EX-99.1

Selected GAAP and Non-GAAP Financial Measures

(In millions, except per share data)


	Q1 2026			Q4 2025			Q1 2025
Net Revenues
Semiconductor	$	466		$	435		$	413
Electronics & Packaging		321			303			253
Specialty Industrial		291			295			270
Total net revenues	$	1,078		$	1,033		$	936
Gross Margin		47.0	%		46.4	%		47.4	%
GAAP Financial Measures
Operating margin		13.8	%		13.9	%		11.9	%
Net income	$	84		$	108		$	52
Net income per diluted share	$	1.18		$	1.58		$	0.77
Non-GAAP Financial Measures
Operating margin		21.8	%		21.0	%		20.2	%
Net earnings	$	157		$	168		$	116
Net earnings per diluted share	$	2.30		$	2.47		$	1.71

Additional Financial Information

During the first quarter of 2026, the Company completed a private offering of €1.0 billion aggregate principal amount of 4.25% senior notes due 2034. The Company used the net proceeds from the offering, together with the net proceeds from the partial refinancing of its then-existing USD term loan B and refinancing of its then-existing EUR term loan B, both of which were also completed during the first quarter of 2026, and cash on hand to prepay approximately $1.3 billion of, and refinance in full, its existing USD term loan B and refinance in full its existing EUR term loan B. The Company also upsized its revolving credit facility from $675 million to $1.0 billion. In addition, the Company increased its dividend from $0.22 per share to $0.25 per share and paid a cash dividend of $17 million.

At March 31, 2026, the Company had $569 million in cash and cash equivalents, $1.6 billion of secured term loan principal outstanding, $1.4 billion of convertible senior notes outstanding, €1.0 billion of senior notes outstanding and up to $1.0 billion of additional borrowing capacity under a revolving credit facility, subject to certain leverage ratio requirements. The appreciation of our stock price during the first quarter of 2026 resulted in the satisfaction of the stock price conversion condition under the indenture governing our convertible senior notes. As a result, the convertible senior notes are convertible, in whole or in part, at the option of the noteholders at any time during the second quarter of 2026, and were classified as short-term debt, net of issuances costs, at March 31, 2026.

In May 2026, the Company made a voluntary principal prepayment of $100 million on its USD term loan B.

Second Quarter 2026 Guidance

•

Revenue of $1,200 million, plus or minus $40 million

•

Gross margin of 47.0%, plus or minus 1.0%

•

GAAP operating expenses of $337 million, plus or minus $5 million and Non-GAAP operating expenses of $275 million, plus or minus $5 million

•

GAAP net income of $151 million, plus or minus $21 million and Non-GAAP net earnings of $202 million, plus or minus $21 million

•

GAAP net income per diluted share of $2.09, plus or minus $0.29 and Non-GAAP net earnings per diluted share of $2.90, plus or minus $0.30

•

Adjusted EBITDA of $328 million, plus or minus $26 million

The guidance for the second quarter is based on the current business environment, including the impact of U.S. import tariffs and the imposition of retaliatory actions taken by other countries up through but not including the date of this release. The Company will continue to monitor and adapt to changes in the business environment as needed.

Conference Call Details

A conference call with management will be held on Thursday, May 7, 2026 at 8:30 a.m. (Eastern Time). To participate in the call by phone, participants should visit the Investor Relations section of MKS’ website at investor.mks.com and click on Events & Presentations, where you will be able to register online and receive dial-in details. We encourage participants to register and dial in to the conference call at least 15 minutes before the start of the call to ensure a timely connection. A live and archived webcast and related presentation materials will be available on the Investor Relations section of the MKS website.

About MKS Inc.

MKS Inc. (NASDAQ: MKSI) enables technologies that transform our world. We deliver foundational technology solutions to leading edge semiconductor manufacturing, electronics and packaging, and specialty industrial applications. We apply our broad science and engineering capabilities to create instruments, subsystems, systems, process control solutions and specialty chemicals technology that improve process performance, optimize productivity and enable unique innovations for many of the world's leading technology and industrial companies. Our solutions are critical to addressing the challenges of miniaturization and complexity in advanced device manufacturing by enabling increased power, speed, feature enhancement, and optimized connectivity. Our solutions are also critical to addressing ever-increasing performance requirements across a wide array of specialty industrial applications. Additional information can be found at www.mks.com.

