UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 OR 15(d) of

~~The~~the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported) ~~July~~ ~~29,~~September ~~2025 (July 25~~9, 2025)

Merck & Co., Inc.

(Exact name of registrant as specified in its charter)

New Jersey (State or other jurisdiction of incorporation) 1-6571 (Commission File Number) 22-1918501 (I.R.S. Employer Identification No.)


New Jersey	1-6571	22-1918501
(State or other jurisdiction	(Commission	(I.R.S Employer
of incorporation)	File Number)	Identification No.)

126 East Lincoln Avenue, Rahway, NJ (Address of principal executive offices) 07065 (Zip Code)


126 East Lincoln Avenue, Rahway, New Jersey			07065
(Address of principal executive offices)			(Zip Code)

(Registrant’s telephone number, including area code) (~~732~~908) ~~594~~740-4000

Not Applicable

(Former name or former address, if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

¨☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ¨ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ¨ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ¨ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

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

Title of each class

Trading Symbol(s)

Name of each exchange on which registered

Common Stock ($0.50 par value)

MRK

New York Stock Exchange

1.875% Notes due 2026

MRK/26

New York Stock Exchange

3.250% Notes due 2032

MRK/32

New York Stock Exchange

2.500% Notes due 2034

MRK/34

New York Stock Exchange

1.375% Notes due 2036

MRK 36A

New York Stock Exchange

3.500% Notes due 2037

MRK/37

New York Stock Exchange

3.700% Notes due 2044

MRK/44

New York Stock Exchange

3.750% Notes due 2054

MRK/54

New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ¨ ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨ ☐

Item 28.~~02.~~01 ~~Results~~Other ~~of Operations and Financial Condition~~Events.

~~The~~On ~~following~~September ~~information~~9, ~~including~~2025, Merck & Co., Inc. (the ~~exhibits~~“Company”) ~~hereto~~closed an underwritten public offering of $500, is000,000 ~~being~~aggregate ~~furnished~~principal ~~pursuant~~amount toof ~~this~~Floating ~~Item~~Rate 2Notes due 2027 (the “Floating Rate Notes”), $750,000,000 aggregate principal amount of 3.02850% Notes due 2027 (the “2027 Notes”), $750,000,000 aggregate principal amount of 4.150% Notes due 2030 (the “2030 Notes”), $1,000,000,000 aggregate principal amount of 4.550% Notes due 2032 (the “2032 Notes”), $1,750,000,000 aggregate principal amount of 4.950% Notes due 2035 (the “2035 Notes”) and $1,250,000,000 aggregate principal amount of 5.700% Notes due 2055 (the “2055 Notes” and, together with the Floating Rate Notes, the 2027 Notes, the 2030 Notes, the 2032 Notes and the 2035 Notes, collectively, the “Notes”) under the Company’s Registration Statement on Form S-3ASR (Registration No. 333-278066), originally filed with the Securities and Exchange Commission (the “Commission”) on March 19, 2024, as amended by Post-Effective Amendment No. 1, filed with the Commission on May 14, 2024.

~~Incorporated~~The byNotes ~~reference~~are isbeing ~~a press~~issued ~~release~~under ~~issued~~an byindenture ~~Merck~~dated &as Coof January 6, 2010, between the Company and U.S. Bank Trust National Association, ~~Inc~~as trustee, a copy of which was attached as Exhibit 4.1 to the Company’s Current Report on ~~July~~Form 8-K ~~29,~~previously ~~2025~~filed with the Securities and Exchange Commission on December 10, ~~regarding~~2010 ~~earnings~~and is incorporated herein by reference. Copies of the officers’ certificate for each series of the ~~second~~Notes ~~quarter~~(including forms of ~~2025,~~each of the respective Notes attached thereto) pursuant to Section 301 of the indenture governing the Notes are attached hereto as ~~Exhibit 99~~Exhibits 4.1, 4.2, ~~Also~~4.3, 4.4, 4.5 and 4.6 and are incorporated herein by reference. isThe ~~certain~~legal ~~supplemental~~opinion ~~information~~related ~~not~~to ~~included~~these inNotes ~~the~~is ~~press release,~~ attached hereto as Exhibit 995.21 and is incorporated herein by reference.

