MRK

SEC source: 0000310158-26-000086 · form4.xml · derivative · entry 3

Zachary Jennifer · CIK 0001737231 · EVP, General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 5,903

Underlying: Common Stock · 2,951 shares

Expires 2028-04-29

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of Merck & Co., Inc. common stock.

F2 · derivative.exercise_date: 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.

SEC source: 0000310158-26-000086 · form4.xml · nonDerivative · entry 2

Zachary Jennifer · CIK 0001737231 · EVP, General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 70,897.254

SEC source: 0000310158-26-000086 · form4.xml · nonDerivative · entry 1

Zachary Jennifer · CIK 0001737231 · EVP, General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 72,351.254

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000310158-26-000090 · form4.xml · derivative · entry 5

Smart Dalton E. III · CIK 0002003375 · SVP Fin. - Global Controller

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,889

Underlying: Common Stock · 944 shares

Expires 2028-04-29

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of Merck & Co., Inc. common stock.

F3 · derivative.exercise_date: 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.

SEC source: 0000310158-26-000090 · form4.xml · nonDerivative · entry 2

Smart Dalton E. III · CIK 0002003375 · SVP Fin. - Global Controller

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,832.315

SEC source: 0000310158-26-000090 · form4.xml · nonDerivative · entry 1

Smart Dalton E. III · CIK 0002003375 · SVP Fin. - Global Controller

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 9,156.315

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · balance_after: Holdings include shares acquired in dividend reinvestment transactions.

SEC source: 0000310158-26-000088 · form4.xml · derivative · entry 3

Li Dean Y · CIK 0001837016 · Executive VP & President, MRL

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 9,444

Underlying: Common Stock · 4,722 shares

Expires 2028-04-29

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of Merck & Co., Inc. common stock.

F2 · derivative.exercise_date: 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.

SEC source: 0000310158-26-000088 · form4.xml · nonDerivative · entry 2

Li Dean Y · CIK 0001837016 · Executive VP & President, MRL

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 94,431.05

SEC source: 0000310158-26-000088 · form4.xml · nonDerivative · entry 1

Li Dean Y · CIK 0001837016 · Executive VP & President, MRL

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 96,757.05

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000310158-26-000092 · form4.xml · derivative · entry 3

Williams David Michael · CIK 0001820958 · EVP,Chief Info&Digital Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 2,755

Underlying: Common Stock · 1,377 shares

Expires 2028-04-29

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of Merck & Co., Inc. common stock.

F3 · derivative.exercise_date: 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.

SEC source: 0000310158-26-000092 · form4.xml · nonDerivative · entry 2

Williams David Michael · CIK 0001820958 · EVP,Chief Info&Digital Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 31,716.037

SEC source: 0000310158-26-000092 · form4.xml · nonDerivative · entry 1

Williams David Michael · CIK 0001820958 · EVP,Chief Info&Digital Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 32,395.037

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · balance_after: Holdings include shares acquired in dividend reinvestment transactions.

SEC source: 0000310158-26-000096 · form4.xml · derivative · entry 4

DeLuca Richard R. · CIK 0001421339 · EVP&Pres, Merck Animal Heallth

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 5,037

Underlying: Common Stock · 2,518 shares

Expires 2028-04-29

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of Merck & Co., Inc. common stock.

F3 · derivative.exercise_date: 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.

SEC source: 0000310158-26-000096 · form4.xml · nonDerivative · entry 2

DeLuca Richard R. · CIK 0001421339 · EVP&Pres, Merck Animal Heallth

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 161,537.07

SEC source: 0000310158-26-000096 · form4.xml · nonDerivative · entry 1

DeLuca Richard R. · CIK 0001421339 · EVP&Pres, Merck Animal Heallth

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 162,778.07

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · balance_after: Holdings include shares acquired in dividend reinvestment transactions.

SEC source: 0000310158-26-000097 · form4.xml · derivative · entry 6

Chattopadhyay Sanat · CIK 0001670690 · Exe V-P & Pres. MMD

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 5,194

Underlying: Common Stock · 2,597 shares

Expires 2028-04-29

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F4 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of Merck & Co., Inc. common stock.

F5 · derivative.exercise_date: 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.

