Merck & Co. (MRK) 10-Q 5 Aug 24 2024 Q2 Quarterly report Financial data

Cover Page

Cover Page - shares	6 Months Ended
	Jun. 30, 2024	Jul. 31, 2024
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2024
Document Transition Report	false
Entity File Number	1-6571
Entity Registrant Name	Merck & Co., Inc.
Entity Incorporation, State or Country Code	NJ
Entity Tax Identification Number	22-1918501
Entity Address, Address Line One	126 East Lincoln Avenue
Entity Address, City or Town	Rahway
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	07065
City Area Code	(908)
Local Phone Number	740-4000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		2,534,809,312
Amendment Flag	false
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q2
Entity Central Index Key	0000310158
Current Fiscal Year End Date	--12-31
Common Stock ($0.50 par value)
Entity Information [Line Items]
Title of 12(b) Security	Common Stock ($0.50 par value)
Trading Symbol	MRK
Security Exchange Name	NYSE
0.500% Notes due 2024
Entity Information [Line Items]
Title of 12(b) Security	0.500% Notes due 2024
Trading Symbol	MRK 24
Security Exchange Name	NYSE
1.875% Notes due 2026
Entity Information [Line Items]
Title of 12(b) Security	1.875% Notes due 2026
Trading Symbol	MRK/26
Security Exchange Name	NYSE
3.250% Notes due 2032
Entity Information [Line Items]
Title of 12(b) Security	3.250% Notes due 2032
Trading Symbol	MRK/32
Security Exchange Name	NYSE
2.500% Notes due 2034
Entity Information [Line Items]
Title of 12(b) Security	2.500% Notes due 2034
Trading Symbol	MRK/34
Security Exchange Name	NYSE
1.375% Notes due 2036
Entity Information [Line Items]
Title of 12(b) Security	1.375% Notes due 2036
Trading Symbol	MRK 36A
Security Exchange Name	NYSE
3.500% Notes due 2037
Entity Information [Line Items]
Title of 12(b) Security	3.500% Notes due 2037
Trading Symbol	MRK/37
Security Exchange Name	NYSE
3.700% Notes due 2044
Entity Information [Line Items]
Title of 12(b) Security	3.700% Notes due 2044
Trading Symbol	MRK/44
Security Exchange Name	NYSE
3.750% Notes due 2054
Entity Information [Line Items]
Title of 12(b) Security	3.750% Notes due 2054
Trading Symbol	MRK/54
Security Exchange Name	NYSE

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENT OF OPERATIONS - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Income Statement [Abstract]
Sales	$ 16,112	$ 15,035	$ 31,887	$ 29,522
Costs, Expenses and Other
Cost of sales	3,745	4,024	7,285	7,951
Selling, general and administrative	2,739	2,702	5,221	5,182
Research and development	3,500	13,321	7,492	17,597
Restructuring costs	80	151	202	218
Other (income) expense, net	42	172	12	259
Total Costs, Expenses and Other	10,106	20,370	20,212	31,207
Income (Loss) Before Taxes	6,006	(5,335)	11,675	(1,685)
Income Tax Provision	545	637	1,447	1,462
Net Income (Loss)	5,461	(5,972)	10,228	(3,147)
Less: Net Income Attributable to Noncontrolling Interests	6	3	11	7
Net Income (Loss) Attributable to Merck & Co., Inc.	$ 5,455	$ (5,975)	$ 10,217	$ (3,154)
Basic Earnings (Loss) per Common Share Attributable to Merck & Co., Inc. Common Shareholders (in dollars per share)	$ 2.15	$ (2.35)	$ 4.03	$ (1.24)
Earnings (Loss) per Common Share Assuming Dilution Attributable to Merck & Co., Inc. Common Shareholders (in dollars per share)	$ 2.14	$ (2.35)	$ 4.02	$ (1.24)

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Statement of Comprehensive Income [Abstract]
Net Income (Loss) Attributable to Merck & Co., Inc.	$ 5,455	$ (5,975)	$ 10,217	$ (3,154)
Other Comprehensive Loss Net of Taxes:
Net unrealized gain on derivatives, net of reclassifications	67	145	197	12
Benefit plan net (loss) gain and prior service (cost) credit, net of amortization	(10)	(25)	(15)	(75)
Cumulative translation adjustment	(144)	(137)	(382)	(69)
Other comprehensive income (loss), net of taxes	(87)	(17)	(200)	(132)
Comprehensive Income (Loss) Attributable to Merck & Co., Inc.	$ 5,368	$ (5,992)	$ 10,017	$ (3,286)

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEET - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Current Assets
Cash and cash equivalents	$ 11,304	$ 6,841
Short-term investments	50	252
Accounts receivable (net of allowance for doubtful accounts of $82 in 2024 and $88 in 2023)	11,642	10,349
Inventories (excludes inventories of $3,456 in 2024 and $3,348 in 2023 classified in Other assets - see Note 6)	6,469	6,358
Other current assets	8,740	8,368
Total current assets	38,205	32,168
Investments	357	252
Property, Plant and Equipment, at cost, net of accumulated depreciation of $18,960 in 2024 and $18,266 in 2023	23,221	23,051
Goodwill	21,161	21,197
Other Intangibles, Net	16,984	18,011
Other Assets	12,702	11,996
Total Assets	112,630	106,675
Current Liabilities
Loans payable and current portion of long-term debt	3,071	1,372
Trade accounts payable	3,519	3,922
Accrued and other current liabilities	14,712	15,766
Income taxes payable	2,777	2,649
Dividends payable	1,981	1,985
Total current liabilities	26,060	25,694
Long-Term Debt	34,717	33,683
Deferred Income Taxes	876	871
Other Noncurrent Liabilities	7,329	8,792
Merck & Co., Inc. Stockholders’ Equity
Common stock, $0.50 par value Authorized - 6,500,000,000 shares Issued - 3,577,103,522 shares in 2024 and 2023	1,788	1,788
Other paid-in capital	44,362	44,509
Retained earnings	60,187	53,895
Accumulated other comprehensive loss	(5,361)	(5,161)
Stockholders' equity before deduction for treasury stock	100,976	95,031
Less treasury stock, at cost: 1,041,454,052 shares in 2024 and 1,045,470,249 shares in 2023	57,394	57,450
Total Merck & Co., Inc. stockholders’ equity	43,582	37,581
Noncontrolling Interests	66	54
Total equity	43,648	37,635
Liabilities and Equity	$ 112,630	$ 106,675

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEET (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 82	$ 88
Inventories classified in Other assets	3,456	3,348
Accumulated depreciation	$ 18,960	$ 18,266
Common stock, par value (in dollars per share)	$ 0.50	$ 0.50
Common stock, authorized (shares)	6,500,000,000	6,500,000,000
Common stock, issued (in shares)	3,577,103,522	3,577,103,522
Treasury stock (in shares)	1,041,454,052	1,045,470,249

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENT OF CASH FLOWS - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Cash Flows from Operating Activities
Net income (loss)	$ 10,228	$ (3,147)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Amortization	1,087	1,020
Depreciation	1,029	874
Income from investments in equity securities, net	(200)	(274)
Charge for the acquisition of Harpoon Therapeutics, Inc.	656	0
Charge for the acquisition of Prometheus Biosciences, Inc.	0	10,217
Charge for the acquisition of Imago BioSciences, Inc.	0	1,192
Deferred income taxes	(232)	(632)
Share-based compensation	379	314
Other	174	5
Net changes in assets and liabilities	(4,394)	(4,526)
Net Cash Provided by Operating Activities	8,727	5,043
Cash Flows from Investing Activities
Capital expenditures	(1,652)	(1,972)
Purchases of securities and other investments	(64)	(587)
Proceeds from sales of securities and other investments	320	785
Acquisition of Harpoon Therapeutics, Inc., net of cash acquired	(746)	0
Acquisition of Prometheus Biosciences, Inc., net of cash acquired	0	(10,705)
Acquisition of Imago BioSciences, Inc., net of cash acquired	0	(1,327)
Other	(303)	4
Net Cash Used in Investing Activities	(2,445)	(13,802)
Cash Flows from Financing Activities
Net change in short-term borrowings	0	1,937
Proceeds from issuance of debt	3,600	5,946
Payments on debt	(751)	(1,751)
Dividends paid to stockholders	(3,936)	(3,738)
Purchases of treasury stock	(373)	(487)
Proceeds from exercise of stock options	160	112
Other	(298)	(315)
Net Cash (Used in) Provided by Financing Activities	(1,598)	1,704
Effect of Exchange Rate Changes on Cash, Cash Equivalents and Restricted Cash	(220)	(6)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	4,464	(7,061)
Cash, Cash Equivalents and Restricted Cash at Beginning of Year (includes restricted cash of $68 and $79 at January 1, 2024 and 2023, respectively, included in Other current assets)	6,909	12,773
Cash, Cash Equivalents and Restricted Cash at End of Period (includes restricted cash of $69 and $52 at June 30, 2024 and 2023, respectively, included in Other current assets)	$ 11,373	$ 5,712

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENT OF CASH FLOWS (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023	Jun. 30, 2023	Dec. 31, 2022
Statement of Cash Flows [Abstract]
Restricted cash	$ 69	$ 68	$ 52	$ 79

Basis of Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements of Merck & Co., Inc. (Merck or the Company) have been prepared pursuant to the rules and regulations for reporting on Form 10-Q. Accordingly, certain information and disclosures required by accounting principles generally accepted in the United States (U.S.) for complete consolidated financial statements are not included herein. These interim statements should be read in conjunction with the audited financial statements and notes thereto included in Merck’s Form 10-K filed on February 26, 2024. The results of operations of any interim period are not necessarily indicative of the results of operations for the full year. In the Company’s opinion, all adjustments necessary for a fair statement of these interim statements have been included and are of a normal and recurring nature. Certain reclassifications have been made to prior year amounts to conform to the current year presentation. Recently Adopted Accounting Standard In August 2023, the Financial Accounting Standards Board (FASB) issued amended guidance that requires a newly formed joint venture to recognize and initially measure its assets and liabilities at fair value upon formation. The amended guidance includes exceptions to fair value measurement that are consistent with the accounting for business combinations guidance. The amended guidance is effective prospectively for all joint ventures with a formation date on or after January 1, 2025, however existing joint ventures have the option to apply the guidance retrospectively. The Company adopted the guidance effective July 1, 2024 on a prospective basis. There was no impact to the Company’s consolidated financial statements upon adoption. Recently Issued Accounting Standards Not Yet Adopted In November 2023, the FASB issued guidance intended to improve reportable segment disclosure requirements, primarily through expanded disclosures for significant segment expenses. The guidance is effective for annual periods beginning in 2024, and interim periods beginning in 2025. The guidance will result in incremental disclosures within the footnotes to the Company’s financial statements.

Acquisitions, Divestitures, Res

Acquisitions, Divestitures, Research Collaborations and Licensing Agreements	6 Months Ended
	Jun. 30, 2024
Business Combination, Asset Acquisition, and Joint Venture Formation [Abstract]
Acquisitions, Divestitures, Research Collaborations and Licensing Agreements	Acquisitions, Divestitures, Research Collaborations and Licensing Agreements The Company continues to pursue acquisitions and the establishment of external alliances such as research collaborations and licensing agreements to complement its internal research capabilities. These arrangements often include upfront payments; expense reimbursements or payments to the third party; milestone, royalty or profit share arrangements contingent upon the occurrence of certain future events linked to the success of the asset in development; and can also include option and continuation payments. The Company also reviews its marketed products and pipeline to examine candidates which may provide more value through out-licensing and, as part of its portfolio assessment process, may also divest certain assets. Pro forma financial information for acquired businesses is not presented if the historical financial results of the acquired entity are not significant when compared with the Company’s financial results. 2024 Transactions In July 2024, Merck acquired the aqua business of Elanco Animal Health Incorporated (Elanco) for approximately $1.3 billion. The Elanco aqua business consists of an innovative portfolio of medicines and vaccines, nutritionals and supplements for aquatic species; two related aqua manufacturing facilities in Canada and Vietnam; as well as a research facility in Chile. The acquisition broadens Animal Health’s aqua portfolio with products such as Clynav, a new generation DNA-based vaccine that protects Atlantic salmon against pancreas disease, and Imvixa, an anti-parasitic sea lice treatment. This acquisition also brings a portfolio of water treatment products for warm water production, complementing Animal Health’s warm water vaccine portfolio. In addition to these products, the DNA-based vaccine technology that is a part of the business has the potential to accelerate the development of novel vaccines to address the unmet needs of the aqua industry. The Company is in the process of determining the preliminary fair value of assets acquired, liabilities assumed and total consideration transferred in this transaction, which will be accounted for as a business combination. Also in July 2024, Merck acquired Eyebiotech Limited (EyeBio), a privately held ophthalmology-focused biotechnology company for an upfront payment of $1.3 billion. The acquisition agreement also provides for a further $1.7 billion in potential developmental, regulatory and sales-based milestone payments. EyeBio’s development work focused on candidates for the prevention and treatment of vision loss associated with retinal vascular leakage, a known risk factor for retinal diseases. EyeBio’s lead candidate, Restoret /MK-3000 (formerly EYE103), is an investigational, potentially first-in-class tetravalent, tri-specific antibody that acts as an agonist of the Wingless-related integration site signaling pathway, which is in clinical development for the treatment of diabetic macular edema and neovascular age-related macular degeneration. The transaction will be accounted for as an asset acquisition since Restoret/ MK-3000 accounted for substantially all of the fair value of the gross assets acquired (excluding cash and deferred income taxes). Merck will record a charge of approximately $1.3 billion to Research and development expenses in the third quarter of 2024. Additionally in July 2024, Merck and Orion Corporation (Orion) announced the mutual exercise of an option to convert the companies’ ongoing co-development and co-commercialization agreement for opevesostat (MK-5684/ODM-208), an investigational cytochrome P450 11A1 (CYP11A1) inhibitor, and other candidates targeting CYP11A1, into an exclusive global license for Merck. With the exercise of the option, Merck will assume full responsibility for all past and future development and commercialization expenses associated with the candidates covered by the original agreement. In addition, Orion will become eligible to receive developmental milestone payments up to $30 million, regulatory milestone payments up to $625 million and sales-based milestone payments up to $975 million, as well as annually tiered royalty payments ranging from a low double-digit rate up to a rate in the low twenties on net sales for any commercialized licensed product. Orion will retain responsibility for the manufacture of clinical and commercial supply for Merck. No payment was associated with the exercise of the option. The exclusive global license is expected to become effective in the third quarter of 2024, but is subject to certain conditions, including approval under the Hart-Scott-Rodino Antitrust Improvements Act, and other customary conditions. In March 2024, Merck acquired Harpoon Therapeutics, Inc. (Harpoon), a clinical-stage immunotherapy company developing a novel class of T-cell engagers designed to harness the power of the body’s immune system to treat patients suffering from cancer and other diseases, for $765 million and also incurred $56 million of transaction costs. Harpoon’s lead candidate, MK-6070 (formerly HPN328), is a T-cell engager targeting delta-like ligand 3 (DLL3), an inhibitory canonical Notch ligand that is expressed at high levels in small-cell lung cancer (SCLC) and neuroendocrine tumors. MK-6070 is currently being evaluated as monotherapy in a Phase 1/2 clinical trial in certain patients with advanced cancers associated with expression of DLL3. The study is also evaluating MK-6070 in combination with atezolizumab in certain patients with SCLC. The transaction was accounted for as an asset acquisition since MK-6070 represented substantially all of the fair value of the gross assets acquired (excluding cash and deferred income taxes). Merck recorded net assets of $165 million, as well as a charge of $656 million to Research and development expenses in the first six months of 2024 related to the transaction. There are no future contingent payments associated with the acquisition. 2023 Transactions In June 2023, Merck acquired Prometheus Biosciences, Inc. (Prometheus), a clinical-stage biotechnology company pioneering a precision medicine approach for the discovery, development, and commercialization of novel therapeutic and companion diagnostic products for the treatment of immune-mediated diseases. Total consideration paid of $11.0 billion included $1.2 billion of costs to settle share-based equity awards (including $700 million to settle unvested equity awards). Prometheus’ lead candidate, tulisokibart (MK-7240, formerly PRA023), is a humanized monoclonal antibody directed to tumor necrosis factor-like ligand 1A, a target associated with both intestinal inflammation and fibrosis. Tulisokibart is being developed for the treatment of immune-mediated diseases including ulcerative colitis, Crohn’s disease, and other autoimmune conditions. A Phase 3 clinical trial evaluating tulisokibart for ulcerative colitis commenced in 2023. The transaction was accounted for as an acquisition of an asset since tulisokibart accounted for substantially all of the fair value of the gross assets acquired (excluding cash and deferred income taxes). Merck recorded net assets of $877 million, including cash of $368 million, investments of $296 million, deferred tax assets of $218 million and other net liabilities of $5 million, as well as a charge of $10.2 billion to Research and development expenses in the second quarter and first six months of 2023 related to the transaction. There are no future contingent payments associated with the acquisition. In February 2023, Merck and Kelun-Biotech (a holding subsidiary of Sichuan Kelun Pharmaceutical Co., Ltd.) closed a license and collaboration agreement expanding their relationship in which Merck gained exclusive rights for the research, development, manufacture and commercialization of up to seven investigational preclinical antibody drug conjugates (ADCs) for the treatment of cancer. Kelun-Biotech retained the right to research, develop, manufacture and commercialize certain licensed and option ADCs for Chinese mainland, Hong Kong and Macau. Merck made an upfront payment of $175 million, which was recorded as a charge to Research and development expenses in the first six months of 2023. In October 2023, Merck notified Kelun-Biotech it was terminating two of the seven candidates under the agreement. Subsequently, in April 2024, Merck notified Kelun-Biotech it was terminating an additional candidate under the agreement. In July 2024, Merck notified Kelun-Biotech that it was exercising an existing license option for one of the candidates under the agreement, granting Merck a license for the development, manufacture and commercialization worldwide excluding China. There are now three candidates licensed under the original agreement and one candidate for which the license option remains unexercised. Merck will pay Kelun-Biotech $38 million in connection with the July option exercise, following which Kelun-Biotech remains eligible to receive future contingent payments aggregating up to $540 million in development-related payments, $1.5 billion in regulatory milestones, and $3.1 billion in sales-based milestones if Kelun-Biotech does not retain Chinese mainland, Hong Kong and Macau rights for the remaining option ADC and all remaining candidates achieve regulatory approval. In addition, Kelun-Biotech is eligible to receive tiered royalties ranging from a mid-single-digit rate to a low-double-digit rate on future net sales for any commercialized ADC product. Also, in connection with the agreement, Merck invested $100 million in Kelun-Biotech shares in January 2023. In January 2023, Merck acquired Imago BioSciences, Inc. (Imago), a clinical stage biopharmaceutical company developing new medicines for the treatment of myeloproliferative neoplasms and other bone marrow diseases, for $1.35 billion (including payments to settle share-based equity awards) and also incurred approximately $60 million of transaction costs. Imago’s lead candidate, bomedemstat (MK-3543, formerly IMG-7289), is an investigational orally available lysine-specific demethylase 1 inhibitor currently being evaluated in multiple clinical trials for the treatment of essential thrombocythemia, myelofibrosis, and polycythemia vera, in addition to other indications. A Phase 3 clinical trial evaluating bomedemstat for the treatment of certain patients with essential thrombocythemia is underway. The transaction was accounted for as an asset acquisition since bomedemstat represented substantially all of the fair value of the gross assets acquired (excluding cash and deferred income taxes). Merck recorded net assets of $219 million, as well as a charge of $1.2 billion to Research and development expenses in the first six months of 2023 related to the transaction. There are no future contingent payments associated with the acquisition. Spin-Off of Organon & Co. In connection with the 2021 spin-off of Organon & Co. (Organon), Merck and Organon entered into a series of interim operating agreements pursuant to which in various jurisdictions where Merck held licenses, permits and other rights in connection with marketing, import and/or distribution of Organon products prior to the separation, Merck continued to market, import and distribute such products on behalf of Organon until such time as the relevant licenses and permits transferred to Organon, with Organon receiving all of the economic benefits and burdens of such activities. As of June 30, 2024, only one jurisdiction remains under an interim operating agreement. Additionally, Merck and Organon entered into a number of manufacturing and supply agreements (MSAs) with terms ranging from four years to ten years. The amounts included in the condensed consolidated statement of operations for the above MSAs include sales of $93 million and $96 million and related cost of sales of $92 million and $101 million for the second quarter of 2024 and 2023, respectively, and sales of $201 million and $191 million and related cost of sales of $202 million and $208 million for the first six months of 2024 and 2023, respectively. The amounts due from Organon for all spin-off related agreements were $557 million and $632 million at June 30, 2024 and December 31, 2023, respectively, and are reflected in Other current assets . The amounts due to Organon under these agreements were $102 million and $598 million at June 30, 2024 and December 31, 2023, respectively, and are included in Accrued and other current liabilities .

