Johannes Jacobus Oosthuizen - 26 Jan 2026 Form 4 Insider Report for Merck & Co., Inc. (MRK)

Role: President, U.S. Market
Signature: /s/ Kelly E. W. Grez, as attorney-in-fact for Johannes Oosthuizen
Issuer symbol: MRK
Transactions as of: 26 Jan 2026
Net transactions value: +$539,792
Form type: 4
Filing time: 28 Jan 2026, 16:12:23 UTC
Previous filing: 01 May 2025
Next filing: 06 Feb 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Oosthuizen Johannes Jacobus	President, U.S. Market	MERCK & CO., INC., 126 EAST LINCOLN AVENUE, RAHWAY	/s/ Kelly E. W. Grez, as attorney-in-fact for Johannes Oosthuizen	28 Jan 2026	0001916310

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	MRK	Common Stock	Award	$539,792	+5,026	+16%	$107.40	36,197	26 Jan 2026	Direct	F1, F2

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Distribution of net after tax shares of common stock on satisfaction of performance criteria for performance share units granted on 3/31/23. Performance shares were paid out at 94 percent of target awards. Includes dividends accrued over the three-year performance period ending December 31, 2025.
F2	Holdings include shares acquired in dividend reinvestment transactions.