Mayampurath Ramakumar

SEC source: 0001049502-26-000090 · form4.xml · nonDerivative · entry 1

Mayampurath Ramakumar · CIK 0001859332 · EVP & CFO

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 1.139

F1 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on February 20, 2026.

SEC source: 0001049502-26-000020 · form4.xml · derivative · entry 6

Mayampurath Ramakumar · CIK 0001859332 · EVP & CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 23,898.453

Underlying: Common Stock · 2,702 shares

Expires not disclosed

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 (RSU) represents the contingent right to receive one share of common stock of MKS Inc.

F1 · price: Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc.

F5 · derivative.exercise_date: These RSUs vest in three equal annual installments commencing on February 15, 2026, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F5 · derivative.expiration_date: These RSUs vest in three equal annual installments commencing on February 15, 2026, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001049502-26-000020 · form4.xml · derivative · entry 5

Mayampurath Ramakumar · CIK 0001859332 · EVP & CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 26,600.453

Underlying: Common Stock · 2,958.08 shares

Expires not disclosed

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 (RSU) represents the contingent right to receive one share of common stock of MKS Inc.

F1 · price: Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc.

F4 · derivative.exercise_date: These RSUs were subject to performance criteria, the achievement of which was determined on February 8, 2026, and thereafter vest in three equal annual installments beginning on February 15, 2026, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F4 · derivative.expiration_date: These RSUs were subject to performance criteria, the achievement of which was determined on February 8, 2026, and thereafter vest in three equal annual installments beginning on February 15, 2026, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001049502-26-000020 · form4.xml · derivative · entry 4

Mayampurath Ramakumar · CIK 0001859332 · EVP & CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 29,558.533

Underlying: Common Stock · 4,278.543 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc.

F1 · price: Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc.

F3 · derivative.exercise_date: These RSUs vest in three equal annual installments commencing on February 15, 2027, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F3 · derivative.expiration_date: These RSUs vest in three equal annual installments commencing on February 15, 2027, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001049502-26-000020 · form4.xml · nonDerivative · entry 3

Mayampurath Ramakumar · CIK 0001859332 · EVP & CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,811.139

F2 · kind: These shares were withheld by MKS Inc. to satisfy the tax withholding obligations triggered by the vesting of RSUs and do not represent a discretionary trade by the reporting person.

SEC source: 0001049502-26-000020 · form4.xml · nonDerivative · entry 2

Mayampurath Ramakumar · CIK 0001859332 · EVP & CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 11,327.08

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.

F1 · price: Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc.

SEC source: 0001049502-26-000020 · form4.xml · nonDerivative · entry 1

Mayampurath Ramakumar · CIK 0001859332 · EVP & CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,625.08

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.

F1 · price: Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc.

SEC source: 0001049502-26-000004 · form4.xml · derivative · entry 1

Mayampurath Ramakumar · CIK 0001859332 · EVP & CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 25,279.99

Underlying: Common Stock · 8,877.596 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc.

F1 · price: Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc.

F2 · derivative.exercise_date: These RSUs were subject to performance criteria, the achievement of which was determined on February 8, 2026, and thereafter vest in three equal annual installments beginning on February 15, 2026, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F2 · derivative.expiration_date: These RSUs were subject to performance criteria, the achievement of which was determined on February 8, 2026, and thereafter vest in three equal annual installments beginning on February 15, 2026, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001049502-25-000039 · form4.xml · derivative · entry 3

Mayampurath Ramakumar · CIK 0001859332 · EVP & CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 16,402.394

Underlying: Common Stock · 8,295 shares

Expires not disclosed

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 (RSU) represents the contingent right to receive one share of common stock of MKS Inc.

F1 · price: Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc.

F3 · derivative.exercise_date: These RSUs vest in two equal annual installments commencing on November 15, 2025, provided that if, in any vesting year, November 15th is not a business day, such vesting shall occur on the next business day.

F3 · derivative.expiration_date: These RSUs vest in two equal annual installments commencing on November 15, 2025, provided that if, in any vesting year, November 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001049502-25-000039 · form4.xml · nonDerivative · entry 2

Mayampurath Ramakumar · CIK 0001859332 · EVP & CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 5,667

F2 · kind: These shares were withheld by MKS Inc. to satisfy the tax withholding obligations triggered by the vesting of RSUs and do not represent a discretionary trade by the reporting person.

SEC source: 0001049502-25-000039 · form4.xml · nonDerivative · entry 1

Mayampurath Ramakumar · CIK 0001859332 · EVP & CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,295

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: Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc.

SEC source: 0001127602-25-005638 · form4.xml · derivative · entry 1

Mayampurath Ramakumar · CIK 0001859332 · EVP, CFO & Treasurer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 24,697.394

Underlying: Common Stock · 8,106.571 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F2 · derivative.exercise_date: These RSUs vest in three equal annual installments commencing on February 15, 2026, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F2 · derivative.expiration_date: These RSUs vest in three equal annual installments commencing on February 15, 2026, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-24-027461 · form4.xml · derivative · entry 1

Mayampurath Ramakumar · CIK 0001859332 · EVP, CFO & Treasurer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 16,590.823

Underlying: Common Stock · 16,590.823 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F2 · derivative.exercise_date: These RSUs vest in two equal annual installments commencing on November 15, 2025, provided that if, in any vesting year, November 15th is not a business day, such vesting shall occur on the next business day.