Collaborative Arrangements

Collaborative Arrangements	6 Months Ended
	Jun. 30, 2024
Collaborative Arrangements [Abstract]
Collaborative Arrangements	Collaborative Arrangements Merck has entered into collaborative arrangements that provide the Company with varying rights to develop, produce and market products together with its collaborative partners. Both parties in these arrangements are active participants and exposed to significant risks and rewards dependent on the commercial success of the activities of the collaboration. Merck’s more significant collaborative arrangements are discussed below. AstraZeneca PLC In 2017, Merck and AstraZeneca PLC (AstraZeneca) entered into a global strategic oncology collaboration to co-develop and co-commercialize AstraZeneca’s Lynparza (olaparib) for multiple cancer types. Independently, Merck and AstraZeneca are developing and commercializing Lynparza in combinations with their respective PD-1 and PD-L1 medicines, Keytruda (pembrolizumab) and Imfinzi. The companies are also jointly developing and commercializing AstraZeneca’s Koselugo (selumetinib) for multiple indications. Under the terms of the agreement, AstraZeneca and Merck share the development and commercialization costs for Lynparza and Koselugo monotherapy and non-PD-L1/PD-1 combination therapy opportunities. Profits from Lynparza and Koselugo product sales generated through monotherapies or combination therapies are shared equally. AstraZeneca is the principal on Lynparza and Koselugo sales transactions. Merck records its share of Lynparza and Koselugo product sales, net of cost of sales and commercialization costs, as alliance revenue, and its share of development costs associated with the collaboration as part of Research and development expenses. Reimbursements received from AstraZeneca for research and development expenses are recognized as reductions to Research and development costs. As part of the agreement, Merck made an upfront payment to AstraZeneca and also made payments over a multi-year period for certain license options. In addition, the agreement provides for contingent payments from Merck to AstraZeneca related to the successful achievement of sales-based and regulatory milestones. In 2022, Merck determined it was probable that sales of Lynparza in the future would trigger a $600 million sales-based milestone payment from Merck to AstraZeneca. Accordingly, Merck recorded a $600 million liability (which remained accrued at June 30, 2024) and a corresponding increase to the intangible asset related to Lynparza. Potential future sales-based milestone payments of $2.1 billion have not yet been accrued as they are not deemed by the Company to be probable at this time. Lynparza received regulatory approvals triggering capitalized milestone payments from Merck to AstraZeneca of $245 million and $105 million in the first six months of 2024 and 2023, respectively (each of which had been previously accrued for). In the second quarter of 2024, the partners agreed that no future regulatory milestone payments from Merck to AstraZeneca are likely under the agreement. The intangible asset balance related to Lynparza (which includes capitalized sales-based and regulatory milestone payments) was $1.3 billion at June 30, 2024 and is included in Other Intangibles, Net . The amount is being amortized over its estimated useful life through 2028 as supported by projected future cash flows, subject to impairment testing. Summarized financial information related to this collaboration is as follows: Three Months Ended Six Months Ended ($ in millions) 2024 2023 2024 2023 Alliance revenue - Lynparza $ 317 $ 310 $ 609 $ 585 Alliance revenue - Koselugo 37 25 75 48 Total alliance revenue $ 354 $ 335 $ 684 $ 633 Cost of sales (1) 82 78 163 148 Selling, general and administrative 43 51 82 98 Research and development 18 22 38 43 ($ in millions) June 30, 2024 December 31, 2023 Receivables from AstraZeneca included in Other current assets $ 349 $ 341 Payables to AstraZeneca included in Accrued and other current liabilities (2) 615 256 Payables to AstraZeneca included in Other Noncurrent Liabilities (2) — 600 (1) Represents amortization of capitalized milestone payments. (2) Includes accrued milestone payments. Eisai Co., Ltd. In 2018, Merck and Eisai Co., Ltd. (Eisai) announced a strategic collaboration for the worldwide co-development and co-commercialization of Lenvima (lenvatinib), an orally available tyrosine kinase inhibitor discovered by Eisai. Under the agreement, Merck and Eisai are developing and commercializing Lenvima jointly, both as monotherapy and in combination with Keytruda . Eisai records Lenvima product sales globally (Eisai is the principal on Lenvima sales transactions) and Merck and Eisai share applicable profits equally. Merck records its share of Lenvima product sales, net of cost of sales and commercialization costs, as alliance revenue. Expenses incurred during co-development are shared by the two companies in accordance with the collaboration agreement and reflected in Research and development expenses. Certain expenses incurred solely by Merck or Eisai are not shareable under the collaboration agreement, including costs incurred in excess of agreed upon caps and costs related to certain combination studies of Keytruda and Lenvima. Under the agreement, Merck made an upfront payment to Eisai and also made payments over a multi-year period for certain option rights. In addition, the agreement provides for contingent payments from Merck to Eisai related to the successful achievement of sales-based and regulatory milestones. In the first quarter of 2023, Merck determined it was probable that sales of Lenvima in the future would trigger a $125 million sales-based milestone payment from Merck to Eisai. Similarly, in the third quarter of 2023 an additional $125 million sales-based milestone payment to Eisai was deemed by the Company to be probable of payment. Accordingly, Merck recorded $250 million of liabilities for these payments (one of which was paid in the second quarter of 2023 and the other was paid in the second quarter of 2024) and corresponding increases to the intangible asset related to Lenvima. Merck also recognized $72 million and $81 million of cumulative amortization catch-up expense related to the recognition of these milestones in the first and third quarters of 2023, respectively. Potential future sales-based milestone payments of $2.3 billion have not yet been accrued as they are not deemed by the Company to be probable at this time. There are no regulatory milestone payments remaining under the agreement. The intangible asset balance related to Lenvima (which includes capitalized sales-based and regulatory milestone payments) was $563 million at June 30, 2024 and is included in Other Intangibles, Net . The amount is being amortized over its estimated useful life through 2026 as supported by projected future cash flows, subject to impairment testing. Summarized financial information related to this collaboration is as follows: Three Months Ended Six Months Ended ($ in millions) 2024 2023 2024 2023 Alliance revenue - Lenvima $ 249 $ 242 $ 504 $ 474 Cost of sales (1) 60 57 121 183 Selling, general and administrative 41 48 80 99 Research and development 6 17 13 56 ($ in millions) June 30, 2024 December 31, 2023 Receivables from Eisai included in Other current assets $ 245 $ 226 Payables to Eisai included in Accrued and other current liabilities (2) — 125 (1) Represents amortization of capitalized milestone payments. Amount in the first six months of 2023 includes $72 million of cumulative amortization catch-up expense as noted above. (2) Represents an accrued milestone payment. Bayer AG In 2014, the Company entered into a worldwide clinical development collaboration with Bayer AG (Bayer) to market and develop soluble guanylate cyclase (sGC) modulators including Bayer’s Adempas (riociguat) and Verquvo (vericiguat). The two companies have implemented a joint development and commercialization strategy. Under the agreement, Bayer commercializes Adempas in the Americas, while Merck commercializes in the rest of the world. For Verquvo, Merck commercializes in the U.S. and Bayer commercializes in the rest of the world. Both companies share in development costs and profits on sales. Merck records sales of Adempas and Verquvo in its marketing territories, as well as alliance revenue. Alliance revenue represents Merck’s share of profits from sales of Adempas and Verquvo in Bayer’s marketing territories, which are product sales net of cost of sales and commercialization costs. Cost of sales includes Bayer’s share of profits from sales in Merck’s marketing territories. In addition, the agreement provided for contingent payments from Merck to Bayer related to the successful achievement of sales-based milestones. There are no sales-based milestone payments remaining under this collaboration. The intangible asset balances related to Adempas (which includes the acquired intangible asset balance, as well as capitalized sales-based milestone payments attributed to Adempas) and Verquvo (which reflects the portion of the final sales-based milestone payment that was attributed to Verquvo) were $445 million and $47 million, respectively, at June 30, 2024 and are included in Other Intangibles, Net . The assets are being amortized over their estimated useful lives (through 2027 for Adempas and through 2031 for Verquvo) as supported by projected future cash flows, subject to impairment testing. Summarized financial information related to this collaboration is as follows: Three Months Ended Six Months Ended ($ in millions) 2024 2023 2024 2023 Alliance revenue - Adempas/Verquvo $ 106 $ 68 $ 203 $ 167 Net sales of Adempas recorded by Merck 72 65 142 125 Net sales of Verquvo recorded by Merck 9 9 16 16 Total sales $ 187 $ 142 $ 361 $ 308 Cost of sales (1) 61 56 123 113 Selling, general and administrative 26 34 59 67 Research and development 28 25 55 50 ($ in millions) June 30, 2024 December 31, 2023 Receivables from Bayer included in Other current assets $ 170 $ 156 Payables to Bayer included in Accrued and other current liabilities 81 80 (1) Includes amortization of intangible assets, cost of products sold by Merck, as well as Bayer’s share of profits from sales in Merck’s marketing territories. Ridgeback Biotherapeutics LP In 2020, Merck and Ridgeback Biotherapeutics LP (Ridgeback), a closely held biotechnology company, entered into a collaboration agreement to develop Lagevrio (molnupiravir), an investigational orally available antiviral candidate for the treatment of patients with COVID-19. Merck gained exclusive worldwide rights to develop and commercialize Lagevrio and related molecules. Following initial authorizations in certain markets in the fourth quarter of 2021, Lagevrio has since received multiple additional authorizations. Under the terms of the agreement, Ridgeback received an upfront payment and is eligible to receive future contingent payments dependent upon the achievement of certain developmental and regulatory approval milestones. The agreement also provides for Merck to reimburse Ridgeback for a portion of certain third-party contingent milestone payments and royalties on net sales, which is part of the profit-sharing calculation. Merck is the principal on sales transactions, recognizing sales and related costs, with profit-sharing amounts recorded within Cost of sales . Profits from the collaboration are split equally between the partners. Reimbursements from Ridgeback for its share of research and development costs (deducted from Ridgeback’s share of profits) are reflected as decreases to Research and development expenses. Summarized financial information related to this collaboration is as follows: Three Months Ended Six Months Ended ($ in millions) 2024 2023 2024 2023 Net sales of Lagevrio recorded by Merck $ 110 $ 203 $ 460 $ 595 Cost of sales (1) 96 193 287 414 Selling, general and administrative 16 24 32 51 Research and development 7 10 2 26 ($ in millions) June 30, 2024 December 31, 2023 Receivables from Ridgeback included in Other current assets $ 8 $ — Payables to Ridgeback included in Accrued and other current liabilities (2) 24 113 (1) Includes cost of products sold by Merck, Ridgeback’s share of profits, royalty expense, amortization of capitalized milestone payments and inventory reserves. (2) Includes accrued royalties. Daiichi Sankyo In October 2023, Merck and Daiichi Sankyo entered into a global development and commercialization agreement for three of Daiichi Sankyo’s DXd ADC candidates: patritumab deruxtecan (HER3-DXd) (MK-1022), ifinatamab deruxtecan (I-DXd) (MK-2400) and raludotatug deruxtecan (R-DXd) (MK-5909). All three potentially first-in-class DXd ADCs are in various stages of clinical development for the treatment of multiple solid tumors both as monotherapy and/or in combination with other treatments. The companies will jointly develop and potentially commercialize these ADC candidates worldwide, except in Japan where Daiichi Sankyo will maintain exclusive rights. Daiichi Sankyo will be solely responsible for manufacturing and supply. Under the terms of the agreement, Merck made payments to Daiichi Sankyo totaling $4.0 billion in 2023. These payments included $1.0 billion ($500 million each for patritumab deruxtecan and ifinatamab deruxtecan) which may be refundable on a pro-rated basis in the event of early termination of development with respect to either program. In addition, the agreement provides for a continuation payment of $750 million related to patritumab deruxtecan due from Merck in October 2024 and a continuation payment of $750 million related to raludotatug deruxtecan due from Merck in October 2025. If Merck does not make the continuation payments on the dates noted for either patritumab deruxtecan and/or raludotatug deruxtecan, the rights for the applicable program will revert to Daiichi Sankyo and the non-refundable upfront payments already paid will be retained by Daiichi Sankyo. The agreement also provides for contingent payments from Merck to Daiichi Sankyo of up to an additional $5.5 billion for each DXd ADC upon the successful achievement of certain sales-based milestones. In conjunction with this transaction, Merck recorded an aggregate pretax charge of $5.5 billion to Research and development expenses in the fourth quarter of 2023 for the $4.0 billion of upfront payments and the $1.5 billion of continuation payments. Merck and Daiichi Sankyo equally share research and development costs, except for raludotatug deruxtecan, where Merck is responsible for 75% of the first $2.0 billion of research and development expenses. Merck includes its share of development costs associated with the collaboration as part of Research and development expenses. Following regulatory approval, Daiichi Sankyo will generally record sales worldwide (Daiichi Sankyo will be the principal on sales transactions) and the companies will equally share expenses as well as profits worldwide except for Japan where Daiichi Sankyo retains exclusive rights and Merck will receive a 5% sales-based royalty. Merck will record its share of product sales, net of cost of sales and commercialization costs, as alliance revenue. Summarized financial information related to this collaboration is as follows: Three Months Ended Six Months Ended ($ in millions) 2024 2023 2024 2023 Selling, general and administrative $ 14 $ — $ 16 $ — Research and development 65 — 133 — ($ in millions) June 30, 2024 December 31, 2023 Payables to Daiichi Sankyo included in Accrued and other current liabilities $ 801 $ 800 Payables to Daiichi Sankyo included in Other Noncurrent Liabilities 750 750 Moderna, Inc. In 2022, Merck exercised its option to jointly develop and commercialize V940 (mRNA-4157), an investigational individualized neoantigen therapy, pursuant to the terms of an existing collaboration and license agreement with Moderna, Inc. (Moderna). V940 (mRNA-4157) is currently being evaluated in combination with Keytruda in multiple Phase 3 clinical trials. Merck and Moderna will share costs and any profits equally under this worldwide collaboration. Merck records its share of development costs associated with the collaboration as part of Research and development expenses. Any reimbursements received from Moderna for research and development expenses are recognized as reductions to Research and development costs. Merck has also capitalized certain of the shared costs, which aggregated $135 million at June 30, 2024 and will be amortized over the assets’ estimated useful lives. Summarized financial information related to this collaboration is as follows: Three Months Ended Six Months Ended ($ in millions) 2024 2023 2024 2023 Selling, general and administrative $ 4 $ 1 $ 6 $ 2 Research and development 93 60 162 86 ($ in millions) June 30, 2024 December 31, 2023 Payables to Moderna included in Accrued and other current liabilities $ 73 $ 63 Bristol-Myers Squibb Company Reblozyl (luspatercept-aamt) is a first-in-class erythroid maturation recombinant fusion protein that is being commercialized through a global collaboration with Bristol-Myers Squibb Company (BMS). Reblozyl is approved in the U.S., Europe and certain other markets for the treatment of anemia in certain rare blood disorders and is also being evaluated for additional indications for hematology therapies. BMS is the principal on sales transactions for Reblozyl; however, Merck co-promotes Reblozyl (and will co-promote all future products approved under this collaboration) in North America, which is reimbursed by BMS. Merck receives tiered royalties ranging from 20% to 24% based on sales levels. This royalty will be reduced by 50% upon the earlier of patent expiry or generic entry on an indication-by-indication basis in each market. Additionally, Merck is eligible to receive future contingent sales-based milestone payments of up to $80 million. Alliance revenue related to this collaboration, consisting of royalties (recorded within Sales ) was $90 million and $161 million in the second quarter and first six months of 2024, respectively, compared with $47 million and $90 million in the second quarter and first six months of 2023, respectively.

Restructuring

Restructuring	6 Months Ended
	Jun. 30, 2024
Restructuring and Related Activities [Abstract]
Restructuring	Restructuring In January 2024, the Company approved a new restructuring program (2024 Restructuring Program) intended to continue the optimization of the Company’s Human Health global manufacturing network as the future pipeline shifts to new modalities and also optimize the Animal Health global manufacturing network to improve supply reliability and increase efficiency. The actions contemplated under the 2024 Restructuring Program are expected to be substantially completed by the end of 2031, with the cumulative pretax costs to be incurred by the Company to implement the program estimated to be approximately $4.0 billion. Approximately 60% of the cumulative pretax costs will be non-cash, relating primarily to the accelerated depreciation of facilities to be closed or divested. The remainder of the costs will result in cash outlays, relating primarily to facility shut-down costs. The Company recorded total pretax costs of $177 million and $422 million in the second quarter and first six months of 2024, respectively, related to the 2024 Restructuring Program, bringing total cumulative pretax costs incurred through June 30, 2024 to $613 million. In 2019, Merck approved a global restructuring program (2019 Restructuring Program) as part of a worldwide initiative focused on optimizing the Company’s manufacturing and supply network, as well as reducing its global real estate footprint. The Company recorded total pretax costs of $236 million and $333 million in the second quarter and first six months of 2023, respectively, related to the 2019 Restructuring Program. The actions under the 2019 Restructuring Program were substantially complete at the end of 2023 and, as of January 1, 2024, any remaining activities are now being accounted for as part of the 2024 Restructuring Program. For segment reporting, restructuring charges are unallocated expenses. The following tables summarize the charges related to the restructuring programs by type of cost: Three Months Ended June 30, 2024 Six Months Ended June 30, 2024 ($ in millions) Accelerated Depreciation Separation Costs Other Exit Costs Total Accelerated Depreciation Separation Costs Other Total 2024 Restructuring Program Cost of sales $ 66 $ — $ — $ 66 $ 131 $ — $ 51 $ 182 Selling, general and administrative — — 31 31 — — 36 36 Research and development — — — — — — 2 2 Restructuring costs — 19 61 80 — 111 91 202 $ 66 $ 19 $ 92 $ 177 $ 131 $ 111 $ 180 $ 422 Three Months Ended June 30, 2023 Six Months Ended June 30, 2023 ($ in millions) Accelerated Depreciation Separation Costs Other Exit Costs Total Accelerated Depreciation Separation Costs Other Total 2019 Restructuring Program Cost of sales $ 22 $ — $ 10 $ 32 $ 43 $ — $ 18 $ 61 Selling, general and administrative — — 52 52 — — 53 53 Research and development — — 1 1 — — 1 1 Restructuring costs — 110 41 151 — 151 67 218 $ 22 $ 110 $ 104 $ 236 $ 43 $ 151 $ 139 $ 333 Accelerated depreciation costs primarily relate to manufacturing, research and administrative facilities and equipment to be sold or closed as part of the programs. Accelerated depreciation costs represent the difference between the depreciation expense to be recognized over the revised useful life of the asset, based upon the anticipated date the site will be closed or divested or the equipment disposed of, and depreciation expense as determined utilizing the useful life prior to the restructuring actions. All the sites will continue to operate up through the respective closure dates and, since future undiscounted cash flows are sufficient to recover the respective book values, Merck is recording accelerated depreciation over the revised useful life of the site assets. Anticipated site closure dates, particularly related to manufacturing locations, have been and may continue to be adjusted to reflect changes resulting from regulatory or other factors. Separation costs are associated with actual headcount reductions, as well as involuntary headcount reductions which were probable and could be reasonably estimated. Other exit costs in 2024 and 2023 include asset abandonment, facility shut-down and other related costs, as well as pretax gains and losses resulting from the sales of facilities and related assets. Additionally, other activity includes certain employee-related costs associated with pension and other postretirement benefit plans (see Note 10) and share-based compensation. The following table summarizes the charges and spending relating to restructuring program activities for the six months ended June 30, 2024: ($ in millions) Accelerated Depreciation Separation Costs Other Exit Costs Total Restructuring reserves January 1, 2024 $ — $ 681 $ 31 $ 712 Expenses 131 111 180 422 (Payments) receipts, net — (132) (73) (205) Non-cash activity (131) — (111) (242) Restructuring reserves June 30, 2024 $ — $ 660 $ 27 $ 687