~~This~~Item ~~information~~9.01 ~~shall~~Financial ~~not~~Statements ~~be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that Section,~~ and ~~is not incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such filing~~Exhibits.

~~Item~~(d) ~~2.05. Costs Associated with Exit or Disposal Activities.~~Exhibits

On July 25, 2025, the Company approved a new restructuring program (2025 Restructuring Program) designed to position the Company for its next chapter of growth and to successfully advance its pipeline and launch new products across multiple therapeutic areas. As part of this program, the Company expects to eliminate certain positions in sales and administrative organizations, as well as research and development. The Company will, however, continue to hire employees into new roles across all strategic growth areas of the business. In addition, the Company will reduce its global real estate footprint and continue to optimize its manufacturing network, aligning the geography of its global manufacturing footprint to its customers and reflecting changes in the Company’s business.


Exhibit 4.1						Floating Rate Notes due 2027 Officers’ Certificate of the Company dated September 9, 2025, including form of the Floating Rate Notes.
Exhibit 4.2						3.850% Notes due 2027 Officers’ Certificate of the Company dated September 9, 2025, including form of the 2027 Notes.
Exhibit 4.3						4.150% Notes due 2030 Officers’ Certificate of the Company dated September 9, 2025, including form of the 2030 Notes.
Exhibit 4.4						4.550% Notes due 2032 Officers’ Certificate of the Company dated September 9, 2025, including form of the 2032 Notes.
Exhibit 4.5						4.950% Notes due 2035 Officers’ Certificate of the Company dated September 9, 2025, including form of the 2035 Notes.
Exhibit 4.6						5.700% Notes due 2055 Officers’ Certificate of the Company dated September 9, 2025, including form of the 2055 Notes.
Exhibit 5.1						Opinion and Consent of Jennifer Zachary, Esq., Executive Vice President and General Counsel of the Company.
Exhibit 23.1						Consent of Jennifer Zachary, Esq., Executive Vice President and General Counsel of the Company (contained in Exhibit 5.1 to this Current Report on Form 8-K).
Exhibit 104						Cover Page Interactive Data File (embedded within the Inline XBRL document).

~~Most~~SIGNATURES actions contemplated under the 2025 Restructuring Program are expected to be largely completed by the end of 2027, with the exception of certain manufacturing actions, which are expected to be substantially completed by the end of 2029. The cumulative pretax costs to be incurred by the Company to implement the program are estimated to be approximately $3.0 billion, of which approximately 60% will be cash, relating primarily to employee separation expense and contractual termination costs. The remainder of the costs will be non-cash, relating primarily to the accelerated depreciation of facilities. The Company expects the actions under the 2025 Restructuring Program to result in annual cost savings of approximately $1.7 billion, which will be substantially realized by the end of 2027. The 2025 Restructuring Program is part of the Company’s multiyear optimization initiative anticipated to achieve $3.0 billion in annual cost savings by the end of 2027, which will be fully reinvested into strategic growth areas of the business.

~~Item~~Pursuant ~~9.01.~~to ~~Financial~~the ~~Statements~~requirements ~~and~~of ~~Exhibits~~the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	(d) Exhibits
			Merck & Co., Inc.
	Exhibit 99.1	Press release issued July 29, 2025, regarding earnings for the second quarter of 2025
Date: September 9, 2025			By:	/s/ Kelly E. W. Grez
	Exhibit 99.2	Certain supplemental information not included in the press release
				Kelly E. W. Grez
	Exhibit 104	Cover Page Interactive Data File (embedded within the Inline XBRL document)
				Corporate Secretary

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

		Merck & Co., Inc.
Date: July 29, 2025	By:	/s/ Kelly E. W. Grez
		Kelly E. W. Grez Corporate Secretary

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