MRK

SEC source: 0001127602-22-024871 · form4.xml · nonDerivative · entry 2

FRAZIER KENNETH C · CIK 0001181175 · Director · Executive Chair

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 803,964.063

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $98.9700 to $99.9700, 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: 0001127602-22-024871 · form4.xml · nonDerivative · entry 1

FRAZIER KENNETH C · CIK 0001181175 · Director · Executive Chair

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,006,283.063

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: 0001127602-22-024610 · form4.xml · derivative · entry 10

FRAZIER KENNETH C · CIK 0001181175 · Director · Executive Chair

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 465,828

Underlying: Common Stock · 300,000 shares

Expires 2025-04-30

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.

F8 · 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.

F10 · derivative.exercise_date: The option became exercisable in equal installments on 5/1/2016, 5/1/2017 and 5/1/2018.

F8 · balance_after: 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.

SEC source: 0001127602-22-024610 · form4.xml · nonDerivative · entry 7

FRAZIER KENNETH C · CIK 0001181175 · Director · Executive Chair

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 706,283.063

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $100.3600 to $101.3100, 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.

F6 · balance_after: Holdings include shares acquired in dividend reinvestment transactions.

SEC source: 0001127602-22-024610 · form4.xml · nonDerivative · entry 6

FRAZIER KENNETH C · CIK 0001181175 · Director · Executive Chair

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 935,585.063

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $99.3300 to $100.3200, 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: 0001127602-22-024610 · form4.xml · nonDerivative · entry 5

FRAZIER KENNETH C · CIK 0001181175 · Director · Executive Chair

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,006,283.063

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: 0001127602-22-024599 · form4.xml · derivative · entry 4

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 915

Underlying: Common Stock · 913 shares

Expires 2023-10-30

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_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 10/30/2021, 10/30/2022 and 10/30/2023.

SEC source: 0001127602-22-024599 · form4.xml · nonDerivative · entry 3

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 11,343.881

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

SEC source: 0001127602-22-024599 · form4.xml · nonDerivative · entry 2

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 11,793.881

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: 0001127602-22-024595 · form4.xml · derivative · entry 8

Zachary Jennifer · CIK 0001737231 · EVP, General Counsel

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 56,792

Underlying: Common Stock · 28,396 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.

F4 · 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.

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

F4 · balance_after: 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.

SEC source: 0001127602-22-024595 · form4.xml · derivative · entry 7

Zachary Jennifer · CIK 0001737231 · EVP, General Counsel

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 25,946

Underlying: Common Stock · 51,884 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.

F4 · 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.

F6 · derivative.exercise_date: The option vests and becomes exercisable in three equal installments on 5/1/2021, 5/1/2022 and 5/1/2023.

F4 · balance_after: 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.

SEC source: 0001127602-22-024595 · form4.xml · derivative · entry 6

Zachary Jennifer · CIK 0001737231 · EVP, General Counsel

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 68,367 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.

F4 · 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.

F5 · derivative.exercise_date: The option vests and becomes exercisable in three equal installments on 5/3/2020, 5/3/2021 and 5/3/2022.

F4 · balance_after: 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.

SEC source: 0001127602-22-024595 · form4.xml · nonDerivative · entry 5

Zachary Jennifer · CIK 0001737231 · EVP, General Counsel

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 38,040.302

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $99.6100 to $100.3600, 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 · balance_after: Holdings include shares acquired in dividend reinvestment transactions.

SEC source: 0001127602-22-024595 · form4.xml · nonDerivative · entry 4

Zachary Jennifer · CIK 0001737231 · EVP, General Counsel

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 103,527.302

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $98.5500 to $99.4900, 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: 0001127602-22-024595 · form4.xml · nonDerivative · entry 3

Zachary Jennifer · CIK 0001737231 · EVP, General Counsel

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 203,295.302

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: 0001127602-22-024595 · form4.xml · nonDerivative · entry 2

Zachary Jennifer · CIK 0001737231 · EVP, General Counsel

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 174,899.302

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: 0001127602-22-024595 · form4.xml · nonDerivative · entry 1

Zachary Jennifer · CIK 0001737231 · EVP, General Counsel

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 123,015.302

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: 0001127602-22-024602 · form4.xml · derivative · entry 4

MIZELL STEVEN · CIK 0001189403 · EVP, Chief HR Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 35,824

Underlying: Common Stock · 17,000 shares

Expires 2028-10-29

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.