Use of Non-GAAP Financial Results

This press release includes financial measures that are not in accordance with U.S. generally accepted accounting principles (“Non-GAAP financial measures”). These Non-GAAP financial measures should be viewed in addition to, and not as a substitute for, MKS’ reported results under U.S. generally accepted accounting principles (“GAAP”), and may be different from Non-GAAP financial measures used by other companies. In addition, these Non-GAAP financial measures are not based on any comprehensive set of accounting rules or principles. MKS management believes the presentation of these Non-GAAP financial measures is useful to investors for comparing prior periods and analyzing ongoing business trends and operating results. For further information regarding these Non-GAAP financial measures, please refer to the tables presenting reconciliations of our Non-GAAP results to our GAAP results and the “Notes on Our Non-GAAP Financial Information” at the end of this press release.

SAFE HARBOR FOR FORWARD-LOOKING STATEMENTS

This press release 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 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 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 level and terms of our substantial indebtedness and our ability to service such debt; risks related to pursuing, completing, and/or failing to realize the benefits of acquisitions and other strategic transactions critical to our growth strategy; risks related to cybersecurity, data privacy and intellectual property; manufacturing and sourcing risks, including supply chain disruptions, component shortages and price increases, the use of limited, sole source and international suppliers, the relocation of manufacturing operations, and product defects; risks associated with doing business internationally, including geopolitical conflicts, trade compliance, trade protection measures, such as import tariffs by the United States and/or retaliatory actions taken by other countries, regulatory restrictions on our products, components or markets, particularly the semiconductor market, and unfavorable currency exchange and tax rate fluctuations; conditions affecting the markets in which we operate, including intense competition, rapid technological and market changes, dependence on new product development, the ability to anticipate and meet customer demand, 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; risks associated with the attraction and retention of key personnel; potential fluctuations in quarterly results; volatility of stock price; risks associated with chemical manufacturing and environmental regulation compliance; risks associated with artificial intelligence (“AI”); financial and legal risk management; and the other important factors described under the heading “Risk Factors” in Part I, Item 1A of our Annual Report on Form 10-K for the year ended December 31, 2025 filed with the U.S. Securities and Exchange Commission and any subsequent Quarterly Reports on Form 10-Q. MKS is under no obligation to, and expressly disclaims 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, after the date of this press release. Amounts reported in this press release are preliminary and subject to finalization prior to the filing of our Quarterly Report on Form 10-Q for the quarter ended March 31, 2026.

Company Contact:

Paretosh Misra

Vice President, Investor Relations

Telephone: (978) 284-4705

Email: paretosh.misra@mks.com

MKS Inc.

Unaudited Consolidated Statements of Operations

(In millions, except per share data)


	Three Months Ended
	March 31,			December 31,			March 31,
	2026			2025			2025
Net revenues:
Products	$	954		$	907		$	819
Services		124			126			117
Total net revenues		1,078			1,033			936
Cost of revenues:
Products		514			491			437
Services		57			62			55
Total cost of revenues (exclusive of amortization shown separately below)		571			553			492
Gross profit		507			480			444
Research and development		81			78			70
Selling, general and administrative		190			185			185
Restructuring and other		3			11			16
Legal settlement		3			—			—
Fees and expenses related to debt activities		18			—			2
Amortization of intangible assets		63			62			60
Income from operations		149			144			111
Interest income		(2	)		(3	)		(3	)
Interest expense		45			50			53
Loss on extinguishment of debt		5			2			3
Other (income) expense, net		(1	)		6			(1	)
Income before income taxes		102			89			59
Provision (benefit) for income taxes		18			(19	)		7
Net income	$	84		$	108		$	52
Net income per share:
Basic	$	1.24		$	1.60		$	0.77
Diluted	$	1.18		$	1.58		$	0.77
Cash dividends per common share	$	0.25		$	0.22		$	0.22
Weighted average common shares outstanding:
Basic		67.4			67.3			67.4
Diluted		71.1			68.0			67.7

MKS Inc.

