Mr. Chirfi Guindo - 26 Jan 2026 Form 4 Insider Report for Merck & Co., Inc. (MRK)

Role: Chief Marketing Officer
Signature: /s/ Kelly Grez, as attorney-in-fact for Mr. Chirfi Guindo
Issuer symbol: MRK
Transactions as of: 26 Jan 2026
Net transactions value: +$1,059,501
Form type: 4
Filing time: 28 Jan 2026, 16:08:02 UTC
Previous filing: 05 Aug 2025
Next filing: 06 Feb 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Guindo Chirfi	Chief Marketing Officer	MERCK & CO., INC., 126 EAST LINCOLN AVENUE, RAHWAY	/s/ Kelly Grez, as attorney-in-fact for Mr. Chirfi Guindo	28 Jan 2026	0001722753

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	MRK	Common Stock	Award	$1,059,501	+9,865	+11%	$107.40	100,615	26 Jan 2026	Direct	F1, F2
holding	MRK	Common Stock-401(k) Plan						57	26 Jan 2026	By 401(k)	F3

* 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.
F3	Includes shares acquired and dividends earned through January 8, 2026 in the Merck U.S. Savings Plan, a 401(k) plan.