Financial Instruments

Financial Instruments	6 Months Ended
	Jun. 30, 2024
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Financial Instruments	Financial Instruments Derivative Instruments and Hedging Activities The Company manages the impact of foreign exchange rate movements and interest rate movements on its earnings, cash flows and fair values of assets and liabilities through operational means and through the use of various financial instruments, including derivative instruments. A significant portion of the Company’s revenues and earnings in foreign affiliates is exposed to changes in foreign exchange rates. The objectives of and accounting related to the Company’s foreign currency risk management program, as well as its interest rate risk management activities are discussed below. Foreign Currency Risk Management The Company has established revenue hedging, balance sheet risk management and net investment hedging programs to protect against volatility of future foreign currency cash flows and changes in fair value caused by changes in foreign exchange rates. The objective of the revenue hedging program is to reduce the variability caused by changes in foreign exchange rates that would affect the U.S. dollar value of future cash flows derived from foreign currency denominated sales, primarily the euro, Japanese yen and Chinese renminbi. To achieve this objective, the Company will hedge a portion of its forecasted foreign currency denominated third-party and intercompany distributor entity sales (forecasted sales) that are expected to occur over its planning cycle, typically no more than two years into the future. The Company will layer in hedges over time, increasing the portion of forecasted sales hedged as it gets closer to the expected date of the forecasted sales. The portion of forecasted sales hedged is based on assessments of cost-benefit profiles that consider natural offsetting exposures, revenue and foreign exchange rate volatilities and correlations, and the cost of hedging instruments. The Company manages its anticipated transaction exposure principally with purchased local currency put options, forward contracts, and purchased collar options. The fair values of these derivative contracts are recorded as either assets (gain positions) or liabilities (loss positions) in the Condensed Consolidated Balance Sheet. Changes in the fair value of derivative contracts are recorded each period in either current earnings or Other comprehensive income ( OCI ), depending on whether the derivative is designated as part of a hedge transaction and, if so, the type of hedge transaction. For derivatives that are designated as cash flow hedges, the unrealized gains or losses on these contracts are recorded in Accumulated Other Comprehensive Loss ( AOCL) and reclassified into Sales when the hedged anticipated revenue is recognized. For those derivatives which are not designated as cash flow hedges, but serve as economic hedges of forecasted sales, unrealized gains or losses are recorded in Sales each period. The cash flows from both designated and non-designated contracts are reported as operating activities in the Condensed Consolidated Statement of Cash Flows. The Company does not enter into derivatives for trading or speculative purposes. The Company manages operating activities and net asset positions at each local subsidiary in order to mitigate the effects of foreign exchange on monetary assets and liabilities. Monetary assets and liabilities denominated in a currency other than the functional currency of a given subsidiary are remeasured at spot rates in effect on the balance sheet date with the effects of changes in spot rates reported in Other (income) expense, net . The Company also uses a balance sheet risk management program to mitigate the exposure of such assets and liabilities from the effects of volatility in foreign exchange. Merck principally utilizes forward exchange contracts to offset the effects of foreign exchange on exposures when it is deemed economical to do so based on a cost-benefit analysis that considers the magnitude of the exposure, the volatility of the foreign exchange rate and the cost of the hedging instrument (primarily the euro, Swiss franc, Japanese yen, and Chinese renminbi). The forward contracts are not designated as hedges and are marked to market through Other (income) expense, net . Accordingly, fair value changes in the forward contracts help mitigate the changes in the value of the remeasured assets and liabilities attributable to changes in foreign currency exchange rates, except to the extent of the spot-forward differences. These differences are not significant due to the short-term nature of the contracts, which typically have average maturities at inception of less than six months. The cash flows from these contracts are reported as operating activities in the Condensed Consolidated Statement of Cash Flows. The Company also uses forward exchange contracts to hedge a portion of its net investment in foreign operations against movements in foreign exchange rates. The forward contracts are designated as hedges of the net investment in a foreign operation. The unrealized gains or losses on these contracts are recorded in foreign currency translation adjustment within OCI and remain in AOCL until either the sale or complete or substantially complete liquidation of the subsidiary. The Company excludes certain portions of the change in fair value of its derivative instruments from the assessment of hedge effectiveness (excluded components). Changes in fair value of the excluded components are recognized in OCI . The Company recognizes in earnings the initial value of the excluded components on a straight-line basis over the life of the derivative instrument, rather than using the mark-to-market approach. The cash flows from these contracts are reported as investing activities in the Condensed Consolidated Statement of Cash Flows. Foreign exchange risk is also managed through the use of foreign currency debt. A portion of the Company’s senior unsecured euro-denominated notes have been designated as, and are effective as, economic hedges of the net investment in a foreign operation. Accordingly, foreign currency transaction gains or losses due to spot rate fluctuations on the euro-denominated debt instruments are included in foreign currency translation adjustment within OCI . The effects of the Company’s net investment hedges on OCI and the Condensed Consolidated Statement of Income are shown below: Amount of Pretax (Gain) Loss Recognized in Other Comprehensive Income (1) Amount of Pretax Loss Recognized in Other (income) expense, net for Amounts Excluded from Effectiveness Testing Three Months Ended June 30, Six Months Ended June 30, Three Months Ended June 30, Six Months Ended June 30, ($ in millions) 2024 2023 2024 2023 2024 2023 2024 2023 Net Investment Hedging Relationships Foreign exchange contracts $ 5 $ — $ 3 $ 1 $ (1) $ — $ (1) $ 1 Euro-denominated notes (34) 21 (96) 73 — — — — (1) No amounts were reclassified from AOCL into income related to the sale of a subsidiary. Interest Rate Risk Management The Company may use interest rate swap contracts on certain investing and borrowing transactions to manage its net exposure to interest rate changes and to reduce its overall cost of borrowing. The Company does not use leveraged swaps and, in general, does not leverage any of its investment activities that would put principal at risk. At June 30, 2024, the Company was a party to six pay-floating, receive-fixed interest rate swap contracts designated as fair value hedges of a portion of fixed-rate notes as detailed in the table below. June 30, 2024 ($ in millions) Par Value of Debt Number of Interest Rate Swaps Held Total Swap Notional Amount 4.50% notes due 2033 $ 1,500 6 $ 1,500 The interest rate swap contracts are designated hedges of the fair value changes in the notes attributable to changes in the benchmark Secured Overnight Financing Rate (SOFR) swap rate. The fair value changes in the notes attributable to changes in the SOFR swap rate are recorded in interest expense along with the offsetting fair value changes in the swap contracts. The cash flows from these contracts are reported as operating activities in the Condensed Consolidated Statement of Cash Flows. The table below presents the location of amounts recorded in the Condensed Consolidated Balance Sheet related to cumulative basis adjustments for fair value hedges: Carrying Amount of Hedged Liabilities Cumulative Amount of Fair Value Hedging Adjustment Increase Included in the Carrying Amount ($ in millions) June 30, 2024 December 31, 2023 June 30, 2024 December 31, 2023 Balance Sheet Caption Long-Term Debt $ 1,521 $ 1,056 $ 30 $ 56 Presented in the table below is the fair value of derivatives on a gross basis segregated between those derivatives that are designated as hedging instruments and those that are not designated as hedging instruments: June 30, 2024 December 31, 2023 Fair Value of Derivative U.S. Dollar Fair Value of Derivative U.S. Dollar ($ in millions) Asset Liability Asset Liability Derivatives Designated as Hedging Instruments Balance Sheet Caption Interest rate swap contracts Other Assets $ 30 $ — $ 1,500 $ 57 $ — $ 1,000 Foreign exchange contracts Other current assets 226 — 8,830 106 — 6,138 Foreign exchange contracts Other Assets 46 — 2,052 26 — 1,929 Foreign exchange contracts Accrued and other current liabilities — 4 901 — 76 3,680 Foreign exchange contracts Other Noncurrent Liabilities — 1 230 — 1 7 302 5 13,513 189 77 12,754 Derivatives Not Designated as Hedging Instruments Balance Sheet Caption Foreign exchange contracts Other current assets 187 — 8,723 153 — 9,693 Foreign exchange contracts Other Assets 2 — 22 — — — Foreign exchange contracts Accrued and other current liabilities — 135 10,818 — 162 8,104 Foreign exchange contracts Other Noncurrent Liabilities — 2 22 — — — 189 137 19,585 153 162 17,797 $ 491 $ 142 $ 33,098 $ 342 $ 239 $ 30,551 As noted above, the Company records its derivatives on a gross basis in the Condensed Consolidated Balance Sheet. The Company has master netting agreements with several of its financial institution counterparties (see Concentrations of Credit Risk below). The following table provides information on the Company’s derivative positions subject to these master netting arrangements as if they were presented on a net basis, allowing for the right of offset by counterparty and cash collateral exchanged per the master agreements and related credit support annexes: June 30, 2024 December 31, 2023 ($ in millions) Asset Liability Asset Liability Gross amounts recognized in the condensed consolidated balance sheet $ 491 $ 142 $ 342 $ 239 Gross amounts subject to offset in master netting arrangements not offset in the condensed consolidated balance sheet (114) (114) (215) (215) Cash collateral received (123) — (3) — Net amounts $ 254 $ 28 $ 124 $ 24 The table below provides information regarding the location and amount of pretax gains and losses of derivatives designated in fair value or cash flow hedging relationships: Three Months Ended June 30, Six Months Ended June 30, ($ in millions) 2024 2023 2024 2023 2024 2023 2024 2023 2024 2023 2024 2023 Financial Statement Caption in which Effects of Fair Value or Cash Flow Sales Other (income) expense, net (1) Other comprehensive income (loss) Sales Other (income) expense, net (1) Other comprehensive income (loss) $ 16,112 $ 15,035 $ 42 $ 172 $ (87) $ (17) $ 31,887 $ 29,522 $ 12 $ 259 $ (200) $ (132) (Gain) loss on fair value hedging relationships: Interest rate swap contracts Hedged items — — 4 — — — — — (26) — — — Derivatives designated as hedging instruments — — (4) — — — — — 27 — — — Impact of cash flow hedging relationships: Foreign exchange contracts Amount of gain recognized in OCI on derivatives — — — — 139 194 — — — — 348 128 Increase in Sales as a result of AOCL reclassifications 54 24 — — (54) (24) 98 125 — — (98) (125) Interest rate contracts Amount of gain recognized in Other (income) expense, net on derivatives — — — — — — — — (1) (1) — — Amount of gain recognized in OCI on derivatives — — — — — 13 — — — — (1) 13 (1) Interest expense is a component of Other (income) expense, net. The table below provides information regarding the income statement effects of derivatives not designated as hedging instruments: Amount of Derivative Pretax (Gain) Loss Recognized in Income Three Months Ended June 30, Six Months Ended June 30, ($ in millions) 2024 2023 2024 2023 Derivatives Not Designated as Hedging Instruments Income Statement Caption Foreign exchange contracts (1) Other (income) expense, net $ 9 $ (41) $ 75 $ (28) Foreign exchange contracts (2) Sales (10) (5) (20) (3) (1) These derivative contracts primarily mitigate changes in the value of remeasured foreign currency denominated monetary assets and liabilities attributable to changes in foreign currency exchange rates. (2) These derivative contracts serve as economic hedges of forecasted transactions . At June 30, 2024, the Company estimates $190 million of pretax net unrealized gains on derivatives maturing within the next 12 months that hedge foreign currency denominated sales over that same period will be reclassified from AOCL to Sales . The amount ultimately reclassified to Sales may differ as foreign exchange rates change. Realized gains and losses are ultimately determined by actual foreign exchange rates at maturity. Investments in Debt and Equity Securities Information on investments in debt and equity securities is as follows: June 30, 2024 December 31, 2023 Amortized Gross Unrealized Fair Amortized Gross Unrealized Fair ($ in millions) Gains Losses Gains Losses U.S. government and agency securities $ 77 $ — $ — $ 77 $ 72 $ — $ — $ 72 Commercial paper 50 — — 50 252 — — 252 Corporate notes and bonds — — — — 13 — — 13 Total debt securities $ 127 $ — $ — $ 127 $ 337 $ — $ — $ 337 Publicly traded equity securities (1) 1,026 764 Total debt and publicly traded equity securities $ 1,153 $ 1,101 (1) Unrealized net losses (gains) of $8 million and $(125) million were recorded in Other (income) expense, net in the second quarter and first six months of 2024, respectively, on equity securities still held at June 30, 2024. Unrealized net losses (gains) of $71 million and $(267) million were recorded in Other (income) expense, net in the second quarter and first six months of 2023, respectively, on equity securities still held at June 30, 2023. At June 30, 2024 and June 30, 2023, the Company also had $936 million and $949 million, respectively, of equity investments without readily determinable fair values included in Other Assets . The Company records unrealized gains on these equity investments based on favorable observable price changes from transactions involving similar investments of the same investee and records unrealized losses based on unfavorable observable price changes, which are included in Other (income) expense, net . During the first six months of 2024 , the Company recorded unrealized gains of $61 million and unrealized losses of $5 million related to certain of these equity investments still held at June 30, 2024. During the first six months of 2023 , the Company recorded unrealized gains of $3 million and unrealized losses of $23 million related to certain of these equity investments still held at June 30, 2023. Cumulative unrealized gains and cumulative unrealized losses based on observable price changes for investments in equity investments without readily determinable fair values still held at June 30, 2024 were $355 million and $69 million, respectively. At June 30, 2024 and June 30, 2023, the Company also had $278 million and $622 million, respectively, recorded in Other Assets for equity securities held through ownership interests in investment funds. (Gains) losses recorded in Other (income) expense, net relating to these investment funds were $(7) million and $105 million for the second quarter of 2024 and 2023, respectively, and were $(5) million and $(27) million for the first six months of 2024 and 2023, respectively. Fair Value Measurements Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The Company uses a fair value hierarchy which maximizes the use of observable inputs and minimizes the use of unobservable inputs when measuring fair value. There are three levels of inputs used to measure fair value with Level 1 having the highest priority and Level 3 having the lowest: Level 1 - Quoted prices (unadjusted) in active markets for identical assets or liabilities. Level 2 - Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 - Unobservable inputs that are supported by little or no market activity. Level 3 assets or liabilities are those whose values are determined using pricing models, discounted cash flow methodologies, or similar techniques with significant unobservable inputs, as well as assets or liabilities for which the determination of fair value requires significant judgment or estimation. If the inputs used to measure the financial assets and liabilities fall within more than one level described above, the categorization is based on the lowest level input that is significant to the fair value measurement of the instrument. Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis Financial assets and liabilities measured at fair value on a recurring basis are summarized below: Fair Value Measurements Using Fair Value Measurements Using Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total ($ in millions) June 30, 2024 December 31, 2023 Assets Investments Commercial paper $ — $ 50 $ — $ 50 $ — $ 252 $ — $ 252 Publicly traded equity securities 357 — — 357 252 — — 252 357 50 — 407 252 252 — 504 Other assets (1) U.S. government and agency securities 77 — — 77 72 — — 72 Corporate notes and bonds — — — — 13 — — 13 Publicly traded equity securities (2) 669 — — 669 512 — — 512 746 — — 746 597 — — 597 Derivative assets (3) Forward exchange contracts — 278 — 278 — 202 — 202 Purchased currency options — 183 — 183 — 83 — 83 Interest rate swaps — 30 — 30 — 57 — 57 — 491 — 491 — 342 — 342 Total assets $ 1,103 $ 541 $ — $ 1,644 $ 849 $ 594 $ — $ 1,443 Liabilities Other liabilities Contingent consideration $ — $ — $ 225 $ 225 $ — $ — $ 354 $ 354 Derivative liabilities (3) Forward exchange contracts — 115 — 115 — 239 — 239 Written currency options — 27 — 27 — — — — — 142 — 142 — 239 — 239 Total liabilities $ — $ 142 $ 225 $ 367 $ — $ 239 $ 354 $ 593 (1) Investments included in other assets are restricted as to use, including for the payment of benefits under employee benefit plans. (2) Balance at June 30, 2024 includes securities with a fair value of $285 million, which were subject to a contractual sale restriction that expired in July 2024. (3) The fair value determination of derivatives includes the impact of the credit risk of counterparties to the derivatives and the Company’s own credit risk, the effects of which were not significant. As of June 30, 2024 and December 31, 2023, Cash and cash equivalents included $10.5 billion and $6.0 billion of cash equivalents, respectively (which would be considered Level 2 in the fair value hierarchy). Contingent Consideration Summarized information about the changes in the fair value of liabilities for contingent consideration associated with business combinations is as follows: ($ in millions) 2024 2023 Fair value January 1 $ 354 $ 456 Changes in estimated fair value (1) (3) 10 Payments (126) (117) Fair value June 30 (2) $ 225 $ 349 (1) Recorded in Cost of sales, Research and development expenses, and Other (income) expense, net . Includes cumulative translation adjustments. (2) Balance at June 30, 2024, includes $131 million of current liabilities, all of which relate to the termination of the Sanofi Pasteur MSD joint venture in 2016. As part of the termination, Merck recorded a liability for contingent future royalty payments of 11.5% on net sales of all Merck products that were previously sold by the joint venture through December 31, 2024. The fair value of this liability is determined utilizing the estimated amount and timing of projected cash flows using a risk-adjusted discount rate to present value the cash flows. The payments of contingent consideration in both periods relate to the Sanofi Pasteur MSD liabilities described above. Other Fair Value Measurements Some of the Company’s financial instruments, such as cash and cash equivalents, receivables and payables, are reflected in the balance sheet at carrying value, which approximates fair value due to their short-term nature. The estimated fair value of loans payable and long-term debt (including current portion) at June 30, 2024, was $33.5 billion compared with a carrying value of $37.8 billion and at December 31, 2023, was $32.0 billion compared with a carrying value of $35.1 billion. Fair value was estimated using recent observable market prices and would be considered Level 2 in the fair value hierarchy. Concentrations of Credit Risk On an ongoing basis, the Company monitors concentrations of credit risk associated with corporate and government issuers of securities and financial institutions with which it conducts business. Credit exposure limits are established to limit a concentration with any single issuer or institution. Cash and investments are placed in instruments that meet high credit quality standards as specified in the Company’s investment policy guidelines. The majority of the Company’s accounts receivable arise from product sales in the U.S., Europe and China and are primarily due from drug wholesalers, distributors and retailers, hospitals and government agencies. The Company monitors the financial performance and creditworthiness of its customers so that it can properly assess and respond to changes in their credit profile. The Company also continues to monitor global economic conditions, including the volatility associated with international sovereign economies, and associated impacts on the financial markets and its business. The Company has accounts receivable factoring agreements with financial institutions in certain countries to sell accounts receivable. The Company factored $2.9 billion and $3.0 billion of accounts receivable as of June 30, 2024 and December 31, 2023, respectively, under these factoring arrangements, which reduced outstanding accounts receivable. The cash received from the financial institutions is reported within operating activities in the Condensed Consolidated Statement of Cash Flows. In certain of these factoring arrangements, for ease of administration, the Company will collect customer payments related to the factored receivables, which it then remits to the financial institutions, generally within thirty days after receipt. As of June 30, 2024 and December 31, 2023, the Company had collected $42 million and $44 million, respectively, on behalf of the financial institutions, which is reflected as restricted cash in Other current assets and the related obligation to remit the cash within Accrued and other current liabilities . The net cash flows related to these collections are reported as financing activities in the Condensed Consolidated Statement of Cash Flows. The cost of factoring such accounts receivable was de minimis . Derivative financial instruments are executed under International Swaps and Derivatives Association master agreements. The master agreements with several of the Company’s financial institution counterparties also include credit support annexes. These annexes contain provisions that require collateral to be exchanged depending on the value of the derivative assets and liabilities, the Company’s credit rating, and the credit rating of the counterparty. Cash collateral received by the Company from various counterparties was $123 million and $3 million at June 30, 2024 and December 31, 2023, respectively. The obligation to return such collateral is recorded in Accrued and other current liabilities

Inventories

Inventories	6 Months Ended
	Jun. 30, 2024
Inventory Disclosure [Abstract]
Inventories	Inventories Inventories consisted of: ($ in millions) June 30, 2024 December 31, 2023 Finished goods $ 1,889 $ 1,954 Raw materials and work in process 8,456 8,037 Supplies 267 277 Total 10,612 10,268 Decrease to LIFO cost (687) (562) $ 9,925 $ 9,706 Recognized as: Inventories $ 6,469 $ 6,358 Other Assets 3,456 3,348 Amounts recognized as Other Assets are comprised almost entirely of raw materials and work in process inventories. At June 30, 2024 and December 31, 2023, these amounts included $3.2 billion and $2.6 billion, respectively, of inventories not expected to be sold within one year. In addition, these amounts included $250 million and $790 million at June 30, 2024 and December 31, 2023, respectively, of inventories produced in preparation for product launches.

Long-Term Debt

Long-Term Debt	6 Months Ended
	Jun. 30, 2024
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term DebtIn May 2024, MSD Netherlands Capital B.V., a wholly-owned finance subsidiary of Merck, completed a registered public offering of €3.4 billion in aggregate principal amount of euro-dominated senior notes comprised of €850 million of 3.25% senior notes due 2032, €850 million of 3.50% senior notes due 2037, €850 million of 3.70% senior notes due 2044 and €850 million of 3.75% senior notes due 2054 (collectively, the Euronotes). The Company has fully and unconditionally guaranteed all of MSD Netherlands Capital B.V.’s obligations under the Euronotes and no other subsidiary of the Company will guarantee these obligations. MSD Netherlands Capital B.V. is a “finance subsidiary” as defined in Rule 13-01(a)(4)(vi) of Regulation S-X of the Exchange Act, with no assets or operations other than those related to the issuance, administration and repayment of the Euronotes. The financial condition, results of operations and cash flows of MSD Netherlands Capital B.V. are consolidated in the financial statements of the Company. The net cash proceeds from the offering were used for general corporate purposes.

