Cover and table of contents

UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

☒ Annual Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the fiscal year ended December 31, 2025 or

☐ Transition Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Commission file number 1-8002

THERMO FISHER SCIENTIFIC INC.

(Exact name of Registrant as specified in its charter)

168 Third Avenue

Waltham, Massachusetts 02451

(Address of principal executive offices) (Zip Code)

Registrant’s telephone number, including area code: (781) 622-1000

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ☒ No ☐

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Act. Yes ☐ No ☒

Indicate by check mark whether the Registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No ☐

Indicate by check mark whether the Registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months. Yes ☒ No ☐

Indicate by check mark whether the Registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act. Large accelerated filer ☒ Accelerated filer ☐ Non-accelerated filer ☐ Smaller reporting company ☐ Emerging growth company ☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☒

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. ☐

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to § 240.10D-1(b). ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ☐ No ☒

As of June 27, 2025, the aggregate market value of the voting stock held by nonaffiliates of the Registrant was approximately $154,038,987,000 (based on the last reported sale of common stock on the New York Stock Exchange Composite Tape reporting system on June 27, 2025).

As of January 31, 2026, the Registrant had 371,484,244 shares of Common Stock outstanding.

DOCUMENTS INCORPORATED BY REFERENCE

Sections of Thermo Fisher’s definitive Proxy Statement for the 2026 Annual Meeting of Shareholders (the “Proxy Statement”) are incorporated by reference into Part III of this report.

THERMO FISHER SCIENTIFIC INC.

ANNUAL REPORT ON FORM 10-K

FOR THE FISCAL YEAR ENDED DECEMBER 31, 2025

TABLE OF CONTENTS

THERMO FISHER SCIENTIFIC INC.

PART I

Forward-looking Statements

This Annual Report on Form 10-K (this Annual Report) and our 2025 Annual Report to Shareholders contain “forward-looking statements”, within the meaning of the Private Securities Litigation Reform Act of 1995 and other applicable securities laws. Forward-looking statements are based on current expectations and assumptions that are subject to risks and uncertainties, and are often identified by words such as “expects,” “anticipates,” “intends,” “plans,” “believes,” “seeks,” “estimates,” “may,” “will,” “should,” or similar expressions or words with similar meanings. Any statements contained herein that are not statements of historical fact should be considered forward-looking statements.

Forward-looking statements in this Annual Report and our 2025 Annual Report to Shareholders include, among others, statements regarding:

• financial expectations**, including projections of revenues, expenses, margins, earnings, cash flows, liquidity, capital allocation plans, and tax matters;

• operational matters**, including business strategies, productivity initiatives, restructuring activities, cost-reduction programs, and new product or service developments;

• market and competitive conditions**, including customer demand trends, industry dynamics, pricing, and competitive positioning;

• strategic actions**, including planned acquisitions, divestitures, investments, and partnerships;

• legal, regulatory, macroeconomic, geopolitical, public health, supply chain, technology, and cybersecurity developments** and their potential impacts on the company; and

• the timing and outcomes of any of the foregoing.

Each forward-looking statement contained in this Annual Report and our 2025 Annual Report to Shareholders is inherently uncertain and involves significant risks, assumptions, and factors that could cause actual results to differ materially from those expressed or implied. Important risks and uncertainties that could cause such differences are detailed under the heading, “Risk Factors” in Part I, Item 1A.

Forward-looking statements in this Annual Report and our 2025 Annual Report to Shareholders speak only as of the dates on which they are made. While the company may elect to update forward-looking statements in the future, it specifically disclaims any obligation to do so, in the event of new information, future developments, or otherwise, except as required by law.