MKS INC Stock Compensation Disclosure

Employee Stock Purchase Plans

The 2014 ESPP was adopted by the Board of Directors on February 10, 2014 and approved by the Company’s stockholders on May 5, 2014. The 2014 ESPP authorizes the issuance of up to an aggregate of 2.5 shares of common stock to participating employees. Offerings under the 2014 ESPP commence on June 1 and December 1 and terminate on November 30 and May 31, respectively. Under the 2014 ESPP, eligible employees can purchase shares of common stock through payroll deductions up to 10% of their compensation, up to a defined maximum annual amount. The price at which an employee’s purchase option is exercised for each offering period is the lower of (1) 90% of the closing price of the common stock on the Nasdaq Global Select Market on the day that the offering commences, or (2) 90% of the closing price of the common stock on the day that the offering terminates. The Company issued 0.1 shares of common stock during each of 2025, 2024 and 2023 to employees who participated in the 2014 ESPP at exercise prices of $74.24 and $73.97 per share in 2025, $102.28 and $75.77 per share in 2024, and $74.95 and $74.30 per share in 2023. The Company recorded an immaterial amount of compensation expense related to the 2014 ESPP in 2025, 2024 and 2023. As of December 31, 2025, there were 1.2 shares reserved for future issuance under the 2014 ESPP.

Equity Incentive Plans

The Company grants RSUs to employees and directors under the 2022 Stock Incentive Plan (the “Plan”). The Plan is administered by the Compensation Committee of the Company's Board of Directors. The Plan is intended to attract and retain employees and directors, and to provide an incentive for these individuals to assist the Company to achieve long-range performance goals and enable these individuals to participate in the long-term growth of the Company. Up to 6.6 shares of common stock (subject to adjustment in the event of stock splits and other similar events) may be issued pursuant to awards granted under the Plan. The Company may grant options, RSUs, restricted stock, stock appreciation rights (“SARs”) and other stock-based awards to employees, officers, directors, consultants and advisors under the Plan. Any full-value awards granted under the Plan will be counted against the shares reserved for issuance under the Plan as 1.91 shares for each share of common stock subject to such award. Any award granted under the 2022 Plan that is not a full-value award (including, without limitation, any option or SAR) will be counted against the shares reserved for issuance under the plan on a one-for-one basis of common stock subject to such award. “Full-value award” means any restricted stock, RSUs, or other stock-based award with a per share price or per unit purchase price lower than 100% of fair market value on the date of grant. To the extent an award that is not a full-value award is returned to the Plan, the share reserve under the Plan will be credited with one share. To the extent that a full-value award is returned to the Plan, the share reserve under the Plan will be credited with 1.91 shares. As of December 31, 2025, there were 2.6 shares reserved for future issuance under the Plan.

Stock-Based Compensation Expense

The Company recognized the full impact of its share-based payment plans in the consolidated statements of operations and comprehensive income (loss). The following table reflects the effect of recording stock-based compensation: