-binding) basis, our executive officer compensation as disclosed in the Compensation Discussion and Analysis and accompanying compensation tables and narrative. We are asking stockholders to approve the following resolution:

RESOLVED, that the compensation paid to the Company’s named executive officers, as disclosed in this proxy statement pursuant to the compensation disclosure rules of the SEC, including the Compensation Discussion and Analysis, compensation tables and related narrative disclosure, is hereby APPROVED.

Pay for Performance. As discussed in “Compensation Discussion and Analysis” below, our executive compensation program is designed to pay for performance, to align the interests of our executive officers with the interests of our stockholders and to support the Company’s long- and short-term business goals. Our program reflects many “best practices,” and our executive compensation structure and levels in 20222023 clearly demonstrate our commitment to aligning pay and performance.

Advisory Vote. This vote is advisory. We conduct an advisory vote to approve executive officer compensation annually; the next stockholder advisory vote to approve executive compensation will take place after consideringat the resultsCompany’s 2025 annual meeting of the stockholder vote on Proposal No. 3.stockholders. This vote is not intended to address any specific item of compensation, but rather the overall compensation of our named executive officers and the executive compensation policies and practices described in this proxy statement. The Board and the Compensation and Leadership Development Committee value the opinions of the Company’s stockholders and will take into account the outcome of the vote, in conjunction with such other factors as the Board and the Compensation and Leadership Development Committee consider appropriate, in connection with the Company’s executive compensation program.

THE BOARD OF DIRECTORS RECOMMENDS THAT YOU VOTE FOR THIS PROPOSAL. PROXIES SOLICITED BY THE BOARD THAT HAVE BEEN SIGNED AND RETURNED WILL BE VOTED FOR THIS PROPOSAL UNLESS OTHERWISE INSTRUCTED.

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Proposal No. 3 — Advisory Vote to Recommend the Frequency of the Executive Officer Compensation Advisory Vote

Pursuant to Section 14A of the Exchange Act, we are required, at least once every six years, to hold a stockholder advisory vote to recommend the frequency with which we conduct a stockholder advisory vote on executive compensation. This proposal gives you the opportunity to vote, on an advisory (non-binding) basis, on how often the Company will conduct a stockholder advisory vote on executive officer compensation. You may vote on whether you prefer that the Company conduct such an advisory vote every one, two, or three years. You may also vote to abstain.

Annual Vote Recommended. Our Board unanimously recommends that stockholders vote in favor of conducting the advisory vote on executive compensation required by Section 14A of the Exchange Act annually. We held our last vote to recommend the frequency of the stockholder advisory vote on executive compensation at our 2017 annual stockholders meeting. In 2017, a significant majority of our stockholders voted in favor of conducting the advisory vote on executive compensation annually, and our experience in the past six years has shown that conducting the vote every year is currently the most appropriate option. An annual vote allows stockholders to provide us with direct and immediate feedback regarding our executive compensation program. It also fosters stockholder communications and is consistent with our practice of engaging with our stockholders, and obtaining their input, on our executive compensation program. The Board is open to receiving from our stockholders at any time specific concerns regarding the Company’s executive compensation program.

Advisory Vote. This vote is advisory. The Board and the Compensation and Leadership Development Committee value the opinions of the Company’s stockholders and will take into account the outcome of the vote, in conjunction with such other factors as the Board and the Compensation and Leadership Development Committee consider appropriate, when determining the frequency of future advisory votes on executive compensation.

THE BOARD RECOMMENDS A VOTE TO CONDUCT THE ADVISORY VOTE ON EXECUTIVE COMPENSATION EVERY “ONE YEAR.” PROXIES SOLICITED BY THE BOARD WILL BE VOTED “ONE YEAR” WITH RESPECT TO THIS PROPOSAL UNLESS OTHERWISE INSTRUCTED.

Compensation Discussion and Analysis

Executive Summary

Introduction

The Compensation and Leadership Development Committee (the “Committee”) determined 20222023 compensation for the Company’s named executive officers after considering, among other things, the Company’s performance, (including our continued response to the COVID-19 pandemic), the competitive market for executive talent, and the current environment in the healthcare industry, including in diagnostic information services. We believe that our executive compensation structure, compensation opportunity levels, and pay outcomes in 20222023 reflect our firm commitment to the core principles of our executive compensation philosophy, which is designed to motivate leaders, and to align pay with performance, the Company’s financial results and the interests of stockholders and stakeholders. Our named executive officers are listed below.

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2023 Company Performance

In 2023, we continued to make progress by executing on our business strategy and delivering on our earnings commitments to stockholders and stakeholders. The Company improved on financial and operating metrics and met several key financial targets, despite the nation’s diminishing demand for COVID-19 testing.

2022 Company Performance