Unaudited Consolidated Balance Sheets

(In millions)


	March 31,			December 31,
	2026			2025
ASSETS
Cash and cash equivalents	$	569		$	675
Trade accounts receivable, net		775			651
Inventories		949			921
Other current assets		252			263
Total current assets		2,545			2,510
Property, plant and equipment, net		795			810
Right-of-use assets		267			270
Goodwill		2,565			2,574
Intangible assets, net		2,065			2,140
Other assets		491			492
Total assets	$	8,728		$	8,796
LIABILITIES AND STOCKHOLDERS' EQUITY
Short-term debt	$	1,398		$	51
Accounts payable		448			407
Other current liabilities		445			469
Total current liabilities		2,291			927
Long-term debt, net		2,650			4,150
Non-current deferred taxes		450			474
Non-current accrued compensation		146			149
Non-current lease liabilities		244			246
Other non-current liabilities		136			131
Total liabilities		5,917			6,077
Stockholders' equity:
Common stock		—			—
Additional paid-in capital		2,104			2,101
Retained earnings		778			711
Accumulated other comprehensive loss		(71	)		(93	)
Total stockholders' equity		2,811			2,719
Total liabilities and stockholders' equity	$	8,728		$	8,796

MKS Inc.

Unaudited Consolidated Statements of Cash Flows

(In millions)


	Three Months Ended
	March 31,			December 31,			March 31,
	2026			2025			2025
Cash flows from operating activities:
Net income	$	84		$	108		$	52
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization		85			86			85
Unrealized (gain) loss on foreign currency and derivative instruments		—			(6	)		2
Amortization of debt issuance costs and original issue discounts		4			6			6
Loss on extinguishment of debt		5			2			3
Stock-based compensation		19			8			22
Provision for excess and obsolete inventory		13			8			17
Deferred income taxes		(24	)		(71	)		(37	)
Other		1			2			1
Changes in operating assets and liabilities		(134	)		(1	)		(10	)
Net cash provided by operating activities		53			142			141
Cash flows from investing activities:
Net purchases of investments		—			1			—
Proceeds from sale of long-lived assets		—			1			—
Purchases of property, plant and equipment		(25	)		(51	)		(18	)
Net cash used in investing activities		(25	)		(49	)		(18	)
Cash flows from financing activities:
Repurchase of common stock		—			—			(45	)
Proceeds from borrowings		1,192			—			—
Payments of borrowings		(1,274	)		(113	)		(113	)
Payments of deferred financing fees		(22	)		—			—
Dividend payments		(17	)		(15	)		(15	)
Net (payments) proceeds related to employee stock awards		(16	)		3			(5	)
Other financing activities		—			—			(2	)
Net cash used in financing activities		(137	)		(125	)		(180	)
Effect of exchange rate changes on cash and cash equivalents		3			10			(2	)
Decrease in cash and cash equivalents		(106	)		(22	)		(59	)
Cash and cash equivalents at beginning of period		675			697			714
Cash and cash equivalents at end of period	$	569		$	675		$	655

The following supplemental Non-GAAP earnings information is presented to aid in understanding MKS’ operating results:

MKS Inc.

Schedule Reconciling Selected Non-GAAP Financial Measures

(In millions, except per share data)


