Merck & Co., Inc.

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

Business Highlights

Capital Returned & Dividend Increase

Total Shareholder Return(1)

2025 NEOs and Compensation Highlights (Page 48)

Below is a list of our 2025 Named Executive Officers, or “NEOs”, and select compensation highlights from 2025. For additional information on our elements of 2025 compensation, please refer to the Compensation Discussion and Analysis (“CD&A”), beginning on page 43.

Variable Compensation is Critical to Achieve Our Objectives(Page 51)

The Company’s compensation programs are designed to align the interests of our executives with the interests of our shareholders, among other objectives. For this reason, a significant portion of our NEOs’ pay is variable andat-risk, subject to Company performance as measured against financial, operating, and strategic objectives, as well as Relative Total Shareholder Return, or “Relative TSR” or“R-TSR” (as defined in Appendix B). These performance measures continue to demonstrate a strong linkage between pay and performance.

Annual Cash Incentive

The Company Scorecard (described in more detail on page 52) focuses on our most critical business drivers — the Company’s revenue (“Revenue”), non-GAAP pre-tax income(“Pre-Tax Income”), the Company’s research and development goals (“Pipeline”), and the Company’s focus on driving greater access to health for patients around the world and on the engagement and inclusion of our employees (“Sustainability”) — and is used to determine the payout of our annual incentive for most employees, including our NEOs under the Executive Incentive Plan. Our Company Scorecard performance during 2025 resulted in an achievement of 94% of target.

Long-Term Incentive

The Long-Term Incentive (“LTI”) program, consisting of a mix of Performance Share Units (“PSUs”), Restricted Stock Units (“RSUs”) and stock options, provides our NEOs with the opportunity to own Company common stock, directly linking a substantial portion of their compensation to the returns realized by our shareholders.

The 2023 PSU program (described in more detail on page 56) paid out at 94% of target based on achievement of three-year Earnings Per Share (“EPS”) and three-year R-TSR metrics during the performance period (2023-2025), weighted at 50% and 50%, respectively.

Say-On-Pay Advisory Vote (Page 46)

In 2025, shareholders continued their historically strong support for our executive compensation programs with approximately 91% of the votes cast in favor of approving the say-on-pay proposal. Based on this outcome, feedback received from shareholders, and the Compensation and Management Development (“C&MD”) Committee’s ongoing analysis of the program’s ability to support our strategic, financial, and human capital objectives, we did not make significant changes to our executive compensation program in 2025. Consistent with the Company’s strong interest in shareholder engagement and our pay-for-performance approach, the C&MD Committee continues to evaluate our executive compensation program to ensure alignment between the respective interests of our executives and shareholders.

We ask that our shareholders approve, on an advisory basis, the compensation of our NEOs as further described in Proposal 2 on page 42. For additional information, please refer to the CD&A beginning on page 43 of this proxy statement.

Shareholder Engagement and Feedback(Page 24)

The Company communicates regularly with shareholders to better understand their perspectives and has established a shareholder engagement program that is both proactive and cross-functional. Our independent Lead Director, who is also Chair of our Governance Committee, participates in substantive engagements with some of the Company’s largest shareholders. In 2025, discussions with shareholders covered a wide range of topics of interest to shareholders, including the Board’s composition and leadership structure, management and director succession, strategic priorities, capital allocation, executive compensation programs, sustainability reporting and goals, human capital management, and other governance matters. These discussions provided valuable insights into shareholder views, which are varied, and we heard from many shareholders that they greatly appreciated the opportunity to engage with the Company.

We will continue to engage with shareholders on a regular basis to better understand and consider their views, including on our executive compensation programs, our corporate governance practices, and our sustainability approach that is aligned to our Company strategy.

Board Composition and Refreshment(Page 20)

At least annually, the Governance Committee considers the size, structure, and needs of the Board. The Governance Committee reviews possible candidates for the Board and recommends Director nominees to the Board for approval. In addition, as part of the Board’s annual self-evaluation process, Directors provide feedback on Board composition-related matters. Directors also discuss Board composition-related matters from time to time in executive session.

In selecting Director nominees, the Board considers its composition, including the skills, perspectives, areas of expertise, and experience then-represented on the Board. The Board also considers the Company’s current and future global business strategies, opportunities, and challenges. Such considerations have resulted in the election of six new independent Directors since 2020. For more information, see “Board Succession Planning, Criteria for Board Membership, and Director Nomination Process” beginning on page 20.

Our 2026 Director Nominees Snapshot

Our Director nominees possess broad expertise, skills, experience, and perspectives that will facilitate effective oversight of the Company’s current and future global business and strategic initiatives, opportunities, and challenges, and strengthen and support senior management. As illustrated by the following chart, our slate of Director nominees consists of individuals with expertise in fields that align with the Company’s business and long-term strategy.

• See page 21 of this proxy statement under Nominee Skills Matrixfor how these Board skills and qualifications are defined and how they are represented by each Director nominee individually.

Nominees for Director(Page 32)

The following provides summary information about each Director nominee. Each Director stands for election annually. Detailed information about each individual’s background, skillsets, and areas of expertise can be found beginning on page 33.

Committee Chair