赛默飞世尔科技美股招股说明书(2026-02-10版)

We are offering $1,000,000,000 aggregate principal amount of 4.215% Senior Notes due 2031 (the “2031 notes”), $750,000,000aggregate principal amount of 4.550% Senior Notes due 2033 (the “2033 notes”), $1,300,000,000 aggregate principal amount of4.902% Senior Notes due 2036 (the “2036 notes”) and $750,000,000 aggregate principal amount of 5.546% Senior Notes due 2046 (the“2046 notes” and, collectively with the 2031 notes, the 2033 notes and the 2036 notes, the “notes”). We will pay interest on the 2031notes, the 2036 notes and the 2046 notes semi-annually in arrears on February12 and August12 of each year, beginning on August12,2026. We will pay interest on the 2033 notes semi-annually in arrears on June 15 and December 15 of each year, beginning on June 15,2026. The 2031 notes will mature on February12, 2031, the 2033 notes will mature on June15, 2033, the 2036 notes will mature onFebruary12, 2036 and the 2046 notes will mature on February12, 2046. We may redeem some or all of the notes at any time and from time to time at the applicable redemption prices described in thisprospectus supplement. See “Description of the Notes—Optional Redemption.” If a Change of Control Triggering Event as described inthis prospectus supplement occurs with respect to any series of notes, we may be required to offer to purchase the notes of such seriesfrom the holders. See “Description of the Notes—Repurchase Upon a Change of Control.” The notes will not be entitled to the benefitof any sinking fund. The notes will be our general unsecured obligations and will rank equally in right of payment with all of our other existing and futureunsecured senior indebtedness and will rank senior to any subordinated indebtedness that we may incur. Investing in the notes involves risks. See “Risk Factors” beginning on page S-7and PartI, Item1A. “RiskFactors” of ourAnnual Report on Form10-K for the fiscal year ended December31, 2024, filed with the Securities and Exchange Commission(“SEC”) on February20, 2025 (our “2024 Form10-K”), which is incorporated by reference herein, before deciding to invest inthe notes. Interest on the notes will accrue from February12, 2026. Neither the SEC nor any state securities commission has approved or disapproved of these securities or determined if thisprospectus supplement or the accompanying prospectus is truthful or complete. Any representation to the contrary is a criminaloffense. The notes will be ready for delivery in book-entry form only through the facilities of The Depository Trust Company (“DTC”) for theaccounts of its participants, including Euroclear Bank SA/NV, as operator of the Euroclear System (“Euroclear”), and ClearstreamBanking S.A. (“Clearstream”), on or about February12, 2026. TABLE OF CONTENTSProspectus Supplement PageABOUT THIS PROSPECTUS SUPPLEMENTS-iiSPECIAL NOTE ABOUT FORWARD-LOOKING STATEMENTSS-iiiSUMMARYS-1RISK FACTORSS-7USE OF PROCEEDSS-10DESCRIPTION OF THE NOTESS-11MATERIAL U.S. FEDERAL TAX CONSIDERATIONSS-20UNDERWRITINGS-24LEGAL MATTERSS-30EXPERTSS-30WHERE YOU CAN FIND MORE INFORMATION AND INCORPORATION BY REFERENCES-31 TABLE OF CONTENTS ABOUT THIS PROSPECTUS SUPPLEMENT This document consists of two parts. The first part is the prospectus supplement, which describes the specific termsof this offering. The second part is the prospectus, which describes more general information, some of which maynot apply to this offering. Generally, when we refer to this prospectus, we are referring to both parts of thisdocument combined. To the extent there is a conflict between the information contained in this prospectussupplement and the information contained in the accompanying prospectus or any document incorporated byreference therein filed prior to the date of this prospectus supplement, you should rely on the information in thisprospectus supplement; provided that if any statement in one of these documents is inconsistent with a statement inanother document having a later date—for example, a document incorporated by reference in the accompanyingprospectus—the statement in the document having the later date modifies or supersedes the earlier statement. Youshould read this prospectus supplement, any related free writing prospectus that we provide to you and theaccompanying prospectus, together with the additional information described under the heading “Where You CanFind More Information and Incorporation by Reference” elsewhere in this prospectus supplement. In this prospectus supplement, except as otherwise indicated or unless the context otherwise requires, “ThermoFisher,” “the company,” “we,” “us” and “our” refer to Thermo Fisher Scientific Inc. and its consolidatedsubsidiaries. If the information set forth in this prospectus supplement differs in any way from the information setforth in the accompanying prospectus, you should rely on the information set forth in this prospectus supplement. References in this prospectus supplement to “U.S. dollars,” “U.S. $” or “$” are to