F3 · 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.

F4 · derivative.exercise_date: The option vested and became exercisable in three equal installments on 10/30/2019, 10/30/2020 and 10/30/2021.

F3 · balance_after: 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.

SEC source: 0001127602-22-024602 · form4.xml · nonDerivative · entry 3

MIZELL STEVEN · CIK 0001189403 · EVP, Chief HR Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 32,144.145

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $98.8400 to $98.8450, 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 · balance_after: Holdings include shares acquired in dividend reinvestment transactions.

SEC source: 0001127602-22-024602 · form4.xml · nonDerivative · entry 2

MIZELL STEVEN · CIK 0001189403 · EVP, Chief HR Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 40,144.145

SEC source: 0001127602-22-024602 · form4.xml · nonDerivative · entry 1

MIZELL STEVEN · CIK 0001189403 · EVP, Chief HR Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 57,144.145

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: 0001127602-22-024608 · form4.xml · derivative · entry 5

Karachun Rita A · CIK 0001601572 · Sr. VP Fince-Global Controller

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 15,875

Underlying: Common Stock · 15,000 shares

Expires 2027-05-04

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: 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 · derivative.exercise_date: The option became exercisable in equal installments on 5/5/2018, 5/5/2019 and 5/5/2020.

F4 · balance_after: 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.

SEC source: 0001127602-22-024608 · form4.xml · derivative · entry 4

Karachun Rita A · CIK 0001601572 · Sr. VP Fince-Global Controller

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 16,997 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.

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

SEC source: 0001127602-22-024608 · form4.xml · nonDerivative · entry 3

Karachun Rita A · CIK 0001601572 · Sr. VP Fince-Global Controller

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 41,102.972

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $100.2800 to $100.4700, 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 · balance_after: Holdings include shares acquired in dividend reinvestment transactions.

SEC source: 0001127602-22-024608 · form4.xml · nonDerivative · entry 2

Karachun Rita A · CIK 0001601572 · Sr. VP Fince-Global Controller

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 73,099.972

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: 0001127602-22-024608 · form4.xml · nonDerivative · entry 1

Karachun Rita A · CIK 0001601572 · Sr. VP Fince-Global Controller

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 58,099.972

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: 0001127602-22-024599 · form4.xml · nonDerivative · entry 1

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 10,880.881

SEC source: 0001127602-22-024610 · form4.xml · derivative · entry 9

FRAZIER KENNETH C · CIK 0001181175 · Director · Executive Chair

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 567,084 shares

Expires 2024-05-08

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.

F8 · 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.

F9 · derivative.exercise_date: The option became exercisable in equal installments on 5/9/2015, 5/9/2016 and 5/9/2017.

F8 · balance_after: 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.

SEC source: 0001127602-22-024610 · form4.xml · nonDerivative · entry 4

FRAZIER KENNETH C · CIK 0001181175 · Director · Executive Chair

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 706,283.063

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $100.6500 to $100.9725, 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: 0001127602-22-024610 · form4.xml · nonDerivative · entry 3

FRAZIER KENNETH C · CIK 0001181175 · Director · Executive Chair

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 884,646.063

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $99.6400 to $100.6400, 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: 0001127602-22-024610 · form4.xml · nonDerivative · entry 2

FRAZIER KENNETH C · CIK 0001181175 · Director · Executive Chair

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,197,878.063

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $98.6100 to $99.6000, inclusive. The reporting person undertakes to provide to Merck & Co., Inc., anysecurity 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: 0001127602-22-024610 · form4.xml · nonDerivative · entry 1

FRAZIER KENNETH C · CIK 0001181175 · Director · Executive Chair

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,273,367.063

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: 0001127602-22-024626 · form4.xml · derivative · entry 6

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 104,993 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.

