Merck & Co., Inc. — Director's Dealing 2025

May 2, 2025

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Merck & Co., Inc. (MRK)
CIK: 0000310158
Period of Report: 2025-04-29

Reporting Person: Zachary Jennifer (EVP, General Counsel)

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2025-04-29	Restricted Stock Unit	$	A	8854	Acquired	2028-04-29	Common Stock (8854)	Direct
2025-04-29	Stock Option (Right to Buy)	$84.71	A	40301	Acquired	2035-04-28	Common Stock (40301)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	55831.181	Direct

Footnotes

F1: Holdings include shares acquired in dividend reinvestment transactions.

F2: Each restricted stock unit represents a contingent right to receive one share of Merck & Co., Inc. common stock.

F3: These restricted stock units vest and are distributed as shares of Merck & Co., Inc. common stock in three equal installments on 4/29/2026, 4/29/2027 and 4/29/2028.

F4: The option vests and becomes exercisable in three equal installments on 4/29/2026, 4/29/2027 and 4/29/2028.