Merck & Co., Inc. — Director's Dealing 2023

May 5, 2023

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Merck & Co., Inc. (MRK)
CIK: 0000310158
Period of Report: 2023-05-03

Reporting Person: MIZELL STEVEN (EVP, Chief HR Officer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2023-05-03	Common Stock	M	13000	$77.62	Acquired	46085.145	Direct
2023-05-03	Common Stock	M	15000	$75.36	Acquired	61085.145	Direct
2023-05-03	Common Stock	M	12000	$73.73	Acquired	73085.145	Direct
2023-05-03	Common Stock	S	13000	$119.0086	Disposed	60085.145	Direct
2023-05-03	Common Stock	S	15000	$119.0081	Disposed	45085.145	Direct
2023-05-03	Common Stock	S	12000	$119.0074	Disposed	33085.145	Direct
2023-05-03	Common Stock	M	12000	$75.36	Acquired	45085.145	Direct
2023-05-03	Common Stock	S	13400	$119.01	Disposed	31685.145	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2023-05-03	Stock Option (Right to Buy)	$77.62	M	13000	Disposed	2029-05-02	Common Stock (13000)	Direct
2023-05-03	Stock Option (Right to Buy)	$73.73	M	12000	Disposed	2031-05-03	Common Stock (12000)	Direct
2023-05-03	Stock Option (Right to Buy)	$75.36	M	15000	Disposed	2030-04-30	Common Stock (15000)	Direct
2023-05-03	Stock Option (Right to Buy)	$75.36	M	12000	Disposed	2030-04-30	Common Stock (12000)	Direct

Footnotes

F1: These exercise and sale transactions were made pursuant to a Rule 10b5-1 trading plan adopted on February 13, 2023.

F2: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $119.0000 to $119.1300, inclusive. The reporting person undertakes to provide to Merck & Co., Inc., any security holder of Merck & Co., Inc. or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above in this footnote.

F3: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $119.0000 to $119.0600, inclusive. The reporting person undertakes to provide to Merck & Co., Inc., any security holder of Merck & Co., Inc. or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above in this footnote.

F4: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $119.0000 to $119.0800, inclusive. The reporting person undertakes to provide to Merck & Co., Inc., any security holder of Merck & Co., Inc. or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above in this footnote.

F5: Exercise price and holdings reflect the adjustments that occurred as of June 2, 2021 in connection with the Organon & Co. ("Organon") spin-off as described in the registration statement on Form 10 filed with the SEC by Organon (the "Form 10"). As reported in the Form 10, all Merck stock option awards outstanding as of immediately prior to the distribution date were converted on the distribution date into adjusted Merck awards for Merck employees to preserve the same intrinsic value and general terms and conditions (including vesting) as were in place immediately prior to the adjustments.

F6: The option vests and becomes exercisable in three equal installments on 5/3/2020, 5/3/2021 and 5/3/2022.

F7: The option vests and becomes exercisable in three equal installments on 5/4/2022, 5/4/2023 and 5/4/2024.

F8: The option vests and becomes exercisable in three equal installments on 5/1/2021, 5/1/2022 and 5/1/2023.