F5 · 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.

F6 · derivative.exercise_date: The option became exercisable in equal installments on 5/10/2017, 5/10/2018 and 5/10/2019.

F5 · balance_after: 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.

SEC source: 0001127602-22-024626 · form4.xml · derivative · entry 5

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 59,564 shares

Expires 2025-04-30

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.

F4 · derivative.exercise_date: The option became exercisable in equal installments on 5/1/2016, 5/1/2017 and 5/1/2018.

SEC source: 0001127602-22-024626 · form4.xml · nonDerivative · entry 3

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 136,977.143

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $99.9100 to $100.5700, 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 · balance_after: Holdings include shares acquired in dividend reinvestment transactions.

SEC source: 0001127602-22-024626 · form4.xml · nonDerivative · entry 2

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 301,534.143

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: 0001127602-22-024626 · form4.xml · nonDerivative · entry 1

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 196,541.143

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: 0001127602-22-024629 · form4.xml · derivative · entry 8

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 51,055 shares

Expires 2025-04-30

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.

F5 · 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.

F7 · derivative.exercise_date: The option became exercisable in equal installments on 5/1/2016, 5/1/2017 and 5/1/2018.

F5 · balance_after: 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.

SEC source: 0001127602-22-024629 · form4.xml · derivative · entry 7

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 34,024 shares

Expires 2024-05-01

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.

F5 · 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.

F6 · derivative.exercise_date: The option became exercisable in equal installments on 5/2/2015, 5/2/2016 and 5/2/2017.

F5 · balance_after: 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.

SEC source: 0001127602-22-024629 · form4.xml · derivative · entry 6

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 15,213 shares

Expires 2023-05-05

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.

F4 · derivative.exercise_date: The option became exercisable in equal installments on 5/6/2014, 5/6/2015 and 5/6/2016.

SEC source: 0001127602-22-024629 · form4.xml · nonDerivative · entry 4

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 45,608.357

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $99.9650 to $100.3400, 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 · balance_after: Holdings include shares acquired in dividend reinvestment transactions.

SEC source: 0001127602-22-024629 · form4.xml · nonDerivative · entry 3

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 145,900.357

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: 0001127602-22-024629 · form4.xml · nonDerivative · entry 2

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 94,845.357

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: 0001127602-22-024629 · form4.xml · nonDerivative · entry 1

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 60,821.357

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: 0001127602-22-023381 · form4.xml · derivative · entry 2

GLOCER THOMAS H · CIK 0001140799 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 85,350.6914

Underlying: Common Stock · 522.5267 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: 0001127602-22-023378 · form4.xml · derivative · entry 2

Coe Mary Ellen · CIK 0001691304 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 16,662.7246

Underlying: Common Stock · 377.3804 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: 0001127602-22-023383 · form4.xml · derivative · entry 2

Seidman Christine E · CIK 0001805745 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 10,039.0078

Underlying: Common Stock · 94.3451 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: 0001127602-22-023387 · form4.xml · derivative · entry 2

WENDELL PETER C · CIK 0001032635 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 116,237.8582

Underlying: Common Stock · 348.3511 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: 0001127602-22-020468 · form4.xml · derivative · entry 2

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 17,119

Underlying: Common Stock · 17,119 shares

Expires 2025-08-03

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 8/3/2023, 8/3/2024 and 8/3/2025.

SEC source: 0001127602-22-020472 · form4.xml · derivative · entry 3

Guindo Chirfi · CIK 0001722753 · Chief Marketing Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 110,705

Underlying: Common Stock · 110,705 shares

Expires 2025-08-03

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 8/3/2023, 8/3/2024 and 8/3/2025.