Contingencies

Contingencies	6 Months Ended
	Jun. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies The Company is involved in various claims and legal proceedings of a nature considered normal to its business, including product liability, intellectual property, and commercial litigation, as well as certain additional matters including governmental and environmental matters. In the opinion of the Company, it is unlikely that the resolution of these matters will be material to the Company’s financial condition, results of operations or cash flows. Given the nature of the litigation discussed below and the complexities involved in these matters, the Company is unable to reasonably estimate a possible loss or range of possible loss for such matters until the Company knows, among other factors, (i) what claims, if any, will survive dispositive motion practice, (ii) the extent of the claims, including the size of any potential class, particularly when damages are not specified or are indeterminate, (iii) how the discovery process will affect the litigation, (iv) the settlement posture of the other parties to the litigation and (v) any other factors that may have a material effect on the litigation. The Company records accruals for contingencies when it is probable that a liability has been incurred and the amount can be reasonably estimated. These accruals are adjusted periodically as assessments change or additional information becomes available. Generally, for product liability claims, a portion of the overall accrual is actuarially determined and considers such factors as past experience, number of claims reported and estimates of claims incurred but not yet reported. Individually significant contingent losses are accrued when probable and reasonably estimable. Legal defense costs expected to be incurred in connection with a loss contingency are accrued when probable and reasonably estimable. The Company’s decision to obtain insurance coverage is dependent on market conditions, including cost and availability, existing at the time such decisions are made. The Company has evaluated its risks and has determined that the cost of obtaining product liability insurance outweighs the likely benefits of the coverage that is available and, as such, has no insurance for most product liabilities. Product Liability Litigation Dr. Scholl’s Foot Powder As previously disclosed, Merck is a defendant in product liability lawsuits in the U.S. arising from consumers’ alleged exposure to talc in Dr. Scholl’s foot powder, which Merck acquired through its merger with Schering-Plough Corporation and sold as part of the divestiture of Merck’s consumer care business to Bayer in 2014. In these actions, plaintiffs allege that they were exposed to asbestos-contaminated talc and developed mesothelioma as a result. As of June 30, 2024, approximately 290 cases were pending against Merck in various state courts. Gardasil/Gardasil 9 As previously disclosed, Merck is a defendant in product liability lawsuits in the U.S. involving Gardasil (Human Papillomavirus Quadrivalent [Types 6, 11, 16 and 18] Vaccine, Recombinant) and Gardasil 9 (Human Papillomavirus 9-valent Vaccine, Recombinant). As of June 30, 2024, approximately 210 cases were filed and pending against Merck in either federal or state court. In these actions, plaintiffs allege, among other things, that they suffered various personal injuries after vaccination with Gardasil or Gardasil 9, with postural orthostatic tachycardia syndrome as a predominate alleged injury. In August 2022, the U.S. Judicial Panel on Multidistrict Litigation ordered that Gardasil/Gardasil 9 product liability cases pending in federal courts nationwide be transferred to Judge Robert J. Conrad in the Western District of North Carolina for coordinated pre-trial proceedings. In February 2024, the multidistrict litigation was reassigned to Judge Kenneth D. Bell. One state court action in Los Angeles County is scheduled to commence trial on October 7, 2024. As previously disclosed, there are fewer than 15 product liability cases pending outside the U.S. Governmental Proceedings Civil Investigative Demand In June 2024, Merck received a Civil Investigative Demand (CID) from the U.S. Department of Justice, pursuant to a False Claims Act investigation, seeking documents and materials related to Steglatro, Januvia and certain related drugs. The CID states that it is investigating Merck’s price reporting under the Medicaid Drug Rebate Program as well as compliance with anti-kickback requirements in connection with patient assistance programs. The Company is cooperating with the investigation. Other Matters As previously disclosed, from time to time, the Company’s subsidiaries in China receive inquiries regarding their operations from various Chinese governmental agencies. Some of these inquiries may be related to matters involving other multinational pharmaceutical companies, as well as Chinese entities doing business with such companies. The Company’s policy is to cooperate with these authorities and to provide responses as appropriate. As previously disclosed, from time to time, the Company receives inquiries and is the subject of preliminary investigation activities from competition and other governmental authorities in markets outside the U.S. These authorities may include regulators, administrative authorities, and law enforcement and other similar officials, and these preliminary investigation activities may include site visits, formal or informal requests or demands for documents or materials, inquiries or interviews and similar matters. Certain of these preliminary inquiries or activities may lead to the commencement of formal proceedings. Should those proceedings be determined adversely to the Company, monetary fines and/or remedial undertakings may be required. Patent Litigation From time to time, generic manufacturers of pharmaceutical products file abbreviated New Drug Applications (ANDAs) with the U.S. Food and Drug Administration (FDA) seeking to market generic forms of the Company’s products prior to the expiration of relevant patents owned by the Company. To protect its patent rights, the Company may file patent infringement lawsuits against such generic companies. Similar lawsuits defending the Company’s patent rights may exist in other countries. The Company intends to vigorously defend its patents, which it believes are valid, against infringement by companies attempting to market products prior to the expiration of such patents. As with any litigation, there can be no assurance of the outcomes, which, if adverse, could result in significantly shortened periods of exclusivity for these products and, with respect to products acquired through acquisitions accounted for as business combinations, potentially significant intangible asset impairment charges. Bridion — As previously disclosed, between January and November 2020, the Company received multiple Paragraph IV Certification Letters under the Hatch-Waxman Act notifying the Company that generic drug companies had filed applications to the FDA seeking pre-patent expiry approval to sell generic versions of Bridion (sugammadex) Injection. In March, April and December 2020, the Company filed patent infringement lawsuits in the U.S. District Courts for the District of New Jersey and the Northern District of West Virginia against those generic companies. All actions in the District of New Jersey were consolidated. The West Virginia case was jointly dismissed with prejudice in August 2022 in favor of proceeding in New Jersey. The remaining defendants in the New Jersey action stipulated to infringement of the asserted claims and withdrew all remaining claims and defenses other than a defense seeking to shorten the patent term extension (PTE) of the sugammadex patent to December 2022. As previously disclosed, in June 2023, the U.S. District Court for the District of New Jersey ruled in Merck’s favor. The court held that Merck’s calculation of PTE for the sugammadex patent covering the compound is not invalid and that the U.S. Patent & Trademark Office correctly granted a full five-year extension. This ruling affirms and validates Merck’s U.S. patent protection for Bridion through at least January 2026. Also in June 2023, the U.S. District Court for the District of New Jersey issued a final judgment prohibiting the FDA from approving any of the pending or tentatively approved generic applications until January 27, 2026, except for any subsequent agreements between defendants and Merck or further order by the court. In July 2023, defendants filed a notice of appeal with the U.S. Court of Appeals for the Federal Circuit. The appeal is currently pending. While the New Jersey action was pending, the Company settled with five generic companies providing that these generic companies can bring their generic versions of Bridion to the market in January 2026 (which may be delayed by any applicable pediatric exclusivity) or earlier under certain circumstances. The Company agreed to stay the lawsuit filed against two generic companies, which in exchange agreed to be bound by a judgment on the merits of the consolidated action in the District of New Jersey. One of the generic companies in the consolidated action requested dismissal of the action against it and the Company did not oppose this request, which was subsequently granted by the court. The Company does not expect this company to bring its generic version of Bridion to the market before January 2026 or later, depending on any applicable pediatric exclusivity. On February 5, 2024, the Company received another Paragraph IV Certification Letter under the Hatch-Waxman Act notifying the Company that Hikma Pharmaceuticals USA Inc. (Hikma) has filed an application to the FDA seeking pre-patent expiry approval to sell a generic version of Bridion Injection. On March 15, 2024, the Company filed a patent infringement lawsuit in the U.S. District Court for the District of New Jersey against Hikma, postponing FDA approval of the Hikma generic drug for 30 months or until expiration of the sugammadex patent (January 27, 2026) and any potentially applicable pediatric exclusivity or an adverse court decision, if any, whichever may occur earlier. Expiration of the patent, and any potentially applicable pediatric exclusivity, will occur earlier than expiry of the 30-month stay. On April 16, 2024, the district court stayed the case during the pendency of the Federal Circuit appeal. Januvia, Janumet, Janumet XR — As previously disclosed, the FDA granted pediatric exclusivity with respect to Januvia (sitagliptin), Janumet (sitagliptin/metformin HCI), and Janumet XR (sitagliptin and metformin HCl extended-release), which provides a further six months of exclusivity in the U.S. beyond the expiration of all patents listed in the FDA’s Orange Book. Adding this exclusivity to the term of the key patent protection extended exclusivity on these products to January 2023. However, Januvia , Janumet , and Janumet XR contain sitagliptin phosphate monohydrate and the Company has another patent covering certain phosphate salt and polymorphic forms of sitagliptin that expires in May 2027, including pediatric exclusivity (2027 salt/polymorph patent). As previously disclosed, beginning in 2019, a number of generic drug companies filed ANDAs seeking approval of generic forms of Januvia and Janumet along with paragraph IV certifications challenging the validity of the 2027 salt/polymorph patent. The Company responded by filing infringement suits which have all been settled. The Company has settled with a total of 26 generic companies providing that these generic companies can bring their generic versions of Januvia and Janumet to the market in the U.S. in May 2026 or earlier under certain circumstances, and their generic versions of Janumet XR to the market in July 2026 or earlier under certain circumstances. In March 2021, the Company filed a patent infringement lawsuit in the U.S. District Court for the District of Delaware against Zydus Worldwide DMCC, Zydus Pharmaceuticals (USA) Inc., and Cadila Healthcare Ltd. (collectively, Zydus). In that lawsuit, the Company alleged infringement of the 2027 salt/polymorph patent based on the filing of Zydus’s NDA seeking approval of a form of sitagliptin that is a different form than that used in Januvia . In December 2022, the parties reached settlement that included dismissal of the case without prejudice enabling Zydus to seek final approval of a non-automatically substitutable product. In January 2023, the Company received a Paragraph IV Certification Letter under the Hatch-Waxman Act notifying the Company that Zydus filed an ANDA seeking approval of sitagliptin/metformin HCl tablets and certifying that no valid or enforceable claim of any of the patents listed in FDA’s Orange Book for Janumet will be infringed by the proposed Zydus product. In March 2023, the parties reached settlement enabling Zydus to seek final approval of a non-automatically substitutable product containing a different form of sitagliptin than that used in Janumet. In November 2023, the Company received a Paragraph IV Certification Letter under the Hatch-Waxman Act notifying the Company that Zydus filed an ANDA seeking approval of sitagliptin/metformin HCl Extended Release tablets. In January 2024, the parties reached settlement enabling Zydus to seek final approval of a non-automatically substitutable version containing a different form of sitagliptin than that used in Janumet XR . As a result of these settlement agreements related to the later expiring 2027 salt/polymorph patent directed to the specific sitagliptin salt form of the products, the Company expects that Januvia and Janumet will not lose market exclusivity in the U.S. until May 2026 and Janumet XR will not lose market exclusivity in the U.S. until July 2026 , although Zydus has received FDA approval for a non-automatically substitutable form of sitagliptin that differs from the form in the Company’s sitagliptin products . Supplementary Protection Certificates (SPCs) for Janumet expired in April 2023 for the majority of European countries. Prior to expiration, generic companies sought revocation of the Janumet SPCs in a number of European countries. In February 2022, a Finnish court referred certain questions to the Court of Justice of the European Union (CJEU) that could determine the validity of the Janumet SPCs in Europe, for which an oral hearing was held in March 2023 and an Advocate General Opinion was received on June 6, 2024, with a decision expected later in 2024. If the CJEU renders a decision that negatively impacts the validity of the Janumet SPCs throughout Europe, generic companies that were prevented from launching products during the SPC period in certain European countries may have an action for damages. Those countries include Belgium, Czech Republic, Ireland, Finland, France, Slovakia and Switzerland. If the Janumet SPCs are ultimately upheld, the Company has reserved its rights related to the pursuit of damages for those countries where a generic launched prior to expiry of the Janumet SPC. In October 2023, the Company filed a patent infringement lawsuit against Sawai Pharmaceuticals Co., Ltd. and Medisa Shinyaku Co., Ltd (collectively, Defendants) in the Tokyo District Court seeking an injunction to stop the manufacture, sale and offer for sale of the Defendants’ sitagliptin dihydrogen phosphate product, while the Company’s patents and patent term extensions are in force. The lawsuit is in response to the Defendants’ application for marketing authorization to sell a generic sitagliptin dihydrogen phosphate product, in the anhydrate form, which was approved on August 15, 2023. Merck asserts that the Defendants’ activity infringes a patent term extension associated with Merck’s patent directed to the sitagliptin compound patent. Keytruda — As previously disclosed, in November 2022, the Company filed a complaint against The Johns Hopkins University (JHU) in the U.S. District Court of Maryland. This action concerns patents emerging from a joint research collaboration between Merck and JHU regarding the use of pembrolizumab, which Merck sells under the trade name Keytruda . Merck and JHU partnered to design and conduct a clinical study administering Keytruda to cancer patients having tumors that had the genetic biomarker known as microsatellite instability-high (MSI-H). After the conclusion of the study, JHU secured U.S. patents citing the joint research study. Merck alleges that JHU has breached the collaboration agreement by filing and obtaining these patents without informing or involving Merck and then licensing the patents to others. Merck therefore brought this action for breach of contract, declaratory judgment of noninfringement, and promissory estoppel. JHU answered the complaint in April and May 2023, denying Merck’s claims, and counterclaiming for willful infringement of nine issued U.S. patents, including a demand for damages. Between November 30, 2023, and March 13, 2024, the Company filed inter partes review (IPR) petitions with the United States Patent & Trademark Office Patent Trial and Appeal Board (PTAB), challenging the validity of all nine patents asserted in the case. On June 13, 2024, the PTAB instituted a review of one of the asserted patents. The additional IPR petitions and institution decisions are all still pending. On July 1, 2024, the District Court granted Merck’s motion to stay the case in its entirety pending the outcome of the PTAB proceeding. Lynparza — In December 2022, AstraZeneca Pharmaceuticals LP received a Paragraph IV Certification Letter under the Hatch-Waxman Act notifying AstraZeneca that Natco Pharma Limited (Natco) has filed an application to the FDA seeking pre-patent expiry approval to sell generic versions of Lynparza (olaparib) tablet. In February 2023, AstraZeneca and the Company filed a patent infringement lawsuit in the U.S. District Court for the District of New Jersey/Delaware against Natco. This lawsuit, which asserts one or more patents covering olaparib, automatically stays FDA approval of the generic application until June 2025 or until an adverse court decision, if any, whichever may occur earlier. In December 2023, AstraZeneca Pharmaceuticals LP received a second Paragraph IV Certification Letter under the Hatch-Waxman Act notifying AstraZeneca that Sandoz Inc. (Sandoz) has filed an application to the FDA seeking pre-patent expiry approval to sell generic versions of Lynparza (olaparib) tablet. In February 2024, AstraZeneca and the Company filed a patent infringement lawsuit in the U.S. District Court for the District of New Jersey against Sandoz. This lawsuit, which asserts one or more patents covering olaparib, automatically stays FDA approval of the generic application until June 2026 or until an adverse court decision, if any, whichever may occur earlier. In May 2024, AstraZeneca Pharmaceuticals LP received a third Paragraph IV Certification Letter under the Hatch-Waxman Act notifying AstraZeneca that Cipla USA, Inc. and Cipla Limited (collectively, Cipla) filed an application to the FDA seeking pre-patent expiry approval to sell generic versions of Lynparza (olaparib) tablet. In June 2024, AstraZeneca and the Company filed a patent infringement lawsuit in the U.S. District Court for the District of New Jersey against Cipla. This lawsuit, which asserts one or more patents covering olaparib, automatically stays FDA approval of the generic application until November 2026 or until an adverse court decision, if any, whichever may occur earlier. Other Litigation There are various other pending legal proceedings involving the Company, principally product liability and intellectual property lawsuits. While it is not feasible to predict the outcome of such proceedings, in the opinion of the Company, either the likelihood of loss is remote or any reasonably possible loss associated with the resolution of such proceedings is not expected to be material to the Company’s financial condition, results of operations or cash flows either individually or in the aggregate. Legal Defense Reserves Legal defense costs expected to be incurred in connection with a loss contingency are accrued when probable and reasonably estimable. Some of the significant factors considered in the review of these legal defense reserves are as follows: the actual costs incurred by the Company; the development of the Company’s legal defense strategy and structure in light of the scope of its litigation; the number of cases being brought against the Company; the costs and outcomes of completed trials; and the most current information regarding anticipated timing, progression, and related costs of pre-trial activities and trials in the associated litigation. The amount of legal defense reserves as of June 30, 2024 and December 31, 2023 of approximately $215 million and $210 million, respectively, represents the Company’s best estimate of the minimum amount of defense costs to be incurred in connection with its outstanding litigation; however, events such as additional trials and other events that could arise in the course of its litigation could affect the ultimate amount of legal defense costs to be incurred by the Company. The Company will continue to monitor its legal defense costs and review the adequacy of the associated reserves and may determine to increase the reserves at any time in the future if, based upon the factors set forth, it believes it would be appropriate to do so.

Equity

Equity	6 Months Ended
	Jun. 30, 2024
Equity [Abstract]
Equity	Equity Three Months Ended June 30, Common Stock Other Retained Accumulated Treasury Stock Non- Total ($ and shares in millions except per share amounts) Shares Par Value Shares Cost Balance at April 1, 2023 3,577 $ 1,788 $ 44,467 $ 62,039 $ (4,883) 1,040 $ (56,577) $ 71 $ 46,905 Net loss attributable to Merck & Co., Inc. — — — (5,975) — — — — (5,975) Other comprehensive loss, net of taxes — — — — (17) — — — (17) Cash dividends declared on common stock ($0.73 per share) — — — (1,866) — — — — (1,866) Treasury stock shares purchased — — — — — 3 (338) — (338) Share-based compensation plans and other — — (248) — — (5) 303 — 55 Net income attributable to noncontrolling interests — — — — — — — 3 3 Distributions attributable to noncontrolling interests — — — — — — — (25) (25) Balance at June 30, 2023 3,577 $ 1,788 $ 44,219 $ 54,198 $ (4,900) 1,038 $ (56,612) $ 49 $ 38,742 Balance at April 1, 2024 3,577 $ 1,788 $ 44,598 $ 56,697 $ (5,274) 1,044 $ (57,445) $ 60 $ 40,424 Net income attributable to Merck & Co., Inc. — — — 5,455 — — — — 5,455 Other comprehensive loss, net of taxes — — — — (87) — — — (87) Cash dividends declared on common stock ($0.77 per share) — — — (1,965) — — — — (1,965) Treasury stock shares purchased — — — — — 2 (251) — (251) Share-based compensation plans and other — — (236) — — (5) 302 — 66 Net income attributable to noncontrolling interests — — — — — — — 6 6 Balance at June 30, 2024 3,577 $ 1,788 $ 44,362 $ 60,187 $ (5,361) 1,041 $ (57,394) $ 66 $ 43,648 Six Months Ended June 30, Common Stock Other Retained Accumulated Treasury Stock Non- Total ($ and shares in millions except per share amounts) Shares Par Value Shares Cost Balance at January 1, 2023 3,577 $ 1,788 $ 44,379 $ 61,081 $ (4,768) 1,039 $ (56,489) $ 67 $ 46,058 Net loss attributable to Merck & Co., Inc. — — — (3,154) — — — — (3,154) Other comprehensive loss, net of taxes — — — — (132) — — — (132) Cash dividends declared on common stock ($1.46 per share) — — — (3,729) — — — — (3,729) Treasury stock shares purchased — — — — — 4 (487) — (487) Share-based compensation plans and other — — (160) — — (5) 364 — 204 Net income attributable to noncontrolling interests — — — — — — — 7 7 Distributions attributable to noncontrolling interests — — — — — — — (25) (25) Balance at June 30, 2023 3,577 $ 1,788 $ 44,219 $ 54,198 $ (4,900) 1,038 $ (56,612) $ 49 $ 38,742 Balance at January 1, 2024 3,577 $ 1,788 $ 44,509 $ 53,895 $ (5,161) 1,045 $ (57,450) $ 54 $ 37,635 Net income attributable to Merck & Co., Inc. — — — 10,217 — — — — 10,217 Other comprehensive loss, net of taxes — — — — (200) — — — (200) Cash dividends declared on common stock ($1.54 per share) — — — (3,925) — — — — (3,925) Treasury stock shares purchased — — — — — 3 (373) — (373) Share-based compensation plans and other — — (147) — — (7) 429 1 283 Net income attributable to noncontrolling interests — — — — — — — 11 11 Balance at June 30, 2024 3,577 $ 1,788 $ 44,362 $ 60,187 $ (5,361) 1,041 $ (57,394) $ 66 $ 43,648

Pension and Other Postretiremen

Pension and Other Postretirement Benefit Plans	6 Months Ended
	Jun. 30, 2024
Retirement Benefits [Abstract]
Pension and Other Postretirement Benefit Plans	Pension and Other Postretirement Benefit Plans The Company has defined benefit pension plans covering eligible employees in the U.S. and in certain of its international subsidiaries. The net periodic benefit cost (credit) of such plans consisted of the following components: Three Months Ended Six Months Ended 2024 2023 2024 2023 ($ in millions) U.S. International U.S. International U.S. International U.S. International Service cost $ 86 $ 60 $ 76 $ 50 $ 173 $ 122 $ 152 $ 99 Interest cost 134 73 133 75 269 147 266 149 Expected return on plan assets (207) (137) (185) (130) (417) (278) (372) (257) Amortization of unrecognized prior service (credit) cost — (3) — 16 — (6) (1) 12 Net loss (gain) amortization 10 1 — (1) 20 3 — (2) Termination benefits — — 1 — 4 — 1 — Curtailments — — 2 — — — 5 — Settlements — — 5 — — — 26 — $ 23 $ (6) $ 32 $ 10 $ 49 $ (12) $ 77 $ 1 The Company provides medical benefits, principally to its eligible U.S. retirees and similar benefits to their dependents, through its other postretirement benefit plans. The net credit of such plans consisted of the following components: Three Months Ended Six Months Ended ($ in millions) 2024 2023 2024 2023 Service cost $ 8 $ 8 $ 15 $ 17 Interest cost 14 16 28 31 Expected return on plan assets (20) (16) (40) (32) Amortization of unrecognized prior service credit (11) (12) (21) (25) Net gain amortization (12) (11) (24) (21) $ (21) $ (15) $ (42) $ (30) In connection with restructuring actions (see Note 4), termination charges were recorded on pension plans related to expanded eligibility for certain employees exiting Merck. Also, in connection with these restructuring activities, curtailments were recorded on certain pension plans. In addition, lump sum payments to U.S. pension plan participants triggered partial settlement charges in the second quarter and first six months of 2023. These partial settlements triggered remeasurements of some of the Company’s U.S. pension plans. Remeasurements during the first six months of 2023 resulted in a net increase of $47 million to net pension liabilities and also resulted in a related adjustment to AOCL . The components of net periodic benefit cost (credit) other than the service cost component are included in Other (income) expense, net (see Note 11), with the exception of certain amounts for termination benefits, curtailments and settlements, which are recorded in Restructuring costs if the event giving rise to the termination benefits, curtailment or settlement related to restructuring actions.

Other (Income) Expense, Net

Other (Income) Expense, Net	6 Months Ended
	Jun. 30, 2024
Other Income and Expenses [Abstract]
Other (Income) Expense, Net	Other (Income) Expense, Net Other (income) expense, net, consisted of: Three Months Ended Six Months Ended ($ in millions) 2024 2023 2024 2023 Interest income $ (69) $ (109) $ (141) $ (221) Interest expense 310 277 613 519 Exchange losses 60 62 144 122 (Income) loss from investments in equity securities, net (1) (56) 175 (200) (274) Net periodic defined benefit plan (credit) cost other than service cost (159) (111) (319) (226) Other, net (44) (122) (85) 339 $ 42 $ 172 $ 12 $ 259 (1) Includes net realized and unrealized gains and losses from investments in equity securities either owned directly or through ownership interests in investment funds. Unrealized gains and losses from investments that are directly owned are determined at the end of the reporting period, while gains and losses from ownership interests in investment funds are accounted for on a one quarter lag. Other, net (as reflected in the table above) in the first six months of 2023 includes a $572.5 million charge related to settlements with certain plaintiffs in the Zetia antitrust litigation. Interest paid for the six months ended June 30, 2024 and 2023 was $581 million and $449 million, respectively.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2024
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The effective income tax rates were 9.1% and 12.4% for the second quarter and first six months of 2024, respectively. The effective income tax rates in the second quarter and first six months of 2024 reflect a 4.3 percentage point favorable impact and a 2.2 percentage point favorable impact, respectively, due to a $259 million reduction in reserves for unrecognized income tax benefits resulting from the expiration in June 2024 of the statute of limitations for assessments related to the 2019 federal tax return year. The effective income tax rate for the first six months of 2024 also reflects a 0.7 percentage point unfavorable discrete impact of a charge for the acquisition of Harpoon for which no tax benefit was recognized. The income tax provision of $637 million and $1.5 billion for the second quarter and first six months of 2023, respectively, on pretax losses of $5.3 billion and $1.7 billion, respectively, resulted in effective income tax rates of (11.9)% and (86.8)%, respectively. The second quarter 2023 effective income tax rate includes the impact of a charge for the acquisition of Prometheus for which no tax benefit was recognized, which unfavorably affected the tax rate by 25.1 percentage points, as well as the favorable impact of net unrealized losses from investments in equity securities, which were taxed at the U.S. tax rate. The effective income tax rate for the first six months of 2023 includes a 101.9 percentage point combined unfavorable impact of charges for the acquisitions of Prometheus and Imago for which no tax benefits were recognized, as well as higher foreign taxes, the impact of the R&D capitalization provision of the Tax Cuts and Jobs Act of 2017 (TCJA) on the Company’s U.S. global intangible low-taxed income inclusion, and net unrealized gains from investments in equity securities, which were taxed at the U.S. tax rate, partially offset by higher foreign tax credits. The Internal Revenue Service (IRS) is currently conducting examinations of the Company’s tax returns for the years 2017 and 2018, including the one-time transition tax enacted under the TCJA. If the IRS disagrees with the Company’s transition tax position, it may result in a significant tax liability. The statute of limitations for assessments with respect to the 2019 federal tax return year expired in June 2024 as noted above. The statute of limitations for assessments with respect to the 2020 federal tax return year will expire in October of 2024, unless extended.

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2024
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share The calculations of earnings (loss) per share are as follows: Three Months Ended Six Months Ended ($ and shares in millions except per share amounts) 2024 2023 2024 2023 Net Income (Loss) Attributable to Merck & Co., Inc. $ 5,455 $ (5,975) $ 10,217 $ (3,154) Average common shares outstanding 2,534 2,539 2,534 2,539 Common shares issuable (1) 10 — 10 — Average common shares outstanding assuming dilution 2,544 2,539 2,544 2,539 Basic Earnings (Loss) per Common Share Attributable to Merck & Co., Inc. Common Shareholders $ 2.15 $ (2.35) $ 4.03 $ (1.24) Earnings (Loss) per Common Share Assuming Dilution Attributable to Merck & Co., Inc. Common Shareholders $ 2.14 $ (2.35) $ 4.02 $ (1.24) (1) Issuable primarily under share-based compensation plans.