F2 · derivative.expiration_date: These RSUs vest in two equal annual installments commencing on November 15, 2025, provided that if, in any vesting year, November 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001664272-24-000239 · f4_a1edp0000016ph8mam-live.xml · nonDerivative · entry 1

Mayampurath Ramakumar · CIK 0001859332 · SVP, CFO, Treasurer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,626

F1 · shares: Shares withheld by the Company to satisfy tax withholding requirements on vesting of time-based restricted stock units.

SEC source: 0001664272-24-000104 · f4_a1e2k00000wi7xeuad-live.xml · nonDerivative · entry 1

Mayampurath Ramakumar · CIK 0001859332 · SVP, CFO, Treasurer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,706

F1 · shares: Represents the award of Time-Based Restricted Stock Units that convert to common stock on a one-for-one basis pursuant to the 2019 Long-Term Equity Compensation Plan. This Time-Based Restricted Stock Unit award vests in equal one-third increments on each of the first three (3) anniversaries of the Grant Date, provided that the Grantee is then employed by the Company or an Affiliate. Restricted Stock Units that are unvested as of the date of the Grantee's employment termination for any reason other than death, disability, or retirement shall be forfeited. If the Grantee dies, becomes disabled or retires prior to the third anniversary of the Grant Date, a pro-rated amount of the remaining unvested stock units in the grant would vest.

SEC source: 0001664272-24-000094 · f4_a1e2k00000wi7rwuat-live.xml · nonDerivative · entry 1

Mayampurath Ramakumar · CIK 0001859332 · SVP, CFO, Treasurer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 16,436

F1 · shares: Shares withheld by the Company to satisfy tax withholding requirements on vesting of time-based restricted stock units.

SEC source: 0001664272-24-000084 · f4_a1e2k00000wi7imua1-live.xml · nonDerivative · entry 1

Mayampurath Ramakumar · CIK 0001859332 · SVP, CFO, Treasurer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 16,727

F1 · shares: Shares withheld by the Company to satisfy tax withholding requirements on vesting of time-based restricted stock units.

SEC source: 0001664272-24-000084 · f4_a1e2k00000wi7imua1-live.xml · nonDerivative · entry 2

Mayampurath Ramakumar · CIK 0001859332 · SVP, CFO, Treasurer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 16,769

F1 · shares: Shares withheld by the Company to satisfy tax withholding requirements on vesting of time-based restricted stock units.

SEC source: 0001664272-23-000314 · f4_a1e2k00000rxsmeuad-live.xml · nonDerivative · entry 1

Mayampurath Ramakumar · CIK 0001859332 · SVP, CFO, Treasurer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 17,152

F1 · price: This is the weighted average sale price representing 1,200 shares sold at prices ranging from $160.680 to $161.355. The number of shares sold at each separate price will be made available to the SEC staff, the Company, or any security holder of the Company upon request.

SEC source: 0001664272-23-000312 · f4_a1e2k00000rxslguad-live.xml · nonDerivative · entry 1

Mayampurath Ramakumar · CIK 0001859332 · SVP, CFO, Treasurer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 18,352

F1 · shares: Shares withheld by the Company to satisfy tax withholding requirements on vesting of time-based restricted stock units.

SEC source: 0001664272-23-000079 · f4_a1e2k00000rxqquuat-live.xml · nonDerivative · entry 1

Mayampurath Ramakumar · CIK 0001859332 · SVP, CFO, Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 18,435

F1 · shares: Shares withheld by the Company to satisfy tax withholding requirements on vesting of time-based restricted stock units.

SEC source: 0001664272-23-000068 · f4_a1e2k00000rxqq0uad-live.xml · nonDerivative · entry 1

Mayampurath Ramakumar · CIK 0001859332 · SVP, CFO, Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 18,751

F1 · shares: Shares withheld by the Company to satisfy tax withholding requirements on vesting of time-based restricted stock units.

SEC source: 0001664272-23-000068 · f4_a1e2k00000rxqq0uad-live.xml · nonDerivative · entry 2

Mayampurath Ramakumar · CIK 0001859332 · SVP, CFO, Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 18,798

F1 · shares: Shares withheld by the Company to satisfy tax withholding requirements on vesting of time-based restricted stock units.

SEC source: 0001664272-23-000061 · f4_a1e2k00000rxqkluad-live.xml · nonDerivative · entry 3

Mayampurath Ramakumar · CIK 0001859332 · SVP, CFO, Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 18,849

F3 · shares: Represents the award of Time-Based Restricted Stock Units that convert to common stock on a one-for-one basis pursuant to the 2019 Long-Term Equity Compensation Plan. This Time-Based Restricted Stock Unit award vests in equal one-third increments on each of the first three (3) anniversaries of the Grant Date, provided that the Grantee is then employed by the Company or an Affiliate. Restricted Stock Units that are unvested as of the date of the Grantee's employment termination for any reason other than death, disability, or retirement shall be forfeited. If the Grantee dies, becomes disabled or retires prior to the third anniversary of the Grant Date, a pro-rated amount of the remaining unvested stock units in the grant would vest.

