Merck (NYSE: MRK) EVP nets shares after RSU vest and tax withholding

Rhea-AI Filing Summary

Merck & Co., Inc. executive vice president for Oncology & International, Johannes Jacobus Oosthuizen, reported routine equity compensation activity. He exercised 1,377 Restricted Stock Units (RSUs), converting them into the same number of Merck common shares at a reported value of $110.03 per share. To cover tax obligations, 679 common shares were disposed of through a tax-withholding transaction rather than an open-market sale. Following these transactions, Oosthuizen directly holds about 21,895.389 common shares. Footnotes state that each RSU represents a contingent right to one share of common stock and that the RSUs vest in three equal installments on 4/29/2026, 4/29/2027, and 4/29/2028, highlighting that this event is part of an ongoing vesting schedule.

Insider Trade Summary

1,377 shares exercised/converted

Mixed 3 txns

Insider Oosthuizen Johannes Jacobus

Role EVP, Oncology & Int?l

Type	Security	Shares	Price	Value
Exercise	Restricted Stock Unit	1,377	$0.00	--
Exercise	Common Stock	1,377	$110.03	$152K
Tax Withholding	Common Stock	679	$110.03	$75K

Holdings After Transaction: Restricted Stock Unit — 2,755 shares (Direct, null); Common Stock — 22,574.389 shares (Direct, null)

Footnotes (1)

1. Each restricted stock unit represents a contingent right to receive one share of Merck & Co., Inc. common stock. These restricted stock units vest and are distributed as shares of Merck & Co., Inc. common stock in three equal installments on 4/29/2026, 4/29/2027 and 4/29/2028.

Key Figures

RSUs exercised: 1,377 units Tax-withholding shares: 679 shares Reference share value: $110.03 per share +2 more

5 metrics

RSUs exercised 1,377 units Restricted Stock Units converted into Merck common stock

Tax-withholding shares 679 shares Common shares delivered to satisfy tax obligations

Reference share value $110.03 per share Reported transaction price for common stock entries

Post-transaction holdings 21,895.389 shares Common stock directly held after tax-withholding disposition

Remaining RSUs 2,755 units Restricted Stock Units outstanding after 1,377-unit conversion

Key Terms

Restricted Stock Unit, tax-withholding disposition, derivative exercise/conversion, contingent right, +1 more

5 terms

Restricted Stock Unit financial

"The security title includes "Restricted Stock Unit" with 1,377.0000 shares reported."

A restricted stock unit is a promise from a company to give an employee shares of stock after certain conditions are met, like staying with the company for a set amount of time. It’s like earning a bonus that turns into company stock once you’ve proven your commitment, making it a way to motivate and reward employees.

tax-withholding disposition financial

"The transaction_action field describes a "tax-withholding disposition" for 679.0000 shares."

A tax-withholding disposition is an event or transaction—such as selling or transferring securities, exercising options, or receiving compensation—that triggers a requirement to hold back part of the payment and remit it to tax authorities. It matters to investors because it reduces the cash they receive immediately and can change the timing and amount of taxable income, like a cashier taking a portion of your sale proceeds to pay taxes before you get the rest.

derivative exercise/conversion financial

"Two transactions list the action as "derivative exercise/conversion" with code M."

contingent right financial

"Footnote F1 states each restricted stock unit represents a contingent right to receive one share."

vest and are distributed financial

"Footnote F2 notes the restricted stock units vest and are distributed as shares in three installments."

Form 4 Insider Transactions: What Each Field Means →

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
Estimated average burden
hours per response:			0.5

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^*

Oosthuizen Johannes Jacobus

(Last) (First) (Middle)

MERCK & CO., INC.

126 EAST LINCOLN AVENUE

(Street)

RAHWAY NEW JERSEY 07065

(City) (State) (Zip)

UNITED STATES

(Country)

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

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EVP, Oncology & Int?l

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
04/29/2026

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

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

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

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	04/29/2026		M		1,377	A	$110.03	22,574.389	D
Common Stock	04/29/2026		F		679	D	$110.03	21,895.389	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
Restricted Stock Unit	(1)	04/29/2026		M			1,377	04/29/2026(2)	04/29/2028	Common Stock	1,377	$0	2,755	D

Explanation of Responses:

1. Each restricted stock unit represents a contingent right to receive one share of Merck & Co., Inc. common stock.

2. These restricted stock units vest and are distributed as shares of Merck & Co., Inc. common stock in three equal installments on 4/29/2026, 4/29/2027 and 4/29/2028.

	/s/ Kelly E. W. Grez, as attorney-in-fact for Johannes Oosthuizen	05/01/2026
	** 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.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transactions did Merck (MRK) EVP Johannes Oosthuizen report?

Merck EVP Johannes Oosthuizen exercised 1,377 RSUs into common stock and had 679 shares withheld to cover taxes. These are compensation-related, non‑open‑market transactions, reflecting routine vesting of equity awards rather than discretionary buying or selling of MRK shares.

Did Merck (MRK) EVP Johannes Oosthuizen sell shares in the open market?

The filing shows a tax-withholding disposition of 679 shares, not an open-market sale. Shares were delivered to cover tax obligations arising from RSU vesting, which is a standard mechanism and does not represent a discretionary decision to sell MRK stock in the market.

How many Merck (MRK) shares does Johannes Oosthuizen hold after this Form 4?

After the reported transactions, Johannes Oosthuizen directly holds 21,895.389 shares of Merck common stock. This reflects net holdings following exercise of 1,377 RSUs and a 679‑share tax-withholding event documented in the Form 4 insider trading report.

What Restricted Stock Unit activity was reported for Merck (MRK) EVP Oosthuizen?

Oosthuizen exercised 1,377 Restricted Stock Units, each representing a right to one Merck share. Footnotes state the RSUs vest and are distributed in three equal installments on 4/29/2026, 4/29/2027, and 4/29/2028 as part of an ongoing long‑term incentive program.

Are the Merck (MRK) insider transactions by Johannes Oosthuizen routine compensation events?

Yes. The Form 4 describes an RSU exercise of 1,377 units and a 679‑share tax-withholding disposition. Footnotes explain scheduled vesting dates, indicating these transactions are linked to pre‑granted equity awards rather than new, discretionary buying or selling of MRK shares.