SEC source: 0000310158-26-000097 · form4.xml · nonDerivative · entry 2

Chattopadhyay Sanat · CIK 0001670690 · Exe V-P & Pres. MMD

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 15,347

SEC source: 0000310158-26-000097 · form4.xml · nonDerivative · entry 1

Chattopadhyay Sanat · CIK 0001670690 · Exe V-P & Pres. MMD

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 16,477

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000310158-26-000102 · form4.xml · derivative · entry 4

Guindo Chirfi · CIK 0001722753 · EVP, Access, Policy & Comms

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 3,935

Underlying: Common Stock · 1,967 shares

Expires 2028-04-29

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of Merck & Co., Inc. common stock.

F3 · derivative.exercise_date: 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.

SEC source: 0000310158-26-000102 · form4.xml · nonDerivative · entry 2

Guindo Chirfi · CIK 0001722753 · EVP, Access, Policy & Comms

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 61,613.127

SEC source: 0000310158-26-000102 · form4.xml · nonDerivative · entry 1

Guindo Chirfi · CIK 0001722753 · EVP, Access, Policy & Comms

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 62,582.127

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000310158-26-000074 · form4.xml · derivative · entry 2

Coe Mary Ellen · CIK 0001691304 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 29,702.6519

Underlying: Common Stock · 249.3973 shares

Expires not disclosed

F1 · derivative.exercise_price: 1-for-1

F2 · derivative.exercise_date: 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.

F2 · derivative.expiration_date: 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.

F3 · balance_after: Holdings include shares acquired in dividend reinvestment transactions.

SEC source: 0000310158-26-000075 · form4.xml · derivative · entry 2

GLOCER THOMAS H · CIK 0001140799 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 108,293.493

Underlying: Common Stock · 405.2706 shares

Expires not disclosed

F1 · derivative.exercise_price: 1-for-1

F2 · derivative.exercise_date: 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.

F2 · derivative.expiration_date: 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.

F3 · balance_after: Holdings include shares acquired in dividend reinvestment transactions.

SEC source: 0000310158-26-000076 · form4.xml · derivative · entry 2

Seidman Christine E · CIK 0001805745 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 19,238.3277

Underlying: Common Stock · 67.5451 shares

Expires not disclosed

F1 · derivative.exercise_price: 1-for-1

F2 · derivative.exercise_date: 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.

F2 · derivative.expiration_date: 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.

F3 · balance_after: Holdings include shares acquired in dividend reinvestment transactions.

SEC source: 0000310158-26-000052 · form4.xml · nonDerivative · entry 1

Guindo Chirfi · CIK 0001722753 · Chief Marketing Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 60,615.127

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $121.4400 to $121.5150, 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.

SEC source: 0000310158-26-000050 · form4.xml · nonDerivative · entry 1

Li Dean Y · CIK 0001837016 · Executive VP & President, MRL

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 92,035.05

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $117.5200 to $117.5550, 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.

SEC source: 0000310158-26-000046 · form4.xml · derivative · entry 9

Zachary Jennifer · CIK 0001737231 · EVP, General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 38,835 shares

Expires 2032-05-02

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F4 · derivative.exercise_date: The option vests and becomes exercisable in equal installments on 5/3/2023, 5/3/2024 and 5/3/2025.

SEC source: 0000310158-26-000046 · form4.xml · derivative · entry 8

Zachary Jennifer · CIK 0001737231 · EVP, General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 56,792 shares

Expires 2031-05-03

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_date: The option vests and becomes exercisable in three equal installments on 5/4/2022, 5/4/2023 and 5/4/2024.

SEC source: 0000310158-26-000046 · form4.xml · derivative · entry 7

Zachary Jennifer · CIK 0001737231 · EVP, General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 25,946 shares

Expires 2030-04-30

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_date: The option vested and became exercisable in three equal installments on 5/1/2021, 5/1/2022 and 5/1/2023.

SEC source: 0000310158-26-000046 · form4.xml · nonDerivative · entry 6

Zachary Jennifer · CIK 0001737231 · EVP, General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 68,915.671

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $118.9600 to $119.5100, 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.

SEC source: 0000310158-26-000046 · form4.xml · nonDerivative · entry 5

Zachary Jennifer · CIK 0001737231 · EVP, General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 107,750.671

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $118.9600 to $119.5100, 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.

SEC source: 0000310158-26-000046 · form4.xml · nonDerivative · entry 4

Zachary Jennifer · CIK 0001737231 · EVP, General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 68,915.671

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $118.9600 to $119.5100, 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.

