M K S I N S T R U M E N T S A N N U A L R E P O R T 2 0 2 3 ANNUAL REPORT 2023 Enabling Technologies That Transform Our World At MKS, we have a long history of leveraging our collective curiosity to understand and develop solutions that are at the core of many key technological innovations. These innovations have driven accelerated roadmaps for semiconductor manufacturing, electronics and packaging, and specialty industrial applications. Our mission is to be the innovation leader and trusted partner that pushes the boundaries of possibility. To Our Shareholders MKS’ performance in 2023 highlighted the Of course, our strategic positioning must be resilience of our business through a soft demand complemented by strong business execution. In environment for products where we play a 2023, we delivered on our innovation roadmaps, foundational role, including memory chips and controlled costs, managed our balance sheet, and other critical electronic components that enable secured design wins with key customers, all of advanced electronic devices, such as PCs, which are critical to generating attractive growth smartphones and servers. MKS is structured to and value creation in the years ahead. It is worth manage through cycles with a broad portfolio noting that we achieved these goals despite the of differentiated, proprietary solutions that offer ransomware incident we experienced in early attractive profit margins, and a culture of prudent 2023. I am both humbled by and grateful for the cost control. way our global team rallied to contain this issue, communicated transparently with customers and 2023 also marked our first full year operating with successfully restored normal business operations. Atotech. Atotech’s industry-leading chemistry and plating equipment solutions augment our broad The strength of our team and culture is a running range of leading technologies, uniquely position theme at MKS, and recently this was reflected us within the Electronics & Packaging market, in industry accolades we received, such as and provide us with a higher mix of more stable being named to US News and World Report’s consumables and services revenue. We are on inaugural “Best Companies to Work for in the track to achieve our target post-acquisition cost Industrials and Business Services Industry” synergies and have increased engagement with list, as well as being named by Newsweek and combined customers of MKS and Atotech on Statista as one of “America’s Most Responsible next-generation designs for advanced package Companies for 2024.” substrates, a critical enabler for new applications, such as artificial intelligence. We remain excited We are excited to continue to deliver innovations about revenue opportunities that leverage Atotech’s business within our broader portfolio. that are foundational to the next generation of advanced electronic devices. We appreciate the continued support of our customers, who rely With most industry observers expecting a recovery on MKS to solve their toughest challenges, our in our end markets to slowly unfold in the second shareholders, who have placed their trust in MKS half of 2024, we believe MKS is prepared to to deliver value creation, and our employees, who capture exciting new opportunities. We have work relentlessly to deliver on the MKS promise. continued to invest in our business, strengthening our position as a critical enabler of advanced electronics with our foundational solutions for the Semiconductor and Electronics & Packaging markets. Our leading applications within our Specialty Industrial portfolio extend our reach into additional markets and generate attractive cash flow for our business. In 2023, we delivered on our innovation roadmaps, controlled costs, managed our balance sheet, and secured design wins with key customers, all of which are critical to generating attractive growth and value creation in the years ahead. John T.C. Lee President and Chief Executive Officer Madhuri A. Andrews EVP and CIO Seth H. Bagshaw EVP, CFO and Treasurer Sally Ann Bouley EVP and CHRO Kathleen F. Burke EVP, General Counsel and Secretary Henry C. Chang SVP and GM, Asia Mark M. Gitin EVP and GM, Photonics Solutions Division David P. Henry EVP, Operations and Corporate Marketing James A. Schreiner EVP and COO, Materials Solutions Division Eric R. Taranto EVP and GM, Vacuum Solutions Division Cautionary Statement Regarding Forward-Looking Statements This Annual Report contains “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934 regarding the future financial performance, business prospects and growth of MKS Instruments, Inc. (“MKS,” the “Company,” “our,” or “we”). These statements are only predictions based on current assumptions and expectations. Any statements that are not statements of historical fact (including statements containing the words “will,” “projects,” “intends,” “believes,” “plans,” “anticipates,” “expects,” “estimates,” “forecasts,” “continues” and similar expressions) should be considered to be forward-looking statements. Actual events or results may differ materially from those in the forward-looking statements set forth herein. Among the important factors that could cause actual events to differ materially from those in the forward-looking statements that we make are the need to generate sufficient cash flows to service and repay the substantial indebtedness we incurred in connection with our acquisition of Atotech Limited (“Atotech” and such transaction, the “Atotech