Other Comprehensive Income (Los

Other Comprehensive Income (Loss)	6 Months Ended
	Jun. 30, 2024
Equity [Abstract]
Other Comprehensive Income (Loss)	Other Comprehensive Income (Loss) Changes in each component of other comprehensive income (loss) are as follows: Three Months Ended June 30, ($ in millions) Derivatives Employee Foreign Currency Accumulated Other Balance April 1, 2023, net of taxes $ (60) $ (2,458) $ (2,365) $ (4,883) Other comprehensive income (loss) before reclassification adjustments, pretax 194 (6) (115) 73 Tax (41) 1 (22) (62) Other comprehensive income (loss) before reclassification adjustments, net of taxes 153 (5) (137) 11 Reclassification adjustments, pretax (11) (1) (23) (2) — (34) Tax 3 3 — 6 Reclassification adjustments, net of taxes (8) (20) — (28) Other comprehensive income (loss), net of taxes 145 (25) (137) (17) Balance June 30, 2023, net of taxes $ 85 $ (2,483) $ (2,502) $ (4,900) Balance April 1, 2024, net of taxes $ 106 $ (2,798) $ (2,582) $ (5,274) Other comprehensive income (loss) before reclassification adjustments, pretax 139 1 (157) (17) Tax (29) 2 (7) (34) Other comprehensive income (loss) before reclassification adjustments, net of taxes 110 3 (164) (51) Reclassification adjustments, pretax (55) (1) (15) (2) 20 (50) Tax 12 2 — 14 Reclassification adjustments, net of taxes (43) (13) 20 (36) Other comprehensive income (loss), net of taxes 67 (10) (144) (87) Balance June 30, 2024, net of taxes $ 173 $ (2,808) $ (2,726) $ (5,361) Six Months Ended June 30, ($ in millions) Derivatives Employee Foreign Currency Accumulated Other Balance January 1, 2023, net of taxes $ 73 $ (2,408) $ (2,433) $ (4,768) Other comprehensive income (loss) before reclassification adjustments, pretax 128 (53) (36) 39 Tax (27) 3 (42) (66) Other comprehensive income (loss) before reclassification adjustments, net of taxes 101 (50) (78) (27) Reclassification adjustments, pretax (113) (1) (30) (2) 9 (134) Tax 24 5 — 29 Reclassification adjustments, net of taxes (89) (25) 9 (105) Other comprehensive income (loss), net of taxes 12 (75) (69) (132) Balance June 30, 2023, net of taxes $ 85 $ (2,483) $ (2,502) $ (4,900) Balance January 1, 2024, net of taxes $ (24) $ (2,793) $ (2,344) $ (5,161) Other comprehensive income (loss) before reclassification adjustments, pretax 348 6 (382) (28) Tax (73) (2) (20) (95) Other comprehensive income (loss) before reclassification adjustments, net of taxes 275 4 (402) (123) Reclassification adjustments, pretax (99) (1) (30) (2) 20 (109) Tax 21 11 — 32 Reclassification adjustments, net of taxes (78) (19) 20 (77) Other comprehensive income (loss), net of taxes 197 (15) (382) (200) Balance June 30, 2024, net of taxes $ 173 $ (2,808) $ (2,726) $ (5,361) (1) Primarily relates to foreign currency cash flow hedges that were reclassified from AOCL to Sales . (2) Includes net amortization of prior service cost, actuarial gains and losses, settlements and curtailments included in net periodic benefit cost (see Note 10).

Segment Reporting

Segment Reporting	6 Months Ended
	Jun. 30, 2024
Segment Reporting [Abstract]
Segment Reporting	Segment Reporting The Company’s operations are principally managed on a product basis and include two operating segments, Pharmaceutical and Animal Health, both of which are reportable segments. The Pharmaceutical segment includes human health pharmaceutical and vaccine products. Human health pharmaceutical products consist of therapeutic and preventive agents, generally sold by prescription, for the treatment of human disorders. The Company sells these human health pharmaceutical products primarily to drug wholesalers and retailers, hospitals, government agencies and managed health care providers such as health maintenance organizations, pharmacy benefit managers and other institutions. Human health vaccine products consist of preventive pediatric, adolescent and adult vaccines. The Company sells these human health vaccines primarily to physicians, wholesalers, distributors and government entities. A large component of pediatric and adolescent vaccine sales are made to the U.S. Centers for Disease Control and Prevention Vaccines for Children program, which is funded by the U.S. government. Additionally, the Company sells vaccines to the Federal government for placement into vaccine stockpiles. The Animal Health segment discovers, develops, manufactures and markets a wide range of veterinary pharmaceutical and vaccine products, as well as health management solutions and services, for the prevention, treatment and control of disease in all major livestock and companion animal species. The Company also offers an extensive suite of digitally connected identification, traceability and monitoring products. The Company sells its products to veterinarians, distributors, animal producers, farmers and pet owners. Sales of the Company’s products were as follows: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 ($ in millions) U.S. Int’l Total U.S. Int’l Total U.S. Int’l Total U.S. Int’l Total Pharmaceutical: Oncology Keytruda $ 4,412 $ 2,858 $ 7,270 $ 3,863 $ 2,408 $ 6,271 $ 8,531 $ 5,686 $ 14,217 $ 7,348 $ 4,718 $ 12,065 Alliance revenue-Lynparza (1) 153 165 317 144 166 310 288 321 609 286 299 585 Alliance revenue-Lenvima (1) 177 73 249 163 79 242 349 155 504 316 158 474 Welireg 116 10 126 49 2 50 194 17 211 90 3 92 Alliance revenue-Reblozyl (2) 75 15 90 36 11 47 133 28 161 66 24 90 Vaccines Gardasil/Gardasil 9 536 1,941 2,478 464 1,994 2,458 1,024 3,702 4,727 880 3,550 4,430 ProQuad/M-M-R II /Varivax 490 127 617 447 135 582 928 259 1,187 868 242 1,109 Vaxneuvance 99 90 189 147 20 168 260 148 408 241 33 274 RotaTeq 107 56 163 93 37 131 257 123 379 273 155 428 Pneumovax 23 11 48 59 23 69 92 17 103 120 63 125 188 Hospital Acute Care Bridion 351 104 455 299 203 502 680 215 895 576 413 989 Prevymis 90 98 188 61 82 143 165 197 362 116 157 273 Dificid 79 12 92 68 8 76 147 17 165 130 11 141 Zerbaxa 33 28 62 30 24 54 67 51 118 57 47 104 Noxafil — 44 45 11 45 55 8 92 101 25 91 116 Cardiovascular Alliance revenue-Adempas/Verquvo (3) 98 8 106 70 (2) 68 188 16 203 153 14 167 Adempas — 72 72 — 65 65 — 142 142 — 125 125 Winrevair 70 — 70 — — — 70 — 70 — — — Virology Lagevrio 15 95 110 2 201 203 60 400 460 — 595 595 Isentress/Isentress HD 43 46 89 56 80 136 93 107 200 108 151 259 Delstrigo 14 45 60 13 37 50 26 89 116 24 70 94 Pifeltro 27 12 39 27 11 38 56 25 81 51 21 72 Neuroscience Belsomra 19 34 53 21 42 63 33 66 99 37 82 119 Immunology Simponi — 172 172 — 180 180 — 356 356 — 359 359 Remicade — 35 35 — 48 48 — 74 74 — 99 99 Diabetes Januvia 177 227 405 243 267 511 361 463 824 514 548 1,062 Janumet 17 208 224 82 272 354 55 420 475 138 544 683 Other pharmaceutical (4) 190 386 573 158 403 560 346 807 1,151 328 857 1,187 Total Pharmaceutical segment sales 7,399 7,009 14,408 6,570 6,887 13,457 14,336 14,079 28,415 12,688 13,491 26,179 Animal Health: Livestock 168 669 837 165 643 807 334 1,352 1,686 338 1,318 1,656 Companion Animal 287 358 645 310 339 649 595 712 1,307 618 673 1,291 Total Animal Health segment sales 455 1,027 1,482 475 982 1,456 929 2,064 2,993 956 1,991 2,947 Total segment sales 7,854 8,036 15,890 7,045 7,869 14,913 15,265 16,143 31,408 13,644 15,482 29,126 Other (5) 22 200 222 (27) 149 122 89 390 479 32 364 396 $ 7,876 $ 8,236 $ 16,112 $ 7,018 $ 8,018 $ 15,035 $ 15,354 $ 16,533 $ 31,887 $ 13,676 $ 15,846 $ 29,522 U.S. plus international may not equal total due to rounding. (1) Alliance revenue for Lynparza and Lenvima represents Merck’s share of profits, which are product sales net of cost of sales and commercialization costs (see Note 3). (2) Alliance revenue for Reblozyl represents royalties (see Note 3). (3) Alliance revenue for Adempas/Verquvo represents Merck’s share of profits from sales in Bayer’s marketing territories, which are product sales net of cost of sales and commercialization costs (see Note 3). (4) Other pharmaceutical primarily reflects sales of other human health pharmaceutical products, including products within the franchises not listed separately. (5) Other is primarily comprised of miscellaneous corporate revenue, including revenue hedging activities which increased sales by $118 million and $128 million for the six months ended June 30, 2024 and 2023, respectively, as well as revenue from third-party manufacturing arrangements (including sales to Organon). Other for the six months ended June 30, 2024 and 2023 also includes $76 million and $54 million, respectively, related to upfront and milestone payments received by Merck for out-licensing arrangements. Product sales are recorded net of the provision for discounts, including chargebacks, which are customer discounts that occur when a contracted customer purchases through an intermediary wholesale purchaser, and rebates that are owed based upon definitive contractual agreements or legal requirements with private sector and public sector (Medicaid and Medicare Part D) benefit providers, after the final dispensing of the product by a pharmacy to a benefit plan participant. These discounts, in the aggregate, reduced U.S. sales by $3.3 billion and $3.2 billion for the three months ended June 30, 2024 and 2023, respectively, and $6.6 billion and $6.3 billion for the six months ended June 30, 2024 and June 30, 2023, respectively. Consolidated sales by geographic area where derived are as follows: Three Months Ended Six Months Ended ($ in millions) 2024 2023 2024 2023 United States $ 7,876 $ 7,018 $ 15,354 $ 13,676 Europe, Middle East and Africa 3,515 3,348 7,078 6,651 China 1,817 1,913 3,589 3,628 Latin America 858 742 1,655 1,403 Japan 686 675 1,507 1,434 Asia Pacific (other than China and Japan) 748 848 1,472 1,694 Other 612 491 1,232 1,036 $ 16,112 $ 15,035 $ 31,887 $ 29,522 A reconciliation of segment profits to Income (Loss) Before Taxes is as follows: Three Months Ended Six Months Ended ($ in millions) 2024 2023 2024 2023 Segment profits: Pharmaceutical segment $ 11,200 $ 9,854 $ 22,104 $ 18,993 Animal Health segment 508 467 1,064 1,032 Total segment profits 11,708 10,321 23,168 20,025 Other profits 129 19 274 184 Unallocated: Interest income 69 109 141 221 Interest expense (310) (277) (613) (519) Amortization (614) (477) (1,087) (1,020) Depreciation (450) (376) (902) (775) Research and development (3,360) (13,194) (7,209) (17,341) Restructuring costs (80) (151) (202) (218) Charge for Zetia antitrust litigation settlements — — — (573) Other unallocated, net (1,086) (1,309) (1,895) (1,669) $ 6,006 $ (5,335) $ 11,675 $ (1,685) Pharmaceutical segment profits are comprised of segment sales less standard costs, as well as selling, general and administrative expenses directly incurred by the segment. Animal Health segment profits are comprised of segment sales, less all cost of sales, as well as selling, general and administrative expenses and research and development costs directly incurred by the segment. For internal management reporting presented to the chief operating decision maker, Merck does not allocate the remaining cost of sales not included in segment profits as described above, research and development expenses incurred by Merck Research Laboratories, the Company’s research and development division that focuses on human health-related activities, or general and administrative expenses not directly incurred by the segments, nor the cost of financing these activities. Separate divisions maintain responsibility for monitoring and managing these costs, including depreciation related to fixed assets utilized by these divisions and, therefore, they are not included in segment profits. In addition, costs related to restructuring activities, as well as the amortization of intangible assets and amortization of purchase accounting adjustments are not allocated to segments. Other profits are primarily comprised of miscellaneous corporate profits, as well as operating profits (losses) related to third-party manufacturing arrangements. Other unallocated, net, includes expenses from corporate and manufacturing cost centers, intangible asset impairment charges, gains or losses on sales of businesses, expense or income related to changes in the estimated fair value measurement of liabilities for contingent consideration, and other miscellaneous income or expense items.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Pay vs Performance Disclosure
Net Income (Loss) Attributable to Merck & Co., Inc.	$ 5,455	$ (5,975)	$ 10,217	$ (3,154)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Jun. 30, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Basis of Presentation (Policies

Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements of Merck & Co., Inc. (Merck or the Company) have been prepared pursuant to the rules and regulations for reporting on Form 10-Q. Accordingly, certain information and disclosures required by accounting principles generally accepted in the United States (U.S.) for complete consolidated financial statements are not included herein. These interim statements should be read in conjunction with the audited financial statements and notes thereto included in Merck’s Form 10-K filed on February 26, 2024.
Reclassifications	Certain reclassifications have been made to prior year amounts to conform to the current year presentation.
Recently Adopted Accounting Standard & Recently Issued Accounting Standards Not Yet Adopted	Recently Adopted Accounting Standard In August 2023, the Financial Accounting Standards Board (FASB) issued amended guidance that requires a newly formed joint venture to recognize and initially measure its assets and liabilities at fair value upon formation. The amended guidance includes exceptions to fair value measurement that are consistent with the accounting for business combinations guidance. The amended guidance is effective prospectively for all joint ventures with a formation date on or after January 1, 2025, however existing joint ventures have the option to apply the guidance retrospectively. The Company adopted the guidance effective July 1, 2024 on a prospective basis. There was no impact to the Company’s consolidated financial statements upon adoption. Recently Issued Accounting Standards Not Yet Adopted In November 2023, the FASB issued guidance intended to improve reportable segment disclosure requirements, primarily through expanded disclosures for significant segment expenses. The guidance is effective for annual periods beginning in 2024, and interim periods beginning in 2025. The guidance will result in incremental disclosures within the footnotes to the Company’s financial statements.
Legal Costs	Legal defense costs expected to be incurred in connection with a loss contingency are accrued when probable and reasonably estimable.

Collaborative Arrangements (Tab

Collaborative Arrangements (Tables)	6 Months Ended
	Jun. 30, 2024
Collaborative Arrangements [Abstract]
Collaboration Arrangements	Summarized financial information related to this collaboration is as follows: Three Months Ended Six Months Ended ($ in millions) 2024 2023 2024 2023 Alliance revenue - Lynparza $ 317 $ 310 $ 609 $ 585 Alliance revenue - Koselugo 37 25 75 48 Total alliance revenue $ 354 $ 335 $ 684 $ 633 Cost of sales (1) 82 78 163 148 Selling, general and administrative 43 51 82 98 Research and development 18 22 38 43 ($ in millions) June 30, 2024 December 31, 2023 Receivables from AstraZeneca included in Other current assets $ 349 $ 341 Payables to AstraZeneca included in Accrued and other current liabilities (2) 615 256 Payables to AstraZeneca included in Other Noncurrent Liabilities (2) — 600 (1) Represents amortization of capitalized milestone payments. (2) Includes accrued milestone payments. Summarized financial information related to this collaboration is as follows: Three Months Ended Six Months Ended ($ in millions) 2024 2023 2024 2023 Alliance revenue - Lenvima $ 249 $ 242 $ 504 $ 474 Cost of sales (1) 60 57 121 183 Selling, general and administrative 41 48 80 99 Research and development 6 17 13 56 ($ in millions) June 30, 2024 December 31, 2023 Receivables from Eisai included in Other current assets $ 245 $ 226 Payables to Eisai included in Accrued and other current liabilities (2) — 125 (1) Represents amortization of capitalized milestone payments. Amount in the first six months of 2023 includes $72 million of cumulative amortization catch-up expense as noted above. (2) Represents an accrued milestone payment. Summarized financial information related to this collaboration is as follows: Three Months Ended Six Months Ended ($ in millions) 2024 2023 2024 2023 Alliance revenue - Adempas/Verquvo $ 106 $ 68 $ 203 $ 167 Net sales of Adempas recorded by Merck 72 65 142 125 Net sales of Verquvo recorded by Merck 9 9 16 16 Total sales $ 187 $ 142 $ 361 $ 308 Cost of sales (1) 61 56 123 113 Selling, general and administrative 26 34 59 67 Research and development 28 25 55 50 ($ in millions) June 30, 2024 December 31, 2023 Receivables from Bayer included in Other current assets $ 170 $ 156 Payables to Bayer included in Accrued and other current liabilities 81 80 (1) Includes amortization of intangible assets, cost of products sold by Merck, as well as Bayer’s share of profits from sales in Merck’s marketing territories. Summarized financial information related to this collaboration is as follows: Three Months Ended Six Months Ended ($ in millions) 2024 2023 2024 2023 Net sales of Lagevrio recorded by Merck $ 110 $ 203 $ 460 $ 595 Cost of sales (1) 96 193 287 414 Selling, general and administrative 16 24 32 51 Research and development 7 10 2 26 ($ in millions) June 30, 2024 December 31, 2023 Receivables from Ridgeback included in Other current assets $ 8 $ — Payables to Ridgeback included in Accrued and other current liabilities (2) 24 113 (1) Includes cost of products sold by Merck, Ridgeback’s share of profits, royalty expense, amortization of capitalized milestone payments and inventory reserves. (2) Includes accrued royalties. Summarized financial information related to this collaboration is as follows: Three Months Ended Six Months Ended ($ in millions) 2024 2023 2024 2023 Selling, general and administrative $ 14 $ — $ 16 $ — Research and development 65 — 133 — ($ in millions) June 30, 2024 December 31, 2023 Payables to Daiichi Sankyo included in Accrued and other current liabilities $ 801 $ 800 Payables to Daiichi Sankyo included in Other Noncurrent Liabilities 750 750 Summarized financial information related to this collaboration is as follows: Three Months Ended Six Months Ended ($ in millions) 2024 2023 2024 2023 Selling, general and administrative $ 4 $ 1 $ 6 $ 2 Research and development 93 60 162 86 ($ in millions) June 30, 2024 December 31, 2023 Payables to Moderna included in Accrued and other current liabilities $ 73 $ 63

Restructuring (Tables)

Restructuring (Tables)	6 Months Ended
	Jun. 30, 2024
Restructuring and Related Activities [Abstract]
Charges Related to Restructuring Program Activities by Type of Cost	The following tables summarize the charges related to the restructuring programs by type of cost: Three Months Ended June 30, 2024 Six Months Ended June 30, 2024 ($ in millions) Accelerated Depreciation Separation Costs Other Exit Costs Total Accelerated Depreciation Separation Costs Other Total 2024 Restructuring Program Cost of sales $ 66 $ — $ — $ 66 $ 131 $ — $ 51 $ 182 Selling, general and administrative — — 31 31 — — 36 36 Research and development — — — — — — 2 2 Restructuring costs — 19 61 80 — 111 91 202 $ 66 $ 19 $ 92 $ 177 $ 131 $ 111 $ 180 $ 422 Three Months Ended June 30, 2023 Six Months Ended June 30, 2023 ($ in millions) Accelerated Depreciation Separation Costs Other Exit Costs Total Accelerated Depreciation Separation Costs Other Total 2019 Restructuring Program Cost of sales $ 22 $ — $ 10 $ 32 $ 43 $ — $ 18 $ 61 Selling, general and administrative — — 52 52 — — 53 53 Research and development — — 1 1 — — 1 1 Restructuring costs — 110 41 151 — 151 67 218 $ 22 $ 110 $ 104 $ 236 $ 43 $ 151 $ 139 $ 333
Charges and Spending Relating to Restructuring Activities by Program	The following table summarizes the charges and spending relating to restructuring program activities for the six months ended June 30, 2024: ($ in millions) Accelerated Depreciation Separation Costs Other Exit Costs Total Restructuring reserves January 1, 2024 $ — $ 681 $ 31 $ 712 Expenses 131 111 180 422 (Payments) receipts, net — (132) (73) (205) Non-cash activity (131) — (111) (242) Restructuring reserves June 30, 2024 $ — $ 660 $ 27 $ 687

Financial Instruments (Tables)

Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2024
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Effect of Net Investment Hedges on OCI and the Consolidated Statement of Operations	The effects of the Company’s net investment hedges on OCI and the Condensed Consolidated Statement of Income are shown below: Amount of Pretax (Gain) Loss Recognized in Other Comprehensive Income (1) Amount of Pretax Loss Recognized in Other (income) expense, net for Amounts Excluded from Effectiveness Testing Three Months Ended June 30, Six Months Ended June 30, Three Months Ended June 30, Six Months Ended June 30, ($ in millions) 2024 2023 2024 2023 2024 2023 2024 2023 Net Investment Hedging Relationships Foreign exchange contracts $ 5 $ — $ 3 $ 1 $ (1) $ — $ (1) $ 1 Euro-denominated notes (34) 21 (96) 73 — — — — (1) No amounts were reclassified from AOCL into income related to the sale of a subsidiary.
Summary of Interest Rate Swaps Held	At June 30, 2024, the Company was a party to six pay-floating, receive-fixed interest rate swap contracts designated as fair value hedges of a portion of fixed-rate notes as detailed in the table below. June 30, 2024 ($ in millions) Par Value of Debt Number of Interest Rate Swaps Held Total Swap Notional Amount 4.50% notes due 2033 $ 1,500 6 $ 1,500
Amounts Recorded on Balance Sheet Related to Fair Value Hedges	The table below presents the location of amounts recorded in the Condensed Consolidated Balance Sheet related to cumulative basis adjustments for fair value hedges: Carrying Amount of Hedged Liabilities Cumulative Amount of Fair Value Hedging Adjustment Increase Included in the Carrying Amount ($ in millions) June 30, 2024 December 31, 2023 June 30, 2024 December 31, 2023 Balance Sheet Caption Long-Term Debt $ 1,521 $ 1,056 $ 30 $ 56
Fair Value of Derivatives on a Gross Basis Segregated between those Derivatives that are Designated as Hedging Instruments and those that are Not Designated as Hedging Instruments	Presented in the table below is the fair value of derivatives on a gross basis segregated between those derivatives that are designated as hedging instruments and those that are not designated as hedging instruments: June 30, 2024 December 31, 2023 Fair Value of Derivative U.S. Dollar Fair Value of Derivative U.S. Dollar ($ in millions) Asset Liability Asset Liability Derivatives Designated as Hedging Instruments Balance Sheet Caption Interest rate swap contracts Other Assets $ 30 $ — $ 1,500 $ 57 $ — $ 1,000 Foreign exchange contracts Other current assets 226 — 8,830 106 — 6,138 Foreign exchange contracts Other Assets 46 — 2,052 26 — 1,929 Foreign exchange contracts Accrued and other current liabilities — 4 901 — 76 3,680 Foreign exchange contracts Other Noncurrent Liabilities — 1 230 — 1 7 302 5 13,513 189 77 12,754 Derivatives Not Designated as Hedging Instruments Balance Sheet Caption Foreign exchange contracts Other current assets 187 — 8,723 153 — 9,693 Foreign exchange contracts Other Assets 2 — 22 — — — Foreign exchange contracts Accrued and other current liabilities — 135 10,818 — 162 8,104 Foreign exchange contracts Other Noncurrent Liabilities — 2 22 — — — 189 137 19,585 153 162 17,797 $ 491 $ 142 $ 33,098 $ 342 $ 239 $ 30,551
Information on Derivative Positions Subject to Master Netting Arrangements as if they were Presented on a Net Basis	The following table provides information on the Company’s derivative positions subject to these master netting arrangements as if they were presented on a net basis, allowing for the right of offset by counterparty and cash collateral exchanged per the master agreements and related credit support annexes: June 30, 2024 December 31, 2023 ($ in millions) Asset Liability Asset Liability Gross amounts recognized in the condensed consolidated balance sheet $ 491 $ 142 $ 342 $ 239 Gross amounts subject to offset in master netting arrangements not offset in the condensed consolidated balance sheet (114) (114) (215) (215) Cash collateral received (123) — (3) — Net amounts $ 254 $ 28 $ 124 $ 24
Location and Amount of Pretax Gains and Losses of Derivatives	The table below provides information regarding the location and amount of pretax gains and losses of derivatives designated in fair value or cash flow hedging relationships: Three Months Ended June 30, Six Months Ended June 30, ($ in millions) 2024 2023 2024 2023 2024 2023 2024 2023 2024 2023 2024 2023 Financial Statement Caption in which Effects of Fair Value or Cash Flow Sales Other (income) expense, net (1) Other comprehensive income (loss) Sales Other (income) expense, net (1) Other comprehensive income (loss) $ 16,112 $ 15,035 $ 42 $ 172 $ (87) $ (17) $ 31,887 $ 29,522 $ 12 $ 259 $ (200) $ (132) (Gain) loss on fair value hedging relationships: Interest rate swap contracts Hedged items — — 4 — — — — — (26) — — — Derivatives designated as hedging instruments — — (4) — — — — — 27 — — — Impact of cash flow hedging relationships: Foreign exchange contracts Amount of gain recognized in OCI on derivatives — — — — 139 194 — — — — 348 128 Increase in Sales as a result of AOCL reclassifications 54 24 — — (54) (24) 98 125 — — (98) (125) Interest rate contracts Amount of gain recognized in Other (income) expense, net on derivatives — — — — — — — — (1) (1) — — Amount of gain recognized in OCI on derivatives — — — — — 13 — — — — (1) 13 (1) Interest expense is a component of Other (income) expense, net.
Income Statement Effects of Derivatives Not Designated as Hedging Instruments	The table below provides information regarding the income statement effects of derivatives not designated as hedging instruments: Amount of Derivative Pretax (Gain) Loss Recognized in Income Three Months Ended June 30, Six Months Ended June 30, ($ in millions) 2024 2023 2024 2023 Derivatives Not Designated as Hedging Instruments Income Statement Caption Foreign exchange contracts (1) Other (income) expense, net $ 9 $ (41) $ 75 $ (28) Foreign exchange contracts (2) Sales (10) (5) (20) (3) (1) These derivative contracts primarily mitigate changes in the value of remeasured foreign currency denominated monetary assets and liabilities attributable to changes in foreign currency exchange rates. (2) These derivative contracts serve as economic hedges of forecasted transactions .
Information on Investments in Debt and Equity Securities	Information on investments in debt and equity securities is as follows: June 30, 2024 December 31, 2023 Amortized Gross Unrealized Fair Amortized Gross Unrealized Fair ($ in millions) Gains Losses Gains Losses U.S. government and agency securities $ 77 $ — $ — $ 77 $ 72 $ — $ — $ 72 Commercial paper 50 — — 50 252 — — 252 Corporate notes and bonds — — — — 13 — — 13 Total debt securities $ 127 $ — $ — $ 127 $ 337 $ — $ — $ 337 Publicly traded equity securities (1) 1,026 764 Total debt and publicly traded equity securities $ 1,153 $ 1,101 (1) Unrealized net losses (gains) of $8 million and $(125) million were recorded in Other (income) expense, net in the second quarter and first six months of 2024, respectively, on equity securities still held at June 30, 2024. Unrealized net losses (gains) of $71 million and $(267) million were recorded in Other (income) expense, net in the second quarter and first six months of 2023, respectively, on equity securities still held at June 30, 2023.
Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis	Financial assets and liabilities measured at fair value on a recurring basis are summarized below: Fair Value Measurements Using Fair Value Measurements Using Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total ($ in millions) June 30, 2024 December 31, 2023 Assets Investments Commercial paper $ — $ 50 $ — $ 50 $ — $ 252 $ — $ 252 Publicly traded equity securities 357 — — 357 252 — — 252 357 50 — 407 252 252 — 504 Other assets (1) U.S. government and agency securities 77 — — 77 72 — — 72 Corporate notes and bonds — — — — 13 — — 13 Publicly traded equity securities (2) 669 — — 669 512 — — 512 746 — — 746 597 — — 597 Derivative assets (3) Forward exchange contracts — 278 — 278 — 202 — 202 Purchased currency options — 183 — 183 — 83 — 83 Interest rate swaps — 30 — 30 — 57 — 57 — 491 — 491 — 342 — 342 Total assets $ 1,103 $ 541 $ — $ 1,644 $ 849 $ 594 $ — $ 1,443 Liabilities Other liabilities Contingent consideration $ — $ — $ 225 $ 225 $ — $ — $ 354 $ 354 Derivative liabilities (3) Forward exchange contracts — 115 — 115 — 239 — 239 Written currency options — 27 — 27 — — — — — 142 — 142 — 239 — 239 Total liabilities $ — $ 142 $ 225 $ 367 $ — $ 239 $ 354 $ 593 (1) Investments included in other assets are restricted as to use, including for the payment of benefits under employee benefit plans. (2) Balance at June 30, 2024 includes securities with a fair value of $285 million, which were subject to a contractual sale restriction that expired in July 2024. (3) The fair value determination of derivatives includes the impact of the credit risk of counterparties to the derivatives and the Company’s own credit risk, the effects of which were not significant.
Information About the Changes in Liabilities for Contingent Consideration	Summarized information about the changes in the fair value of liabilities for contingent consideration associated with business combinations is as follows: ($ in millions) 2024 2023 Fair value January 1 $ 354 $ 456 Changes in estimated fair value (1) (3) 10 Payments (126) (117) Fair value June 30 (2) $ 225 $ 349 (1) Recorded in Cost of sales, Research and development expenses, and Other (income) expense, net . Includes cumulative translation adjustments. (2) Balance at June 30, 2024, includes $131 million of current liabilities, all of which relate to the termination of the Sanofi Pasteur MSD joint venture in 2016. As part of the termination, Merck recorded a liability for contingent future royalty payments of 11.5% on net sales of all Merck products that were previously sold by the joint venture through December 31, 2024. The fair value of this liability is determined utilizing the estimated amount and timing of projected cash flows using a risk-adjusted discount rate to present value the cash flows.

Inventories (Tables)

Inventories (Tables)	6 Months Ended
	Jun. 30, 2024
Inventory Disclosure [Abstract]
Inventory, current	Inventories consisted of: ($ in millions) June 30, 2024 December 31, 2023 Finished goods $ 1,889 $ 1,954 Raw materials and work in process 8,456 8,037 Supplies 267 277 Total 10,612 10,268 Decrease to LIFO cost (687) (562) $ 9,925 $ 9,706 Recognized as: Inventories $ 6,469 $ 6,358 Other Assets 3,456 3,348
Inventory, noncurrent	Inventories consisted of: ($ in millions) June 30, 2024 December 31, 2023 Finished goods $ 1,889 $ 1,954 Raw materials and work in process 8,456 8,037 Supplies 267 277 Total 10,612 10,268 Decrease to LIFO cost (687) (562) $ 9,925 $ 9,706 Recognized as: Inventories $ 6,469 $ 6,358 Other Assets 3,456 3,348

Equity (Tables)

Equity (Tables)	6 Months Ended
	Jun. 30, 2024
Equity [Abstract]
Schedule of Equity	Three Months Ended June 30, Common Stock Other Retained Accumulated Treasury Stock Non- Total ($ and shares in millions except per share amounts) Shares Par Value Shares Cost Balance at April 1, 2023 3,577 $ 1,788 $ 44,467 $ 62,039 $ (4,883) 1,040 $ (56,577) $ 71 $ 46,905 Net loss attributable to Merck & Co., Inc. — — — (5,975) — — — — (5,975) Other comprehensive loss, net of taxes — — — — (17) — — — (17) Cash dividends declared on common stock ($0.73 per share) — — — (1,866) — — — — (1,866) Treasury stock shares purchased — — — — — 3 (338) — (338) Share-based compensation plans and other — — (248) — — (5) 303 — 55 Net income attributable to noncontrolling interests — — — — — — — 3 3 Distributions attributable to noncontrolling interests — — — — — — — (25) (25) Balance at June 30, 2023 3,577 $ 1,788 $ 44,219 $ 54,198 $ (4,900) 1,038 $ (56,612) $ 49 $ 38,742 Balance at April 1, 2024 3,577 $ 1,788 $ 44,598 $ 56,697 $ (5,274) 1,044 $ (57,445) $ 60 $ 40,424 Net income attributable to Merck & Co., Inc. — — — 5,455 — — — — 5,455 Other comprehensive loss, net of taxes — — — — (87) — — — (87) Cash dividends declared on common stock ($0.77 per share) — — — (1,965) — — — — (1,965) Treasury stock shares purchased — — — — — 2 (251) — (251) Share-based compensation plans and other — — (236) — — (5) 302 — 66 Net income attributable to noncontrolling interests — — — — — — — 6 6 Balance at June 30, 2024 3,577 $ 1,788 $ 44,362 $ 60,187 $ (5,361) 1,041 $ (57,394) $ 66 $ 43,648 Six Months Ended June 30, Common Stock Other Retained Accumulated Treasury Stock Non- Total ($ and shares in millions except per share amounts) Shares Par Value Shares Cost Balance at January 1, 2023 3,577 $ 1,788 $ 44,379 $ 61,081 $ (4,768) 1,039 $ (56,489) $ 67 $ 46,058 Net loss attributable to Merck & Co., Inc. — — — (3,154) — — — — (3,154) Other comprehensive loss, net of taxes — — — — (132) — — — (132) Cash dividends declared on common stock ($1.46 per share) — — — (3,729) — — — — (3,729) Treasury stock shares purchased — — — — — 4 (487) — (487) Share-based compensation plans and other — — (160) — — (5) 364 — 204 Net income attributable to noncontrolling interests — — — — — — — 7 7 Distributions attributable to noncontrolling interests — — — — — — — (25) (25) Balance at June 30, 2023 3,577 $ 1,788 $ 44,219 $ 54,198 $ (4,900) 1,038 $ (56,612) $ 49 $ 38,742 Balance at January 1, 2024 3,577 $ 1,788 $ 44,509 $ 53,895 $ (5,161) 1,045 $ (57,450) $ 54 $ 37,635 Net income attributable to Merck & Co., Inc. — — — 10,217 — — — — 10,217 Other comprehensive loss, net of taxes — — — — (200) — — — (200) Cash dividends declared on common stock ($1.54 per share) — — — (3,925) — — — — (3,925) Treasury stock shares purchased — — — — — 3 (373) — (373) Share-based compensation plans and other — — (147) — — (7) 429 1 283 Net income attributable to noncontrolling interests — — — — — — — 11 11 Balance at June 30, 2024 3,577 $ 1,788 $ 44,362 $ 60,187 $ (5,361) 1,041 $ (57,394) $ 66 $ 43,648

Pension and Other Postretirem_2

Pension and Other Postretirement Benefit Plans (Tables)	6 Months Ended
	Jun. 30, 2024
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Net Benefit Costs	The Company has defined benefit pension plans covering eligible employees in the U.S. and in certain of its international subsidiaries. The net periodic benefit cost (credit) of such plans consisted of the following components: Three Months Ended Six Months Ended 2024 2023 2024 2023 ($ in millions) U.S. International U.S. International U.S. International U.S. International Service cost $ 86 $ 60 $ 76 $ 50 $ 173 $ 122 $ 152 $ 99 Interest cost 134 73 133 75 269 147 266 149 Expected return on plan assets (207) (137) (185) (130) (417) (278) (372) (257) Amortization of unrecognized prior service (credit) cost — (3) — 16 — (6) (1) 12 Net loss (gain) amortization 10 1 — (1) 20 3 — (2) Termination benefits — — 1 — 4 — 1 — Curtailments — — 2 — — — 5 — Settlements — — 5 — — — 26 — $ 23 $ (6) $ 32 $ 10 $ 49 $ (12) $ 77 $ 1
Other Postretirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Net Benefit Costs	The Company provides medical benefits, principally to its eligible U.S. retirees and similar benefits to their dependents, through its other postretirement benefit plans. The net credit of such plans consisted of the following components: Three Months Ended Six Months Ended ($ in millions) 2024 2023 2024 2023 Service cost $ 8 $ 8 $ 15 $ 17 Interest cost 14 16 28 31 Expected return on plan assets (20) (16) (40) (32) Amortization of unrecognized prior service credit (11) (12) (21) (25) Net gain amortization (12) (11) (24) (21) $ (21) $ (15) $ (42) $ (30)

Other (Income) Expense, Net (Ta

Other (Income) Expense, Net (Tables)	6 Months Ended
	Jun. 30, 2024
Other Income and Expenses [Abstract]
Other (Income) Expense, Net	Other (income) expense, net, consisted of: Three Months Ended Six Months Ended ($ in millions) 2024 2023 2024 2023 Interest income $ (69) $ (109) $ (141) $ (221) Interest expense 310 277 613 519 Exchange losses 60 62 144 122 (Income) loss from investments in equity securities, net (1) (56) 175 (200) (274) Net periodic defined benefit plan (credit) cost other than service cost (159) (111) (319) (226) Other, net (44) (122) (85) 339 $ 42 $ 172 $ 12 $ 259 (1)

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2024
Earnings Per Share [Abstract]
Calculations of Earnings Per Share	The calculations of earnings (loss) per share are as follows: Three Months Ended Six Months Ended ($ and shares in millions except per share amounts) 2024 2023 2024 2023 Net Income (Loss) Attributable to Merck & Co., Inc. $ 5,455 $ (5,975) $ 10,217 $ (3,154) Average common shares outstanding 2,534 2,539 2,534 2,539 Common shares issuable (1) 10 — 10 — Average common shares outstanding assuming dilution 2,544 2,539 2,544 2,539 Basic Earnings (Loss) per Common Share Attributable to Merck & Co., Inc. Common Shareholders $ 2.15 $ (2.35) $ 4.03 $ (1.24) Earnings (Loss) per Common Share Assuming Dilution Attributable to Merck & Co., Inc. Common Shareholders $ 2.14 $ (2.35) $ 4.02 $ (1.24) (1) Issuable primarily under share-based compensation plans.

Other Comprehensive Income (L_2

Other Comprehensive Income (Loss) (Tables)	6 Months Ended
	Jun. 30, 2024
Equity [Abstract]
Changes in AOCI by Component	Changes in each component of other comprehensive income (loss) are as follows: Three Months Ended June 30, ($ in millions) Derivatives Employee Foreign Currency Accumulated Other Balance April 1, 2023, net of taxes $ (60) $ (2,458) $ (2,365) $ (4,883) Other comprehensive income (loss) before reclassification adjustments, pretax 194 (6) (115) 73 Tax (41) 1 (22) (62) Other comprehensive income (loss) before reclassification adjustments, net of taxes 153 (5) (137) 11 Reclassification adjustments, pretax (11) (1) (23) (2) — (34) Tax 3 3 — 6 Reclassification adjustments, net of taxes (8) (20) — (28) Other comprehensive income (loss), net of taxes 145 (25) (137) (17) Balance June 30, 2023, net of taxes $ 85 $ (2,483) $ (2,502) $ (4,900) Balance April 1, 2024, net of taxes $ 106 $ (2,798) $ (2,582) $ (5,274) Other comprehensive income (loss) before reclassification adjustments, pretax 139 1 (157) (17) Tax (29) 2 (7) (34) Other comprehensive income (loss) before reclassification adjustments, net of taxes 110 3 (164) (51) Reclassification adjustments, pretax (55) (1) (15) (2) 20 (50) Tax 12 2 — 14 Reclassification adjustments, net of taxes (43) (13) 20 (36) Other comprehensive income (loss), net of taxes 67 (10) (144) (87) Balance June 30, 2024, net of taxes $ 173 $ (2,808) $ (2,726) $ (5,361) Six Months Ended June 30, ($ in millions) Derivatives Employee Foreign Currency Accumulated Other Balance January 1, 2023, net of taxes $ 73 $ (2,408) $ (2,433) $ (4,768) Other comprehensive income (loss) before reclassification adjustments, pretax 128 (53) (36) 39 Tax (27) 3 (42) (66) Other comprehensive income (loss) before reclassification adjustments, net of taxes 101 (50) (78) (27) Reclassification adjustments, pretax (113) (1) (30) (2) 9 (134) Tax 24 5 — 29 Reclassification adjustments, net of taxes (89) (25) 9 (105) Other comprehensive income (loss), net of taxes 12 (75) (69) (132) Balance June 30, 2023, net of taxes $ 85 $ (2,483) $ (2,502) $ (4,900) Balance January 1, 2024, net of taxes $ (24) $ (2,793) $ (2,344) $ (5,161) Other comprehensive income (loss) before reclassification adjustments, pretax 348 6 (382) (28) Tax (73) (2) (20) (95) Other comprehensive income (loss) before reclassification adjustments, net of taxes 275 4 (402) (123) Reclassification adjustments, pretax (99) (1) (30) (2) 20 (109) Tax 21 11 — 32 Reclassification adjustments, net of taxes (78) (19) 20 (77) Other comprehensive income (loss), net of taxes 197 (15) (382) (200) Balance June 30, 2024, net of taxes $ 173 $ (2,808) $ (2,726) $ (5,361) (1) Primarily relates to foreign currency cash flow hedges that were reclassified from AOCL to Sales . (2) Includes net amortization of prior service cost, actuarial gains and losses, settlements and curtailments included in net periodic benefit cost (see Note 10).

Segment Reporting (Tables)

Segment Reporting (Tables)	6 Months Ended
	Jun. 30, 2024
Segment Reporting [Abstract]
Sales from Products	Sales of the Company’s products were as follows: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 ($ in millions) U.S. Int’l Total U.S. Int’l Total U.S. Int’l Total U.S. Int’l Total Pharmaceutical: Oncology Keytruda $ 4,412 $ 2,858 $ 7,270 $ 3,863 $ 2,408 $ 6,271 $ 8,531 $ 5,686 $ 14,217 $ 7,348 $ 4,718 $ 12,065 Alliance revenue-Lynparza (1) 153 165 317 144 166 310 288 321 609 286 299 585 Alliance revenue-Lenvima (1) 177 73 249 163 79 242 349 155 504 316 158 474 Welireg 116 10 126 49 2 50 194 17 211 90 3 92 Alliance revenue-Reblozyl (2) 75 15 90 36 11 47 133 28 161 66 24 90 Vaccines Gardasil/Gardasil 9 536 1,941 2,478 464 1,994 2,458 1,024 3,702 4,727 880 3,550 4,430 ProQuad/M-M-R II /Varivax 490 127 617 447 135 582 928 259 1,187 868 242 1,109 Vaxneuvance 99 90 189 147 20 168 260 148 408 241 33 274 RotaTeq 107 56 163 93 37 131 257 123 379 273 155 428 Pneumovax 23 11 48 59 23 69 92 17 103 120 63 125 188 Hospital Acute Care Bridion 351 104 455 299 203 502 680 215 895 576 413 989 Prevymis 90 98 188 61 82 143 165 197 362 116 157 273 Dificid 79 12 92 68 8 76 147 17 165 130 11 141 Zerbaxa 33 28 62 30 24 54 67 51 118 57 47 104 Noxafil — 44 45 11 45 55 8 92 101 25 91 116 Cardiovascular Alliance revenue-Adempas/Verquvo (3) 98 8 106 70 (2) 68 188 16 203 153 14 167 Adempas — 72 72 — 65 65 — 142 142 — 125 125 Winrevair 70 — 70 — — — 70 — 70 — — — Virology Lagevrio 15 95 110 2 201 203 60 400 460 — 595 595 Isentress/Isentress HD 43 46 89 56 80 136 93 107 200 108 151 259 Delstrigo 14 45 60 13 37 50 26 89 116 24 70 94 Pifeltro 27 12 39 27 11 38 56 25 81 51 21 72 Neuroscience Belsomra 19 34 53 21 42 63 33 66 99 37 82 119 Immunology Simponi — 172 172 — 180 180 — 356 356 — 359 359 Remicade — 35 35 — 48 48 — 74 74 — 99 99 Diabetes Januvia 177 227 405 243 267 511 361 463 824 514 548 1,062 Janumet 17 208 224 82 272 354 55 420 475 138 544 683 Other pharmaceutical (4) 190 386 573 158 403 560 346 807 1,151 328 857 1,187 Total Pharmaceutical segment sales 7,399 7,009 14,408 6,570 6,887 13,457 14,336 14,079 28,415 12,688 13,491 26,179 Animal Health: Livestock 168 669 837 165 643 807 334 1,352 1,686 338 1,318 1,656 Companion Animal 287 358 645 310 339 649 595 712 1,307 618 673 1,291 Total Animal Health segment sales 455 1,027 1,482 475 982 1,456 929 2,064 2,993 956 1,991 2,947 Total segment sales 7,854 8,036 15,890 7,045 7,869 14,913 15,265 16,143 31,408 13,644 15,482 29,126 Other (5) 22 200 222 (27) 149 122 89 390 479 32 364 396 $ 7,876 $ 8,236 $ 16,112 $ 7,018 $ 8,018 $ 15,035 $ 15,354 $ 16,533 $ 31,887 $ 13,676 $ 15,846 $ 29,522 U.S. plus international may not equal total due to rounding. (1) Alliance revenue for Lynparza and Lenvima represents Merck’s share of profits, which are product sales net of cost of sales and commercialization costs (see Note 3). (2) Alliance revenue for Reblozyl represents royalties (see Note 3). (3) Alliance revenue for Adempas/Verquvo represents Merck’s share of profits from sales in Bayer’s marketing territories, which are product sales net of cost of sales and commercialization costs (see Note 3). (4) Other pharmaceutical primarily reflects sales of other human health pharmaceutical products, including products within the franchises not listed separately. (5) Other is primarily comprised of miscellaneous corporate revenue, including revenue hedging activities which increased sales by $118 million and $128 million for the six months ended June 30, 2024 and 2023, respectively, as well as revenue from third-party manufacturing arrangements (including sales to Organon). Other for the six months ended June 30, 2024 and 2023 also includes $76 million and $54 million, respectively, related to upfront and milestone payments received by Merck for out-licensing arrangements.
Consolidated Sales by Geographic Area	Consolidated sales by geographic area where derived are as follows: Three Months Ended Six Months Ended ($ in millions) 2024 2023 2024 2023 United States $ 7,876 $ 7,018 $ 15,354 $ 13,676 Europe, Middle East and Africa 3,515 3,348 7,078 6,651 China 1,817 1,913 3,589 3,628 Latin America 858 742 1,655 1,403 Japan 686 675 1,507 1,434 Asia Pacific (other than China and Japan) 748 848 1,472 1,694 Other 612 491 1,232 1,036 $ 16,112 $ 15,035 $ 31,887 $ 29,522
Reconciliation of Segment Profits to Income before Taxes	A reconciliation of segment profits to Income (Loss) Before Taxes is as follows: Three Months Ended Six Months Ended ($ in millions) 2024 2023 2024 2023 Segment profits: Pharmaceutical segment $ 11,200 $ 9,854 $ 22,104 $ 18,993 Animal Health segment 508 467 1,064 1,032 Total segment profits 11,708 10,321 23,168 20,025 Other profits 129 19 274 184 Unallocated: Interest income 69 109 141 221 Interest expense (310) (277) (613) (519) Amortization (614) (477) (1,087) (1,020) Depreciation (450) (376) (902) (775) Research and development (3,360) (13,194) (7,209) (17,341) Restructuring costs (80) (151) (202) (218) Charge for Zetia antitrust litigation settlements — — — (573) Other unallocated, net (1,086) (1,309) (1,895) (1,669) $ 6,006 $ (5,335) $ 11,675 $ (1,685)

