X0306 4 2022-02-24 0000310158 Merck & Co., Inc. MRK 0001670690 Chattopadhyay Sanat MERCK & CO., INC. 2000 GALLOPING HILL ROAD KENILWORTH NJ 07033 1 Exe V-P & Pres. MMD Common Stock 2022-02-24 4 A 0 19836 73.51 A 112981.357 D Distribution of net after tax shares of common stock on satisfaction of performance criteria for performance share units granted on 3/29/19. Performance shares were paid out at 140 percent of target awards. Includes dividends accrued over the three-year performance period ending December 31, 2021. Holdings include shares acquired in dividend reinvestment transactions. /s/ Kelly E. W. Grez as Attorney-in-Fact for Sanat Chattopadhyay 2022-02-28