Acquisition”), which we completed in August 2022; the terms of our existing credit facilities under which we incurred such debt; our entry into the chemicals technology business through the Atotech Acquisition, in which we did not have previous experience and which may expose us to significant additional liabilities; the risk that we are unable to integrate the Atotech Acquisition successfully or realize the anticipated synergies, cost savings and other benefits of the Atotech Acquisition; legal, reputational, financial and contractual risks resulting from the ransomware incident we identified in February 2023, and other risks related to cybersecurity, data privacy and intellectual property; competition from larger, more advanced or more established companies in our markets; the ability to successfully grow our business, including through growth of the Atotech business and growth of the Electro Scientific Industries, Inc. business, which we acquired in February 2019, and financial risks associated with those and potential future acquisitions, including goodwill and intangible asset impairments; manufacturing and sourcing risks, including those associated with limited and sole source suppliers and the impact and duration of supply chain disruptions, component shortages, and price increases; changes in global demand; the impact of a pandemic or other widespread health crisis; risks associated with doing business internationally, including geopolitical conflicts, such as the conflict in the Middle East, trade compliance, regulatory restrictions on our products, components or markets, particularly the semiconductor market, and unfavorable currency exchange and tax rate fluctuations, which risks become more significant as we grow our business internationally and in China specifically; conditions affecting the markets in which we operate, including fluctuations in capital spending in the semiconductor, electronics manufacturing and automotive industries, and fluctuations in sales to our major customers; disruptions or delays from third-party service providers upon which our operations may rely; the ability to anticipate and meet customer demand; the challenges, risks and costs involved with integrating or transitioning global operations of the companies we have acquired; risks associated with the attraction and retention of key personnel; potential fluctuations in quarterly results; dependence on new product development; rapid technological and market change; acquisition strategy; volatility of stock price; risks associated with chemical manufacturing and environmental regulation compliance; risks related to defective products; financial and legal risk management; and the other important factors described in Part I, Item 1A of the Form 10-K for the year ended December 31, 2023 included in this Annual Report. We are under no obligation to, and expressly disclaim any obligation to, update or alter these forward-looking statements, whether as a result of new information, future events or otherwise, even if subsequent events cause our views to change. Board of Directors Gerald G. Colella Chairman MKS Instruments, Inc. Rajeev Batra President Siemens Industry Inc. and Member, Siemens U.S. Managing Board Peter J. Cannone III Chairman and Chief Executive Officer Demand Science Group, LLC Management John T.C. Lee President and Chief Executive Officer Madhuri A. Andrews Executive Vice President and Chief Information Officer Seth H. Bagshaw Executive Vice President, Chief Financial Officer and Treasurer* Sally Ann Bouley Executive Vice President and Chief Human Resources Officer *Retiring effective April 1, 2024. Corporate Headquarters MKS Instruments, Inc. 2 Tech Drive, Suite 201 Andover, MA 01810 Telephone: +1.978.645.5500 Outside Counsel Wilmer Cutler Pickering Hale and Dorr LLP Boston, MA Independent Auditors PricewaterhouseCoopers LLP Boston, MA Joseph B. Donahue Former Executive Vice President and Chief Operating Officer TE Connectivity Ltd. John T.C. Lee President and Chief Executive Officer MKS Instruments, Inc. Jacqueline F. Moloney Chancellor Emerita and Professor University of Massachusetts Lowell Elizabeth A. Mora Former Chief Administrative Officer The Charles Stark Draper Laboratory, Inc. Michelle M. Warner Executive Director CEO Perspectives Corporate Leadership Center, NFP Kathleen F. Burke Executive Vice President, General Counsel and Secretary Henry C. Chang Senior Vice President and General Manager, Asia Mark M. Gitin Executive Vice President and General Manager, Photonics Solutions Division David P. Henry Executive Vice President, Operations and Corporate Marketing James A. Schreiner Executive Vice President and Chief Operating Officer, Materials Solutions Division Eric R. Taranto Executive Vice President and General Manager, Vacuum Solutions Division Stock Listing Nasdaq Global Select Market Symbol: MKSI Transfer Agent Equiniti Trust Company, LLC 48 Wall Street, Floor 23 New York, NY 10005 Telephone: US: +1.800.937.5449 International: +718.921.8124 https://equiniti.com/us/ast-access/ Shareholders may also direct inquiries to: David Ryzhik Vice President, Investor Relations MKS Instruments, Inc. 2 Tech Drive, Suite 201 Andover, MA 01810 Telephone: +1.978.557.5180 www.mks.com Annual Meeting of Shareholders May 7, 2024, 10:00 a.m. EDT MKS Instruments, Inc. 2 Tech Drive, Suite 201 Andover, MA 01810 M K S I N S T R U M E N T S A N N U A L R E P O R T 2 0 2 3 MKS Instruments, Inc. +1 978.645.5500 www.mks.com