Acquisitions, Divestitures, R_2

Acquisitions, Divestitures, Research Collaborations and Licensing Agreements - Narrative (Details) $ in Millions		1 Months Ended				3 Months Ended			6 Months Ended
	Jun. 02, 2021	Jul. 31, 2024 USD ($) aqua_facility candidate	Mar. 31, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jan. 31, 2023 USD ($)	Sep. 30, 2024 USD ($)	Jun. 30, 2024 USD ($) jurisdiction	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) jurisdiction	Jun. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)	Oct. 31, 2023 USD ($) candidate	Feb. 28, 2023 candidate
Business Acquisition [Line Items]
Research and development							$ 3,500	$ 13,321	$ 7,492	$ 17,597
Sales							16,112	15,035	31,887	29,522
Cost of sales							3,745	4,024	7,285	7,951
Other current assets							8,740		8,740		$ 8,368
Accrued and other current liabilities							14,712		14,712		15,766
Related Party
Business Acquisition [Line Items]
Other current assets							557		557		632
Accrued and other current liabilities							102		102		$ 598
Manufacturing and Supply Agreements | Related Party
Business Acquisition [Line Items]
Sales							93	96	201	191
Cost of sales							$ 92	101	$ 202	208
Minimum | Manufacturing and Supply Agreements | Related Party
Business Acquisition [Line Items]
Period of continuing involvement after disposal	4 years
Maximum | Manufacturing and Supply Agreements | Related Party
Business Acquisition [Line Items]
Period of continuing involvement after disposal	10 years
Discontinued Operations, Disposed of by Means Other than Sale, Spinoff | Organon & Co.
Business Acquisition [Line Items]
Number of jurisdictions remaining | jurisdiction							1		1
Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Business Acquisition [Line Items]
Number of antibody drug conjugates obtained right and obligations | candidate													7
Upfront payment made to collaborative partner				$ 175				175		175
Number of antibody drug conjugates terminated with collaborative partner | candidate												2
Eligible future contingent development-related payments (up to)												$ 540
Eligible future contingent regulatory milestone payments (up to)												1,500
Eligible future contingent sales-based milestone payments (up to)												$ 3,100
Stock investment in counterparty					$ 100
Harpoon Therapeutics, Inc.
Business Acquisition [Line Items]
Consideration transferred, asset acquisition			$ 765
Research and development									$ 656
Asset acquisition, transaction costs			56
Net assets acquired			$ 165
Prometheus Biosciences, Inc.
Business Acquisition [Line Items]
Consideration transferred, asset acquisition				11,000
Research and development								$ 10,200		10,200
Net assets acquired				877
Consideration transferred, to settle share-based equity awards				1,200
Consideration transferred, to settle equity awards, unvested				700
Cash recorded for asset acquisition				368
Investments recorded for asset acquisition				296
Deferred tax assets recorded for asset acquisition				218
Other net liabilities recorded for asset acquisition				$ 5
Imago Bio Sciences, Inc.
Business Acquisition [Line Items]
Consideration transferred, asset acquisition					1,350
Research and development										$ 1,200
Asset acquisition, transaction costs					60
Net assets acquired					$ 219
Forecast | Eyebiotech Limited
Business Acquisition [Line Items]
Research and development						$ 1,300
Subsequent Event | Orion
Business Acquisition [Line Items]
Eligible future contingent development-related payments (up to)		$ 30
Eligible future contingent regulatory milestone payments (up to)		625
Eligible future contingent sales-based milestone payments (up to)		$ 975
Subsequent Event | Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Business Acquisition [Line Items]
Number of exercised license option antibody drug conjugates | candidate		1
Number of licensed antibody drug conjugates | candidate		3
Number of unexercised license option antibody drug conjugates | candidate		1
Payment resulting from the license option exercise		$ 38
Subsequent Event | Eyebiotech Limited
Business Acquisition [Line Items]
Consideration transferred, asset acquisition		1,300
Potential developmental, regulatory and commercial milestone payments		1,700
Elanco Animal Health Incorporated Aqua Business | Subsequent Event
Business Acquisition [Line Items]
Payment to acquire business		$ 1,300
Aqua manufacturing facilities | aqua_facility		2

Collaborative Arrangements - As

Collaborative Arrangements - AstraZeneca PLC - Narrative (Details) - Lynparza - USD ($)	6 Months Ended		12 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2022
Licenses and Other
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Finite-lived intangible assets	$ 1,300,000,000
AstraZeneca | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Probable contingent payments			$ 600,000,000
Liabilities			$ 600,000,000
Eligible future contingent sales-based milestone payments (up to)	2,100,000,000
Regulatory milestone payments	245,000,000	$ 105,000,000
Eligible future contingent regulatory milestone payments (up to)	$ 0

Collaborative Arrangements - _2

Collaborative Arrangements - AstraZeneca PLC (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Cost of sales	$ 3,745	$ 4,024	$ 7,285	$ 7,951
Selling, general and administrative	2,739	2,702	5,221	5,182
Research and development	3,500	13,321	7,492	17,597
Other current assets	38,205		38,205		$ 32,168
Accrued and other current liabilities	14,712		14,712		15,766
AstraZeneca | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue from collaborative arrangement	354	335	684	633
Cost of sales	82	78	163	148
Selling, general and administrative	43	51	82	98
Research and development	18	22	38	43
Other current assets	349		349		341
Accrued and other current liabilities	615		615		256
Other noncurrent liabilities	0		0		$ 600
AstraZeneca | Alliance revenue - Lynparza | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue from collaborative arrangement	317	310	609	585
AstraZeneca | Alliance revenue - Koselugo | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue from collaborative arrangement	$ 37	$ 25	$ 75	$ 48

Collaborative Arrangements - Ei

Collaborative Arrangements - Eisai Co., Ltd. - Narrative (Details) - USD ($)	3 Months Ended
	Sep. 30, 2023	Mar. 31, 2023	Jun. 30, 2024
Alliance revenue - Lenvima | Licenses and Other
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Finite-lived intangible assets			$ 563,000,000
Eisai
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Amortization of intangible assets	$ 81,000,000	$ 72,000,000
Eisai | Alliance revenue - Lenvima | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Probable contingent payments	125,000,000	$ 125,000,000
Liabilities	$ 250,000,000
Eligible future contingent sales-based milestone payments (up to)			2,300,000,000
Eligible future contingent regulatory milestone payments (up to)			0
Bayer AG | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Eligible future contingent sales-based milestone payments (up to)			$ 0

Collaborative Arrangements - _3

Collaborative Arrangements - Eisai Co., Ltd. (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Cost of sales	$ 3,745		$ 4,024		$ 7,285	$ 7,951
Selling, general and administrative	2,739		2,702		5,221	5,182
Research and development	3,500		13,321		7,492	17,597
Other current assets	38,205				38,205		$ 32,168
Accrued and other current liabilities	14,712				14,712		15,766
Eisai
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Amortization of intangible assets		$ 81		$ 72
Eisai | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue from collaborative arrangement	249		242		504	474
Cost of sales	60		57		121	183
Selling, general and administrative	41		48		80	99
Research and development	6		$ 17		13	$ 56
Other current assets	245				245		226
Accrued and other current liabilities	$ 0				$ 0		$ 125

Collaborative Arrangements - Ba

Collaborative Arrangements - Bayer AG (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Sales	$ 16,112,000,000	$ 15,035,000,000	$ 31,887,000,000	$ 29,522,000,000
Cost of sales	3,745,000,000	4,024,000,000	7,285,000,000	7,951,000,000
Selling, general and administrative	2,739,000,000	2,702,000,000	5,221,000,000	5,182,000,000
Research and development	3,500,000,000	13,321,000,000	7,492,000,000	17,597,000,000
Other current assets	38,205,000,000		38,205,000,000		$ 32,168,000,000
Accrued and other current liabilities	14,712,000,000		14,712,000,000		15,766,000,000
Bayer AG | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Eligible future contingent sales-based milestone payments (up to)	0		0
Revenue from collaborative arrangement	106,000,000	68,000,000	203,000,000	167,000,000
Sales	187,000,000	142,000,000	361,000,000	308,000,000
Cost of sales	61,000,000	56,000,000	123,000,000	113,000,000
Selling, general and administrative	26,000,000	34,000,000	59,000,000	67,000,000
Research and development	28,000,000	25,000,000	55,000,000	50,000,000
Other current assets	170,000,000		170,000,000		156,000,000
Accrued and other current liabilities	81,000,000		81,000,000		$ 80,000,000
Adempas | Bayer AG | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Sales	72,000,000	65,000,000	142,000,000	125,000,000
Adempas | Licenses and Other
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Finite-lived intangible assets	445,000,000		445,000,000
Verquvo | Bayer AG | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Sales	9,000,000	$ 9,000,000	16,000,000	$ 16,000,000
Verquvo | Licenses and Other
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Finite-lived intangible assets	$ 47,000,000		$ 47,000,000

Collaborative Arrangements - Ri

Collaborative Arrangements - Ridgeback Biotherapeutics LP (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Sales	$ 16,112	$ 15,035	$ 31,887	$ 29,522
Cost of sales	3,745	4,024	7,285	7,951
Selling, general and administrative	2,739	2,702	5,221	5,182
Other current assets	38,205		38,205		$ 32,168
Accrued and other current liabilities	14,712		14,712		15,766
Ridgeback Biotherapeutics LP | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Cost of sales	96	193	287	414
Selling, general and administrative	16	24	32	51
Research and development	7	10	2	26
Other current assets	8		8		0
Accrued and other current liabilities	24		24		$ 113
Ridgeback Biotherapeutics LP | Lagevrio | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Sales	$ 110	$ 203	$ 460	$ 595

Collaborative Arrangements - Da

Collaborative Arrangements - Daiicho Sankyo - Narrative (Details) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Oct. 31, 2023 USD ($) candidate
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Research and development	$ 3,500		$ 13,321	$ 7,492	$ 17,597
Daiichi Sankyo | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Number of antibody drug conjugates obtained right and obligations | candidate						3
Aggregate upfront payments due upon execution in collaborative arrangement						$ 4,000
Refundable upfront payments in collaborative arrangement						1,000
Maximum aggregate contingent milestone payments, per product, in collaborative arrangement						$ 5,500
Research and development	$ 65	$ 5,500	$ 0	$ 133	$ 0
Sales based royalty percentage						5%
Daiichi Sankyo | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement | Ifinatamab Deruxtecan
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Refundable upfront payments in collaborative arrangement						$ 500
Daiichi Sankyo | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement | Patritumab Deruxtecan
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Refundable upfront payments in collaborative arrangement						500
Aggregate upfront payments due upon lapse of time in collaborative arrangement						750
Daiichi Sankyo | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement | Raludotatug Deruxtecan
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Aggregate upfront payments due upon lapse of time in collaborative arrangement						$ 750
Liable contracted portion of research and development expenses to incur costs for in collaborative arrangement, percentage						75%
Liable contracted portion of research and development expenses to incur costs for in collaborative arrangement						$ 2,000
Daiichi Sankyo | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement | Patritumab Deruxtecan And Raludotatug Deruxtecan
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Aggregate upfront payments due upon lapse of time in collaborative arrangement		$ 1,500

Collaborative Arrangements - _4

Collaborative Arrangements - Daiicho Sankyo (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2024	Dec. 31, 2023	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Selling, general and administrative	$ 2,739		$ 2,702	$ 5,221	$ 5,182
Research and development	3,500		13,321	7,492	17,597
Accrued and other current liabilities	14,712	$ 15,766		14,712
Daiichi Sankyo | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Selling, general and administrative	14		0	16	0
Research and development	65	5,500	$ 0	133	$ 0
Accrued and other current liabilities	801	800		801
Other noncurrent liabilities	$ 750	$ 750		$ 750

Collaborative Arrangements - Mo

Collaborative Arrangements - Moderna, Inc. - Narrative (Details) $ in Millions	Jun. 30, 2024 USD ($)
Moderna, Inc. | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Capitalization of shared costs	$ 135

Collaborative Arrangements - _5

Collaborative Arrangements - Moderna, Inc. (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Selling, general and administrative	$ 2,739	$ 2,702	$ 5,221	$ 5,182
Research and development	3,500	13,321	7,492	17,597
Accrued and other current liabilities	14,712		14,712		$ 15,766
Moderna, Inc. | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Selling, general and administrative	4	1	6	2
Research and development	93	$ 60	162	$ 86
Accrued and other current liabilities	$ 73		$ 73		$ 63

Collaborative Arrangements - Br

Collaborative Arrangements - Bristol Meyers Squibb Company - Narrative (Details) - Bristol Myers Squibb Company - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Licensing Agreements
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Royalty rate, deduction			0.50
Licensing Agreements | Alliance Revenue - Reblozyl
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Eligible future contingent sales-based milestone payments (up to)	$ 80		$ 80
Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue from collaborative arrangement	$ 90	$ 47	$ 161	$ 90
Minimum | Licensing Agreements
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Royalty rate			20%
Maximum | Licensing Agreements
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Royalty rate			24%

Restructuring - Narrative (Deta

Restructuring - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs			$ 422
Restructuring Program, 2024
Restructuring Cost and Reserve [Line Items]
Expected restructuring and related cost	$ 4,000		4,000
Estimate of cumulative pre tax costs that will be noncash	60%
Total pretax restructuring costs	$ 177		422
Cumulative costs since program inception	$ 613		$ 613
Restructuring Program, 2019
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs		$ 236		$ 333

Restructuring - Charges Activit

Restructuring - Charges Activities by Type of Cost (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs			$ 422
Restructuring Program, 2024
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs	$ 177		422
Restructuring Program, 2019
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs		$ 236		$ 333
Accelerated Depreciation
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs			131
Accelerated Depreciation | Restructuring Program, 2024
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs	66		131
Accelerated Depreciation | Restructuring Program, 2019
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs		22		43
Separation Costs
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs			111
Separation Costs | Restructuring Program, 2024
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs	19		111
Separation Costs | Restructuring Program, 2019
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs		110		151
Other Exit Costs
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs			180
Other Exit Costs | Restructuring Program, 2024
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs	92		180
Other Exit Costs | Restructuring Program, 2019
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs		104		139
Cost of sales | Restructuring Program, 2024
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs	66		182
Cost of sales | Restructuring Program, 2019
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs		32		61
Cost of sales | Accelerated Depreciation | Restructuring Program, 2024
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs	66		131
Cost of sales | Accelerated Depreciation | Restructuring Program, 2019
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs		22		43
Cost of sales | Separation Costs | Restructuring Program, 2024
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs	0		0
Cost of sales | Separation Costs | Restructuring Program, 2019
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs		0		0
Cost of sales | Other Exit Costs | Restructuring Program, 2024
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs	0		51
Cost of sales | Other Exit Costs | Restructuring Program, 2019
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs		10		18
Selling, general and administrative | Restructuring Program, 2024
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs	31		36
Selling, general and administrative | Restructuring Program, 2019
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs		52		53
Selling, general and administrative | Accelerated Depreciation | Restructuring Program, 2024
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs	0		0
Selling, general and administrative | Accelerated Depreciation | Restructuring Program, 2019
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs		0		0
Selling, general and administrative | Separation Costs | Restructuring Program, 2024
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs	0		0
Selling, general and administrative | Separation Costs | Restructuring Program, 2019
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs		0		0
Selling, general and administrative | Other Exit Costs | Restructuring Program, 2024
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs	31		36
Selling, general and administrative | Other Exit Costs | Restructuring Program, 2019
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs		52		53
Research and development | Restructuring Program, 2024
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs	0		2
Research and development | Restructuring Program, 2019
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs		1		1
Research and development | Accelerated Depreciation | Restructuring Program, 2024
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs	0		0
Research and development | Accelerated Depreciation | Restructuring Program, 2019
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs		0		0
Research and development | Separation Costs | Restructuring Program, 2024
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs	0		0
Research and development | Separation Costs | Restructuring Program, 2019
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs		0		0
Research and development | Other Exit Costs | Restructuring Program, 2024
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs	0		2
Research and development | Other Exit Costs | Restructuring Program, 2019
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs		1		1
Restructuring costs | Restructuring Program, 2024
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs	80		202
Restructuring costs | Restructuring Program, 2019
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs		151		218
Restructuring costs | Accelerated Depreciation | Restructuring Program, 2024
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs	0		0
Restructuring costs | Accelerated Depreciation | Restructuring Program, 2019
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs		0		0
Restructuring costs | Separation Costs | Restructuring Program, 2024
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs	19		111
Restructuring costs | Separation Costs | Restructuring Program, 2019
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs		110		151
Restructuring costs | Other Exit Costs | Restructuring Program, 2024
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs	$ 61		$ 91
Restructuring costs | Other Exit Costs | Restructuring Program, 2019
Restructuring Cost and Reserve [Line Items]
Total pretax restructuring costs		$ 41		$ 67

Restructuring - Activities by P

Restructuring - Activities by Program (Details) $ in Millions	6 Months Ended
	Jun. 30, 2024 USD ($)
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	$ 712
Expenses	422
(Payments) receipts, net	(205)
Non-cash activity	(242)
Restructuring reserve, ending balance	687
Accelerated Depreciation
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	0
Expenses	131
(Payments) receipts, net	0
Non-cash activity	(131)
Restructuring reserve, ending balance	0
Separation Costs
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	681
Expenses	111
(Payments) receipts, net	(132)
Non-cash activity	0
Restructuring reserve, ending balance	660
Other Exit Costs
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	31
Expenses	180
(Payments) receipts, net	(73)
Non-cash activity	(111)
Restructuring reserve, ending balance	$ 27

Financial Instruments - Narrati

Financial Instruments - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Derivative [Line Items]
Pretax net unrealized gain on derivatives maturing within the next 12 months estimated to be reclassified from AOCI to sales	$ 190		$ 190
Equity investments without readily determinable fair values	936	$ 949	936	$ 949
Unrealized gains recognized on investments in equity securities without readily determinable fair value			61	3
Unrealized losses recognized on investments in equity securities without readily determinable fair values			5	23
Cumulative unrealized gains on investments	355		355
Cumulative unrealized losses on investments	69		69
(Income) loss from investments in equity securities, net	(56)	175	(200)	(274)
Fair value of loans payable and long-term debt, including current portion	33,500		33,500		$ 32,000
Debt, carrying amount	37,800		37,800		35,100
Factored accounts receivable			2,900		3,000
Cash collateral received from counterparties	123		123		3
Equity Funds
Derivative [Line Items]
Equity securities held through ownership interest in investments funds	278	622	278	622
(Income) loss from investments in equity securities, net	(7)	$ 105	(5)	$ (27)
Accounts Receivable Factoring Collections
Derivative [Line Items]
Restricted cash	42		42		44
Level 2
Derivative [Line Items]
Cash equivalents	$ 10,500		$ 10,500		$ 6,000
Maximum | Derivatives Designated as Hedging Instruments
Derivative [Line Items]
Maximum average period of maturities of contracts in years (less than)			2 years
Maximum | Derivatives Not Designated as Hedging Instruments
Derivative [Line Items]
Maximum average period of maturities of contracts in years (less than)			6 months

Financial Instruments - Effect

Financial Instruments - Effect of Net Investment Hedges (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Pretax (Gain) Loss Recognized in Other Comprehensive Income	$ 5	$ 0	$ 3	$ 1
Foreign exchange contracts | Other (income) expense, net
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Pretax Loss Recognized in Other (income) expense, net for Amounts Excluded from Effectiveness Testing	1	0	1	(1)
Euro-denominated notes
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Pretax (Gain) Loss Recognized in Other Comprehensive Income	(34)	21	(96)	73
Euro-denominated notes | Other (income) expense, net
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Pretax Loss Recognized in Other (income) expense, net for Amounts Excluded from Effectiveness Testing	$ 0	$ 0	$ 0	$ 0

Financial Instruments - Summary

Financial Instruments - Summary of Interest Rate Swaps Held (Details)	Jun. 30, 2024 USD ($) interest_rate_swap	May 31, 2024 EUR (€)	Dec. 31, 2023 USD ($)
Derivative [Line Items]
U.S dollar notional amount	$ 33,098,000,000		$ 30,551,000,000
Senior Notes
Derivative [Line Items]
Par Value of Debt | €		€ 3,400,000,000
4.50% note due 2033 | Senior Notes
Derivative [Line Items]
Stated interest rate	4.50%
Interest rate swap contracts
Derivative [Line Items]
Number of Interest Rate Swaps Held | interest_rate_swap	6
Interest rate swap contracts | 4.50% note due 2033
Derivative [Line Items]
Par Value of Debt	$ 1,500,000,000
Number of Interest Rate Swaps Held | interest_rate_swap	6
U.S dollar notional amount	$ 1,500,000,000

Financial Instruments - Amounts

Financial Instruments - Amounts Recorded on Balance Sheet Related to Fair Value Hedges (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Hedged Liability, Statement of Financial Position [Extensible Enumeration]	Long-Term Debt	Long-Term Debt
Carrying Amount of Hedged Liabilities	$ 1,521	$ 1,056
Cumulative Amount of Fair Value Hedging Adjustment Increase Included in the Carrying Amount	$ 30	$ 56

