Merck (MRK)

=== SEC Form 3 — Statement of Changes in Beneficial Ownership === Document Type: 3 Period of Report: 2026-09-01 --- Issuer --- Name: Merck & Co., Inc. (MRK) CIK: 0000310158 --- Reporting Owner --- Name: Gupta Gaurav K CIK: 0002148939 Role: Officer (EVP, CIDO) --- Holdings --- [Holding #1] Security: Common Stock Ownership: D (Direct) [Holding #2] Security: Restricted Stock Unit Ownership: D (Direct) Footnotes: [F2] Each restricted stock unit represents a contingent right to receive one share of Merck & Co., Inc. common stock. [F1] These restricted stock units vest and are distributed as shares of Merck & Co., Inc. common stock in three equal installments on 8/7/2027, 8/7/2028, and 8/7/2029. --- Footnotes (Complete Index) --- F1: These restricted stock units vest and are distributed as shares of Merck & Co., Inc. common stock in three equal installments on 8/7/2027, 8/7/2028, and 8/7/2029. F2: Each restricted stock unit represents a contingent right to receive one share of Merck & Co., Inc. common stock. --- Signature --- /s/ /s/ Kelly E. Grez, as Attorney-in-Fact for Gaurav Gupta (2026-09-01)