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: Chattopadhyay Sanat (Exe V-P & Pres. MMD)

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2025-04-29	Restricted Stock Unit	$	A	7791	Acquired	2028-04-29	Common Stock (7791)	Direct
2025-04-29	Stock Option (Right to Buy)	$84.71	A	35465	Acquired	2035-04-28	Common Stock (35465)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	7000	Indirect
Common Stock	50622	Indirect
Common Stock	53417	Indirect
Common Stock	74289	Indirect

Footnotes

F1: The reporting person serves as the sole trustee of, and maintains complete investment control over, the Sanat Chattopadhyay February 2024 Grantor Retained Annuity Trust.

F2: The reporting person serves as the sole trustee of, and maintains complete investment control over, the Sanat Chattopadhyay May 2024 Grantor Retained Annuity Trust.

F3: The reporting person serves as the sole trustee of, and maintains complete investment control over, the Sanat Chattopadhyay February 2025 Grantor Retained Annuity Trust.

F4: The reporting person serves as the sole trustee of, and maintains complete investment control over, the Sanat Chattopadhyay April 2025 Grantor Retained Annuity Trust.

F5: Each restricted stock unit represents a contingent right to receive one share of Merck & Co., Inc. common stock.

F6: 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.

F7: The option vests and becomes exercisable in three equal installments on 4/29/2026, 4/29/2027 and 4/29/2028.