	Three Months Ended
	March 31,			December 31,			March 31,
	2026			2025			2025
Net income	$	84		$	108		$	52
Restructuring and other		3			11			16
Legal settlement		3			—			—
Amortization of intangible assets		63			62			60
Loss on extinguishment of debt		5			2			3
Amortization of debt issuance costs		4			5			5
Loss from de-designation of interest rate hedges		2			—			—
Fees and expenses related to debt activities		18			—			2
Tax effect of Non-GAAP adjustments		(23	)		(20	)		(22	)
Non-GAAP net earnings	$	157		$	168		$	116
Non-GAAP net earnings per diluted share	$	2.30		$	2.47		$	1.71
Weighted average diluted shares outstanding		71.1			68.0			67.7
Convertible debt capped calls		2.9			—			—
Non-GAAP weighted average diluted shares outstanding		68.2			68.0			67.7
Net cash provided by operating activities	$	53		$	142		$	141
Purchases of property, plant and equipment		(25	)		(51	)		(18	)
Free cash flow	$	29		$	91		$	123
Operating expenses	$	358		$	336		$	332
Restructuring and other		3			11			16
Legal settlement		3			—			—
Amortization of intangible assets		63			62			60
Fees and expenses related to debt activities		18			—			2
Non-GAAP operating expenses	$	271		$	263		$	254
Income from operations	$	149		$	144		$	111
Operating margin		13.8	%		13.9	%		11.9	%
Restructuring and other		3			11			16
Legal settlement		3			—			—
Amortization of intangible assets		63			62			60
Fees and expenses related to debt activities		18			—			2
Non-GAAP income from operations	$	235		$	217		$	189
Non-GAAP operating margin		21.8	%		21.0	%		20.2	%
Interest expense, net	$	43		$	47		$	50
Amortization of debt issuance costs		4			5			5
Loss from de-designation of interest rate hedges		2			—			—
Non-GAAP interest expense, net	$	37		$	42		$	45
Net income	$	84		$	108		$	52
Interest expense, net		43			47			50
Other (income) expense, net		(1	)		6			(1	)
Provision (benefit) for income taxes		18			(19	)		7
Depreciation		22			24			25
Amortization of intangible assets		63			62			60
Stock-based compensation		19			8			22
Restructuring and other		3			11			16
Legal settlement		3			—			—
Loss on extinguishment of debt		5			2			3
Fees and expenses related to debt activities		18			—			2
Adjusted EBITDA	$	277		$	249		$	236
Adjusted EBITDA margin		25.7	%		24.1	%		25.2	%

MKS Inc.

Schedule Reconciling Selected Non-GAAP Financial Measures

(In millions, except per share data)


	Three Months Ended March 31, 2026					Three Months Ended December 31, 2025
	Income Before Income Taxes		Provision for Income Taxes		Effective Tax Rate	Income Before Income Taxes		(Benefit) Provision for Income Taxes			Effective Tax Rate
GAAP	$	102	$	18	17.7%	$	89	$	(19	)	(20.8%)
Restructuring and other		3		—			11		—
Legal settlement		3		—			—		—
Amortization of intangible assets		63		—			62		—
Loss on extinguishment of debt		5		—			2		—
Amortization of debt issuance costs		4		—			5		—
Loss from de-designation of interest rate hedges		2		—			—		—
Fees and expenses related to debt activities		18		—			—		—
Tax effect of Non-GAAP adjustments		—		23			—		20
Non-GAAP	$	198	$	41	20.9%	$	169	$	1		0.9%


	Three Months Ended March 31, 2025
	Income Before Income Taxes		Provision for Income Taxes		Effective Tax Rate
GAAP	$	59	$	7	12.3%
Restructuring and other		16		—
Amortization of intangible assets		60		—
Loss on extinguishment of debt		3		—
Amortization of debt issuance costs		5		—
Fees and expenses related to debt activities		2		—
Tax effect of Non-GAAP adjustments		—		22
Non-GAAP	$	145	$	29	19.9%

MKS Inc.

Schedule Reconciling Selected Non-GAAP Financial Measures - Q2’26 Guidance

(In millions, except per share data)


	Three Months Ending June 30, 2026
	$ Amount			Per Share
GAAP net income and net income per share	$	151		$	2.09
Restructuring and other		1
Amortization of intangible assets		61
Loss on extinguishment of debt		3
Amortization of debt issuance costs		3
Tax effect of Non-GAAP adjustments		(17	)
Non-GAAP net earnings and net earnings per share	$	202		$	2.90

Weighted average diluted shares		72.3
Convertible debt capped calls		(2.7	)
Non-GAAP weighted average diluted shares		69.6

GAAP operating expenses	$	337
Restructuring and other		(1	)
Amortization of intangible assets		(61	)
Non-GAAP operating expenses	$	275

GAAP net income		151
Interest expense, net		38
Provision for income taxes		35
Depreciation		24
Restructuring and other		1
Amortization of intangible assets		61
Stock-based compensation		15
Loss on extinguishment of debt		3
Adjusted EBITDA	$	328


	EXHIBIT 99.1