=== SEC Form 4 — Statement of Changes in Beneficial Ownership ===
Document Type: 4
Period of Report: 2026-08-05
10b5-1 Pre-arranged Plan: No
--- Issuer ---
Name: Merck & Co., Inc. (MRK)
CIK: 0000310158
--- Reporting Owner ---
Name: Williams David Michael
CIK: 0001820958
Role: Officer (EVP,Chief Info&Digital Officer)
--- Non-Derivative Transactions ---
[Transaction #1]
Security: Common Stock
Date: 2026-08-05 | Code: M (Exercise of derivative)
Shares: +4,600 | Price: $77.62
Total Value: $357,052.00
Shares Owned After: 36,316.037 | Ownership: D (Direct)
[Transaction #2]
Security: Common Stock
Date: 2026-08-05 | Code: S (Open market sale)
Shares: -4,600 | Price: $128.77
Total Value: $592,345.22
Shares Owned After: 31,716.037 | Ownership: D (Direct)
Footnotes:
[F1] The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $128.7050 to $128.9700, 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.
[Transaction #3]
Security: Common Stock
Date: 2026-08-05 | Code: M (Exercise of derivative)
Shares: +13,542 | Price: $75.36
Total Value: $1,020,525.12
Shares Owned After: 45,258.037 | Ownership: D (Direct)
[Transaction #4]
Security: Common Stock
Date: 2026-08-05 | Code: S (Open market sale)
Shares: -13,542 | Price: $128.77
Total Value: $1,743,812.82
Shares Owned After: 31,716.037 | Ownership: D (Direct)
Footnotes:
[F1] The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $128.7050 to $128.9700, 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.
[Transaction #5]
Security: Common Stock
Date: 2026-08-05 | Code: M (Exercise of derivative)
Shares: +34,705 | Price: $73.73
Total Value: $2,558,799.65
Shares Owned After: 66,421.037 | Ownership: D (Direct)
[Transaction #6]
Security: Common Stock
Date: 2026-08-05 | Code: S (Open market sale)
Shares: -34,705 | Price: $128.77
Total Value: $4,468,987.14
Shares Owned After: 31,716.037 | Ownership: D (Direct)
Footnotes:
[F1] The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $128.7050 to $128.9700, 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.
--- Derivative Transactions ---
[Transaction #1]
Security: Stock Option (Right to Buy)
Date: 2026-08-05 | Code: M (Exercise of derivative)
Shares: -4,600 | Price: $0.00
Exercisable: N/A | Expires: 2029-05-02
Shares Owned After: 0 | Ownership: D (Direct)
Footnotes:
[F2] The option vested and became exercisable in three equal installments on 5/3/2020, 5/3/2021, and 5/3/2022.
[Transaction #2]
Security: Stock Option (Right to Buy)
Date: 2026-08-05 | Code: M (Exercise of derivative)
Shares: -13,542 | Price: $0.00
Exercisable: N/A | Expires: 2030-04-30
Shares Owned After: 0 | Ownership: D (Direct)
Footnotes:
[F3] 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.
[F4] The option vested and became exercisable in three equal installments on 5/1/2021, 5/1/2022 and 5/1/2023.
[Transaction #3]
Security: Stock Option (Right to Buy)
Date: 2026-08-05 | Code: M (Exercise of derivative)
Shares: -34,705 | Price: $0.00
Exercisable: N/A | Expires: 2031-05-03
Shares Owned After: 0 | Ownership: D (Direct)
Footnotes:
[F3] 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.
[F5] The option vested and became exercisable in three equal installments on 5/4/2022, 5/4/2023, and 5/4/2024.
--- Footnotes (Complete Index) ---
F1: The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $128.7050 to $128.9700, 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.
F2: The option vested and became exercisable in three equal installments on 5/3/2020, 5/3/2021, and 5/3/2022.
F3: 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.
F4: The option vested and became exercisable in three equal installments on 5/1/2021, 5/1/2022 and 5/1/2023.
F5: The option vested and became exercisable in three equal installments on 5/4/2022, 5/4/2023, and 5/4/2024.
--- Signature ---
/s/ /s/ Kelly E. W. Grez as Attorney-in-Fact for David Michael Williams (2026-08-07)