SEC source: 0001664272-23-000061 · f4_a1e2k00000rxqkluad-live.xml · nonDerivative · entry 2

Mayampurath Ramakumar · CIK 0001859332 · SVP, CFO, Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 15,125

F2 · shares: Shares withheld by the Company to satisfy tax withholding requirements on vesting of performance-based restricted stock units.

SEC source: 0001664272-23-000061 · f4_a1e2k00000rxqkluad-live.xml · nonDerivative · entry 1

Mayampurath Ramakumar · CIK 0001859332 · SVP, CFO, Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 15,162

F1 · shares: Vesting of performance-based restricted stock unit award.

SEC source: 0001664272-22-000350 · f4_a1e2k00000rxpiwua1-live.xml · nonDerivative · entry 1

Mayampurath Ramakumar · CIK 0001859332 · SVP, CFO, Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 15,053

F1 · shares: Represents the award of Time-Based Restricted Stock Units that convert to common stock on a one-for-one basis pursuant to the 2019 Long-Term Equity Compensation Plan. This Time-Based Restricted Stock Unit award vests fifty percent (50%) on the second anniversary of the Grant Date and fifty percent (50%) on the third anniversary of the Grant Date.

SEC source: 0001664272-22-000236 · f4_a1e2k00000rxlzvuad-live.xml · nonDerivative · entry 1

Mayampurath Ramakumar · CIK 0001859332 · SVP, CFO, Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,523

F1 · shares: Shares withheld by the Company to satisfy tax withholding requirements on vesting of time-based restricted stock units.

SEC source: 0001664272-22-000097 · f4_a1e2k00000rxkzvua1-live.xml · nonDerivative · entry 1

Mayampurath Ramakumar · CIK 0001859332 · SVP, CFO, Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,611

F1 · shares: Represents the award of Time-Based Restricted Stock Units that convert to common stock on a one-for-one basis pursuant to the 2019 Long-Term Equity Compensation Plan. This Time-Based Restricted Stock Unit award vests in equal one-third increments on each of the first three (3) anniversaries of the Grant Date, provided that the Grantee is then employed by the Company or an Affiliate. Restricted Stock Units that are unvested as of the date of the Grantee's employment termination for any reason other than death, disability, or retirement shall be forfeited. If the Grantee dies, becomes disabled or retires prior to the third anniversary of the Grant Date, a pro-rated amount of the remaining unvested stock units in the grant would vest.

SEC source: 0001664272-22-000074 · f4_a1e2k00000rxkyxua1-live.xml · nonDerivative · entry 1

Mayampurath Ramakumar · CIK 0001859332 · SVP, CFO, Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,361

F1 · shares: Shares withheld by the Company to satisfy tax withholding requirements on vesting of time-based restricted stock units.

SEC source: 0001664272-22-000065 · f4_a1e2k00000rxkxpua1-live.xml · nonDerivative · entry 1

Mayampurath Ramakumar · CIK 0001859332 · SVP, CFO, Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,403

F1 · shares: Shares withheld by the Company to satisfy tax withholding requirements on vesting of time-based restricted stock units.

SEC source: 0001664272-22-000056 · f4_a1e2k00000rxkwgual-live.xml · nonDerivative · entry 2

Mayampurath Ramakumar · CIK 0001859332 · SVP, CFO, Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,449

F2 · shares: Shares withheld by the Company to satisfy tax withholding requirements on vesting of performance-based restricted stock units.

SEC source: 0001664272-22-000056 · f4_a1e2k00000rxkwgual-live.xml · nonDerivative · entry 1

Mayampurath Ramakumar · CIK 0001859332 · SVP, CFO, Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,755

F1 · shares: Vesting of performance-based restricted stock unit award.

SEC source: 0001664272-22-000037 · f4_a1e2k00000rxkvyua1-live.xml · nonDerivative · entry 1

Mayampurath Ramakumar · CIK 0001859332 · SVP, CFO, Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,750

F1 · shares: Shares withheld by the Company to satisfy tax withholding requirements on vesting of time-based restricted stock units.

SEC source: 0001664272-21-000146 · f4_a1e2k00000h7ptpuaf-live.xml · nonDerivative · entry 1

Mayampurath Ramakumar · CIK 0001859332 · SVP, CFO, Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,815

F1 · shares: Represents the award of Time-Based Restricted Stock Units that convert to common stock on a one-for-one basis pursuant to the 2019 Long-Term Equity Compensation Plan. This Time-Based Restricted Stock Unit award vests in equal one-third increments on each of the first three (3) anniversaries of the Grant Date, provided that the Grantee is then employed by the Company or an Affiliate. Restricted Stock Units that are unvested as of the date of the Grantee's employment termination for any reason other than death, disability, or retirement shall be forfeited. If the Grantee dies, becomes disabled or retires prior to the third anniversary of the Grant Date, a pro-rated amount of the remaining unvested stock units in the grant would vest.