SEC source: 0000310158-26-000046 · form4.xml · nonDerivative · entry 3

Zachary Jennifer · CIK 0001737231 · EVP, General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 125,707.671

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $118.9600 to $119.5100, 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.

SEC source: 0000310158-26-000046 · form4.xml · nonDerivative · entry 2

Zachary Jennifer · CIK 0001737231 · EVP, General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 68,915.671

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $118.9600 to $119.5100, 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.

SEC source: 0000310158-26-000046 · form4.xml · nonDerivative · entry 1

Zachary Jennifer · CIK 0001737231 · EVP, General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 94,861.671

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $118.9600 to $119.5100, 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.

SEC source: 0000310158-26-000048 · form4.xml · nonDerivative · entry 1

Guindo Chirfi · CIK 0001722753 · Chief Marketing Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 70,615.127

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $118.4000 to $118.4502, 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.

SEC source: 0000310158-26-000032 · form4.xml · nonDerivative · entry 1

DeLuca Richard R. · CIK 0001421339 · EVP&Pres, Merck Animal Heallth

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 160,173.834

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $120.7350 to $121.3054, 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.

SEC source: 0000310158-26-000040 · form4.xml · nonDerivative · entry 1

Oosthuizen Johannes Jacobus · CIK 0001916310 · President, U.S. Market

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 21,197.389

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $121.8200 to $121.9500, 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.

SEC source: 0000310158-26-000044 · form4.xml · derivative · entry 3

Williams David Michael · CIK 0001820958 · EVP,Chief Info&Digital Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 4,600

Underlying: Common Stock · 5,000 shares

Expires 2029-05-02

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: 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.

F2 · derivative.exercise_date: The option vests and becomes exercisable in three equal installments on 5/3/2020, 5/3/2021 and 5/3/2022.

SEC source: 0000310158-26-000044 · form4.xml · nonDerivative · entry 2

Williams David Michael · CIK 0001820958 · EVP,Chief Info&Digital Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 30,837.743

SEC source: 0000310158-26-000044 · form4.xml · nonDerivative · entry 1

Williams David Michael · CIK 0001820958 · EVP,Chief Info&Digital Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 35,837.743

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000310158-26-000034 · form4.xml · nonDerivative · entry 1

Guindo Chirfi · CIK 0001722753 · Chief Marketing Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 80,615.127

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $121.8400 to $121.9700, 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.

SEC source: 0000310158-26-000030 · form4.xml · nonDerivative · entry 2

Davis Robert M · CIK 0001363076 · Director · Chairman, CEO & President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 443,601.757

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $118.0000 to $118.7100, 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.

SEC source: 0000310158-26-000030 · form4.xml · nonDerivative · entry 1

Davis Robert M · CIK 0001363076 · Director · Chairman, CEO & President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 476,063.757

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $116.9600 to $117.9500, 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.

SEC source: 0000310158-26-000036 · form4.xml · derivative · entry 3

Li Dean Y · CIK 0001837016 · Executive VP & President, MRL

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 15,087 shares

Expires 2028-05-03

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: 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.

F3 · derivative.exercise_date: The option became exercisable in equal installments on 5/4/2019, 5/4/2020, and 5/4/2021.

SEC source: 0000310158-26-000036 · form4.xml · nonDerivative · entry 2

Li Dean Y · CIK 0001837016 · Executive VP & President, MRL

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 102,270.05

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $118.7200 to $118.8300, 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 in this footnote.

SEC source: 0000310158-26-000036 · form4.xml · nonDerivative · entry 1

Li Dean Y · CIK 0001837016 · Executive VP & President, MRL

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 117,357.05

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0000310158-26-000038 · form4.xml · derivative · entry 3

Litchfield Caroline · CIK 0001854928 · EVP & CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 41,997 shares

Expires 2026-05-09

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: 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.

F3 · derivative.exercise_date: The option became exercisable in equal installments on 5/10/2017, 5/10/2018 and 5/10/2019.

SEC source: 0000310158-26-000038 · form4.xml · nonDerivative · entry 2

Litchfield Caroline · CIK 0001854928 · EVP & CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 90,192.194

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $119.5400 to $119.7800, 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.

SEC source: 0000310158-26-000038 · form4.xml · nonDerivative · entry 1

Litchfield Caroline · CIK 0001854928 · EVP & CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 132,189.194

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.