Merck (MRK) director updates holdings with stock sale and phantom units

Rhea-AI Filing Summary

Merck & Co., Inc. director Christine E. Seidman reported routine changes in her equity holdings. On 12/31/2025 she disposed of 100 shares of Merck common stock. The filing also shows an acquisition of 77.1898 phantom stock units tied to Merck common stock at a reference price of $105.26 per share, bringing her total phantom stock holdings to 19,025.6686 units held directly.

According to the disclosure, each phantom stock unit is on a 1-for-1 basis with Merck common stock and will be settled 100% in cash after her termination of service, under the company’s deferred compensation plan for directors. Her holdings also include shares previously acquired through dividend reinvestment.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Seidman Christine E

(Last) (First) (Middle)

MERCK & CO., INC.

126 EAST LINCOLN AVENUE

(Street)

RAHWAY NJ 07065

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Merck & Co., Inc. [ MRK ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
12/31/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock								100	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Phantom Stock	(1)	12/31/2025		A		77.1898		(2)	(2)	Common Stock	77.1898	$105.26	19,025.6686(3)	D

Explanation of Responses:

1. 1-for-1

2. Phantom stock units are to be settled 100% in cash upon reporting person's termination of service in accordance with a distribution schedule elected pursuant to the terms of the Plan for Deferred Payment of Directors' Compensation.

3. Holdings include shares acquired in dividend reinvestment transactions.

	/s/ Kelly E. W. Grez as Attorney-in-Fact for Christine E. Seidman	01/05/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transaction did Merck (MRK) report for director Christine E. Seidman?

The filing reports that on 12/31/2025 Christine E. Seidman disposed of 100 shares of Merck common stock and acquired 77.1898 phantom stock units tied to Merck common stock.

How many phantom stock units does the Merck (MRK) director hold after this transaction?

Following the reported transaction, Christine E. Seidman beneficially owns 19,025.6686 phantom stock units directly.

How are the Merck (MRK) phantom stock units for the director settled?

Each phantom stock unit is on a 1-for-1 basis with Merck common stock and is to be settled 100% in cash upon the director’s termination of service under the deferred compensation plan.

What price is referenced for the Merck (MRK) phantom stock units in this filing?

The phantom stock units are shown with a reference price of $105.26 per share of Merck common stock.

Does the Merck (MRK) director’s holding include dividend reinvestment shares?

Yes. The explanation notes that the reported holdings include shares acquired in dividend reinvestment transactions.

Is this Merck (MRK) insider filing made by one or multiple reporting persons?

The document indicates that the Form is filed by one reporting person, covering Christine E. Seidman.