Financial Instruments - Fair Va

Financial Instruments - Fair Value of Derivatives Segregated between those Derivatives that are Designated as Hedging Instruments and those that are Not Designated as Hedging Instruments (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Derivatives, Fair Value [Line Items]
Fair value of derivative, asset	$ 491	$ 342
Fair value of derivative, liability	142	239
U.S dollar notional amount	33,098	30,551
Derivatives Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Fair value of derivative, asset	302	189
Fair value of derivative, liability	5	77
U.S dollar notional amount	13,513	12,754
Derivatives Not Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Fair value of derivative, asset	189	153
Fair value of derivative, liability	137	162
U.S dollar notional amount	19,585	17,797
Interest rate swap contracts | Derivatives Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Fair value of derivative, asset	$ 30	$ 57
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other Assets	Other Assets
U.S dollar notional amount	$ 1,500	$ 1,000
Foreign exchange contracts | Derivatives Designated as Hedging Instruments | Other Assets
Derivatives, Fair Value [Line Items]
Fair value of derivative, asset	$ 46	$ 26
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other Assets	Other Assets
U.S dollar notional amount	$ 2,052	$ 1,929
Foreign exchange contracts | Derivatives Designated as Hedging Instruments | Other current assets
Derivatives, Fair Value [Line Items]
Fair value of derivative, asset	$ 226	$ 106
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other current assets	Other current assets
U.S dollar notional amount	$ 8,830	$ 6,138
Foreign exchange contracts | Derivatives Designated as Hedging Instruments | Accrued and other current liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative, liability	$ 4	$ 76
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Accrued and other current liabilities	Accrued and other current liabilities
U.S dollar notional amount	$ 901	$ 3,680
Foreign exchange contracts | Derivatives Designated as Hedging Instruments | Other Noncurrent Liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative, liability	$ 1	$ 1
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Other Noncurrent Liabilities	Other Noncurrent Liabilities
U.S dollar notional amount	$ 230	$ 7
Foreign exchange contracts | Derivatives Not Designated as Hedging Instruments | Other Assets
Derivatives, Fair Value [Line Items]
Fair value of derivative, asset	$ 2	$ 0
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other Assets	Other Assets
U.S dollar notional amount	$ 22	$ 0
Foreign exchange contracts | Derivatives Not Designated as Hedging Instruments | Other current assets
Derivatives, Fair Value [Line Items]
Fair value of derivative, asset	$ 187	$ 153
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other current assets	Other current assets
U.S dollar notional amount	$ 8,723	$ 9,693
Foreign exchange contracts | Derivatives Not Designated as Hedging Instruments | Accrued and other current liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative, liability	$ 135	$ 162
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Accrued and other current liabilities	Accrued and other current liabilities
U.S dollar notional amount	$ 10,818	$ 8,104
Foreign exchange contracts | Derivatives Not Designated as Hedging Instruments | Other Noncurrent Liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative, liability	$ 2	$ 0
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Other Noncurrent Liabilities	Other Noncurrent Liabilities
U.S dollar notional amount	$ 22	$ 0

Financial Instruments - Informa

Financial Instruments - Information on Derivative Positions Subject to Master Netting Arrangements as if they were Presented on a Net Basis (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Gross amounts recognized in the consolidated balance sheet, asset	$ 491	$ 342
Gross amount subject to offset in master netting arrangements not offset in the condensed balance sheet, asset	(114)	(215)
Cash collateral received, asset	(123)	(3)
Net amounts, asset	254	124
Gross amounts recognized in the consolidated balance sheet, liability	142	239
Gross amount subject to offset in master netting arrangements not offset in the condensed balance sheet, liability	(114)	(215)
Cash collateral received, liability	0	0
Net amounts, liability	$ 28	$ 24

Financial Instruments - Locatio

Financial Instruments - Location and Amount of Pretax (Gains) Losses of Derivatives (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Derivative Instruments, Gain (Loss) [Line Items]
Sales	$ 16,112	$ 15,035	$ 31,887	$ 29,522
Other (income) expense, net	42	172	12	259
Other comprehensive income (loss)	(87)	(17)	$ (200)	$ (132)
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]			Other (income) expense, net	Other (income) expense, net
Interest rate swap contracts | Other (income) expense, net
Derivative Instruments, Gain (Loss) [Line Items]
Hedged items	4		$ (26)
Derivatives designated as hedging instruments	(4)		27
Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in OCI on derivatives	139	194	348	$ 128
Increase in Sales as a result of AOCL reclassifications	(54)	(24)	(98)	(125)
Foreign exchange contracts | Reclassification out of Accumulated Other Comprehensive Income | Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest
Derivative Instruments, Gain (Loss) [Line Items]
Sales	$ 54	24	98	125
Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in OCI on derivatives		$ 13	(1)	13
Amount of gain recognized in Other (income) expense, net on derivatives			$ (1)	$ (1)

Financial Instruments - Income

Financial Instruments - Income Statement Effects on Derivatives Not Designated as Hedging Instruments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Currency Swap | Other (income) expense, net
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Derivative Pretax (Gain) Loss Recognized in Income	$ 9	$ (41)	$ 75	$ (28)
Foreign Exchange Future | Sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Derivative Pretax (Gain) Loss Recognized in Income	$ (10)	$ (5)	$ (20)	$ (3)

Financial Instruments - Infor_2

Financial Instruments - Information on Available-for-sale Investments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Debt securities, amortized cost	$ 127		$ 127		$ 337
Debt securities, unrealized gains	0		0		0
Debt securities, unrealized losses	0		0		0
Debt securities, fair value	127		127		337
Publicly traded equity securities, fair value	1,026		1,026		764
Total debt and publicly traded equity securities, fair value	1,153		1,153		1,101
Unrealized net losses (gains)	8	$ 71	(125)	$ (267)
U.S. government and agency securities
Debt Securities, Available-for-sale [Line Items]
Debt securities, amortized cost	77		77		72
Debt securities, unrealized gains	0		0		0
Debt securities, unrealized losses	0		0		0
Debt securities, fair value	77		77		72
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Debt securities, amortized cost	50		50		252
Debt securities, unrealized gains	0		0		0
Debt securities, unrealized losses	0		0		0
Debt securities, fair value	50		50		252
Corporate notes and bonds
Debt Securities, Available-for-sale [Line Items]
Debt securities, amortized cost	0		0		13
Debt securities, unrealized gains	0		0		0
Debt securities, unrealized losses	0		0		0
Debt securities, fair value	$ 0		$ 0		$ 13

Financial Instruments - Financi

Financial Instruments - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023	Jun. 30, 2023	Dec. 31, 2022
Assets
Investments	$ 127	$ 337
Publicly traded equity securities	1,026	764
Other Assets	12,702	11,996
Fair value of derivative, asset	491	342
Liabilities
Contingent consideration	225	354	$ 349	$ 456
Fair value of derivative, liability	142	239
Commercial paper
Assets
Investments	50	252
U.S. government and agency securities
Assets
Investments	77	72
Corporate notes and bonds
Assets
Investments	0	13
Fair Value, Measurements, Recurring
Assets
Investments	407	504
Other Assets	746	597
Fair value of derivative, asset	491	342
Total assets	1,644	1,443
Liabilities
Contingent consideration	225	354
Fair value of derivative, liability	142	239
Total liabilities	367	593
Fair Value, Measurements, Recurring | Foreign exchange contracts
Assets
Fair value of derivative, asset	278	202
Liabilities
Fair value of derivative, liability	115	239
Fair Value, Measurements, Recurring | Currency options
Assets
Fair value of derivative, asset	183	83
Liabilities
Fair value of derivative, liability	27	0
Fair Value, Measurements, Recurring | Interest rate swap contracts
Assets
Fair value of derivative, asset	30	57
Fair Value, Measurements, Recurring | Level 1
Assets
Investments	357	252
Other Assets	746	597
Fair value of derivative, asset	0	0
Total assets	1,103	849
Liabilities
Contingent consideration	0	0
Fair value of derivative, liability	0	0
Total liabilities	0	0
Fair Value, Measurements, Recurring | Level 1 | Foreign exchange contracts
Assets
Fair value of derivative, asset	0	0
Liabilities
Fair value of derivative, liability	0	0
Fair Value, Measurements, Recurring | Level 1 | Currency options
Assets
Fair value of derivative, asset	0	0
Liabilities
Fair value of derivative, liability	0	0
Fair Value, Measurements, Recurring | Level 1 | Interest rate swap contracts
Assets
Fair value of derivative, asset	0	0
Fair Value, Measurements, Recurring | Level 2
Assets
Investments	50	252
Other Assets	0	0
Fair value of derivative, asset	491	342
Total assets	541	594
Liabilities
Contingent consideration	0	0
Fair value of derivative, liability	142	239
Total liabilities	142	239
Fair Value, Measurements, Recurring | Level 2 | Foreign exchange contracts
Assets
Fair value of derivative, asset	278	202
Liabilities
Fair value of derivative, liability	115	239
Fair Value, Measurements, Recurring | Level 2 | Currency options
Assets
Fair value of derivative, asset	183	83
Liabilities
Fair value of derivative, liability	27	0
Fair Value, Measurements, Recurring | Level 2 | Interest rate swap contracts
Assets
Fair value of derivative, asset	30	57
Fair Value, Measurements, Recurring | Level 3
Assets
Investments	0	0
Other Assets	0	0
Fair value of derivative, asset	0	0
Total assets	0	0
Liabilities
Contingent consideration	225	354
Fair value of derivative, liability	0	0
Total liabilities	225	354
Fair Value, Measurements, Recurring | Level 3 | Foreign exchange contracts
Assets
Fair value of derivative, asset	0	0
Liabilities
Fair value of derivative, liability	0	0
Fair Value, Measurements, Recurring | Level 3 | Currency options
Assets
Fair value of derivative, asset	0	0
Liabilities
Fair value of derivative, liability	0	0
Fair Value, Measurements, Recurring | Level 3 | Interest rate swap contracts
Assets
Fair value of derivative, asset	0	0
Fair Value, Measurements, Recurring | Commercial paper
Assets
Investments	50	252
Fair Value, Measurements, Recurring | Commercial paper | Level 1
Assets
Investments	0	0
Fair Value, Measurements, Recurring | Commercial paper | Level 2
Assets
Investments	50	252
Fair Value, Measurements, Recurring | Commercial paper | Level 3
Assets
Investments	0	0
Fair Value, Measurements, Recurring | U.S. government and agency securities
Assets
Debt securities, available-for-sale, noncurrent	77	72
Fair Value, Measurements, Recurring | U.S. government and agency securities | Level 1
Assets
Debt securities, available-for-sale, noncurrent	77	72
Fair Value, Measurements, Recurring | U.S. government and agency securities | Level 2
Assets
Debt securities, available-for-sale, noncurrent	0	0
Fair Value, Measurements, Recurring | U.S. government and agency securities | Level 3
Assets
Debt securities, available-for-sale, noncurrent	0	0
Fair Value, Measurements, Recurring | Corporate notes and bonds
Assets
Debt securities, available-for-sale, noncurrent	0	13
Fair Value, Measurements, Recurring | Corporate notes and bonds | Level 1
Assets
Debt securities, available-for-sale, noncurrent	0	13
Fair Value, Measurements, Recurring | Corporate notes and bonds | Level 2
Assets
Debt securities, available-for-sale, noncurrent	0	0
Fair Value, Measurements, Recurring | Corporate notes and bonds | Level 3
Assets
Debt securities, available-for-sale, noncurrent	0	0
Fair Value, Measurements, Recurring | Publicly traded equity securities
Assets
Publicly traded equity securities	357	252
Publicly traded equity securities	669	512
Fair Value, Measurements, Recurring | Publicly traded equity securities | Level 1
Assets
Publicly traded equity securities	357	252
Publicly traded equity securities	669	512
Liabilities
Securities, fair value, which are subject to a contractual sale restriction	285
Fair Value, Measurements, Recurring | Publicly traded equity securities | Level 2
Assets
Publicly traded equity securities	0	0
Publicly traded equity securities	0	0
Fair Value, Measurements, Recurring | Publicly traded equity securities | Level 3
Assets
Publicly traded equity securities	0	0
Publicly traded equity securities	$ 0	$ 0

Financial Instruments - Infor_3

Financial Instruments - Information About Changes in Liabilities for Contingent Consideration (Details) $ in Millions	6 Months Ended
	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning balance	$ 354	$ 456
Changes in estimated fair value	(3)	10
Payments	(126)	(117)
Fair value, ending balance	225	$ 349
Sanofi Pasteur
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Current liability	$ 131
Contingent consideration, measurement input, discount rate	0.115

Inventories - Schedule of Inven

Inventories - Schedule of Inventories (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Inventory Disclosure [Abstract]
Finished goods	$ 1,889	$ 1,954
Raw materials and work in process	8,456	8,037
Supplies	267	277
Total	10,612	10,268
Decrease to LIFO cost	(687)	(562)
Total current and noncurrent inventories	9,925	9,706
Recognized as:
Inventories	6,469	6,358
Other Assets	$ 3,456	$ 3,348

Inventories - Narrative (Detail

Inventories - Narrative (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Inventory [Line Items]
Inventories classified in Other assets	$ 3,456	$ 3,348
Inventories Not Expected to be Sold Within One Year
Inventory [Line Items]
Inventories classified in Other assets	3,200	2,600
Inventories Produced in Preparation for Product Launches
Inventory [Line Items]
Inventories classified in Other assets	$ 250	$ 790

Long-Term Debt (Details)

Long-Term Debt (Details) - Senior Notes	May 31, 2024 EUR (€)
Debt Instrument [Line Items]
Face amount of debt	€ 3,400,000,000
3.25% Notes due 2032
Debt Instrument [Line Items]
Face amount of debt	€ 850,000,000
Stated interest rate	3.25%
3.50% Notes due 2037
Debt Instrument [Line Items]
Face amount of debt	€ 850,000,000
Stated interest rate	3.50%
3.70% Notes due 2044
Debt Instrument [Line Items]
Face amount of debt	€ 850,000,000
Stated interest rate	3.70%
3.75% Notes due 2054
Debt Instrument [Line Items]
Face amount of debt	€ 850,000,000
Stated interest rate	3.75%

Contingencies (Details)

Contingencies (Details) $ in Millions			1 Months Ended			6 Months Ended
	Mar. 15, 2024	Apr. 13, 2023 patent	Feb. 29, 2024 patent	Jun. 30, 2023	Feb. 28, 2023 patent	Jun. 30, 2024 USD ($) company case	Dec. 31, 2023 USD ($)
Legal Defense Costs
Loss Contingencies [Line Items]
Legal defense costs reserve | $						$ 215	$ 210
Gardasil/Gardasil 9 | Non-US | Pending Litigation
Loss Contingencies [Line Items]
Loss contingency, pending claims | case						15
Bridion | Patents
Loss Contingencies [Line Items]
Loss contingency, claims settled						5
Bridion | Pending Litigation | Patents
Loss Contingencies [Line Items]
Loss contingency, pending claims						2
Postponement period resulting from litigation	30 months
Bridion | Settled Litigation | Patents
Loss Contingencies [Line Items]
Patent extension, term				5 years
Keytruda | Pending Litigation | Patents
Loss Contingencies [Line Items]
Loss contingency, number of patents allegedly infringed | patent		9
Lynparza | Pending Litigation | Patents
Loss Contingencies [Line Items]
Loss contingency, number of patents allegedly infringed | patent			1		1
Januvia/Janumet
Loss Contingencies [Line Items]
Loss contingency, claims settled						26

Equity (Details)

Equity (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, beginning balance (in shares)			3,577,103,522
Treasury stock, beginning balance (in shares)			1,045,470,249
Equity, beginning balance	$ 40,424	$ 46,905	$ 37,635	$ 46,058
Net (loss) income attributable to Merck & Co., Inc.	5,455	(5,975)	10,217	(3,154)
Other comprehensive income (loss), net of taxes	(87)	(17)	(200)	(132)
Cash dividends declared on common stock	(1,965)	(1,866)	(3,925)	(3,729)
Treasury stock shares purchased	(251)	(338)	(373)	(487)
Share-based compensation plans and other	66	55	283	204
Net income attributable to noncontrolling interests	$ 6	3	$ 11	7
Distributions attributable to noncontrolling interests		(25)		(25)
Common stock, ending balance (in shares)	3,577,103,522		3,577,103,522
Treasury stock, ending balance (in shares)	1,041,454,052		1,041,454,052
Equity, ending balance	$ 43,648	$ 38,742	$ 43,648	$ 38,742
Cash dividends declared on common stock (in dollars per share)	$ 0.77	$ 0.73	$ 1.54	$ 1.46
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, beginning balance (in shares)	3,577,000,000	3,577,000,000	3,577,000,000	3,577,000,000
Equity, beginning balance	$ 1,788	$ 1,788	$ 1,788	$ 1,788
Common stock, ending balance (in shares)	3,577,000,000	3,577,000,000	3,577,000,000	3,577,000,000
Equity, ending balance	$ 1,788	$ 1,788	$ 1,788	$ 1,788
Other Paid-In Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity, beginning balance	44,598	44,467	44,509	44,379
Share-based compensation plans and other	(236)	(248)	(147)	(160)
Equity, ending balance	44,362	44,219	44,362	44,219
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity, beginning balance	56,697	62,039	53,895	61,081
Net (loss) income attributable to Merck & Co., Inc.	5,455	(5,975)	10,217	(3,154)
Cash dividends declared on common stock	(1,965)	(1,866)	(3,925)	(3,729)
Equity, ending balance	60,187	54,198	60,187	54,198
Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity, beginning balance	(5,274)	(4,883)	(5,161)	(4,768)
Other comprehensive income (loss), net of taxes	(87)	(17)	(200)	(132)
Equity, ending balance	$ (5,361)	$ (4,900)	$ (5,361)	$ (4,900)
Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury stock, beginning balance (in shares)	1,044,000,000	1,040,000,000	1,045,000,000	1,039,000,000
Equity, beginning balance	$ (57,445)	$ (56,577)	$ (57,450)	$ (56,489)
Treasury stock shares purchased (in shares)	2,000,000	3,000,000	3,000,000	4,000,000
Treasury stock shares purchased	$ (251)	$ (338)	$ (373)	$ (487)
Share-based compensation plans and other (in shares)	(5,000,000)	(5,000,000)	(7,000,000)	(5,000,000)
Share-based compensation plans and other	$ 302	$ 303	$ 429	$ 364
Treasury stock, ending balance (in shares)	1,041,000,000	1,038,000,000	1,041,000,000	1,038,000,000
Equity, ending balance	$ (57,394)	$ (56,612)	$ (57,394)	$ (56,612)
Non- controlling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity, beginning balance	60	71	54	67
Net income attributable to noncontrolling interests	6	3	11	7
Distributions attributable to noncontrolling interests		(25)		(25)
Equity, ending balance	$ 66	$ 49	$ 66	$ 49

Pension and Other Postretirem_3

Pension and Other Postretirement Benefit Plans - Net Benefit Costs (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Other Postretirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 8	$ 8	$ 15	$ 17
Interest cost	14	16	28	31
Expected return on plan assets	(20)	(16)	(40)	(32)
Amortization of unrecognized prior service (credit) cost	(11)	(12)	(21)	(25)
Net loss (gain) amortization	(12)	(11)	(24)	(21)
Net periodic benefit cost	(21)	(15)	(42)	(30)
U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	86	76	173	152
Interest cost	134	133	269	266
Expected return on plan assets	(207)	(185)	(417)	(372)
Amortization of unrecognized prior service (credit) cost	0	0	0	(1)
Net loss (gain) amortization	10	0	20	0
Termination benefits	0	1	4	1
Curtailments	0	2	0	5
Settlements	0	5	0	26
Net periodic benefit cost	23	32	49	77
International | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	60	50	122	99
Interest cost	73	75	147	149
Expected return on plan assets	(137)	(130)	(278)	(257)
Amortization of unrecognized prior service (credit) cost	(3)	16	(6)	12
Net loss (gain) amortization	1	(1)	3	(2)
Termination benefits	0	0	0	0
Curtailments	0	0	0	0
Settlements	0	0	0	0
Net periodic benefit cost	$ (6)	$ 10	$ (12)	$ 1

Pension and Other Postretirem_4

Pension and Other Postretirement Benefit Plans - Narrative (Details) $ in Millions	3 Months Ended
	Mar. 31, 2023 USD ($)
Retirement Benefits [Abstract]
Increase to pension liabilities due to remeasurement	$ 47

Other (Income) Expense, Net - S

Other (Income) Expense, Net - Schedule of Other (Income) Expense, Net (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Other Income and Expenses [Abstract]
Interest income	$ (69)	$ (109)	$ (141)	$ (221)
Interest expense	310	277	613	519
Exchange losses	60	62	144	122
(Income) loss from investments in equity securities, net	(56)	175	(200)	(274)
Net periodic defined benefit plan (credit) cost other than service cost	(159)	(111)	(319)	(226)
Other, net	(44)	(122)	(85)	339
Other (income) expense, net	$ 42	$ 172	$ 12	$ 259

Other (Income) Expense, Net - N

Other (Income) Expense, Net - Narrative (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Loss Contingencies [Line Items]
Interest paid	$ 581	$ 449
Zetia antitrust litigation
Loss Contingencies [Line Items]
Loss related to litigation settlement		$ 572.5

Income Taxes (Details)

Income Taxes (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Income Tax Disclosure [Abstract]
Effective income tax rate	9.10%	(11.90%)	12.40%	(86.80%)
Income tax rate, favorable impact	4.30%		2.20%
Tax benefit resulting from a reduction in reserves for unrecognized tax benefits	$ 259,000,000		$ 259,000,000
Income tax rate, unfavorable discrete impact		25.10%	0.70%	101.90%
Tax benefit resulting from acquisition charge		$ 0	$ 0	$ 0
Income tax provision	545,000,000	637,000,000	1,447,000,000	1,462,000,000
Pretax losses	$ 6,006,000,000	$ (5,335,000,000)	$ 11,675,000,000	$ (1,685,000,000)

Earnings Per Share - Calculatio

Earnings Per Share - Calculations of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Earnings Per Share [Abstract]
Net Income (Loss) Attributable to Merck & Co., Inc., basic	$ 5,455	$ (5,975)	$ 10,217	$ (3,154)
Net Income (Loss) Attributable to Merck & Co., Inc., diluted	$ 5,455	$ (5,975)	$ 10,217	$ (3,154)
Average common shares outstanding (in shares)	2,534	2,539	2,534	2,539
Common shares issuable (in shares)	10	0	10	0
Average common shares outstanding assuming dilution (in shares)	2,544	2,539	2,544	2,539
Basic Earnings (Loss) per Common Share Attributable to Merck & Co., Inc. Common Shareholders (in dollars per share)	$ 2.15	$ (2.35)	$ 4.03	$ (1.24)
Earnings (Loss) per Common Share Assuming Dilution Attributable to Merck & Co., Inc. Common Shareholders (in dollars per share)	$ 2.14	$ (2.35)	$ 4.02	$ (1.24)

Earnings Per Share - Narrative

Earnings Per Share - Narrative (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Earnings Per Share [Abstract]
Antidilutive shares (in shares)	7,000,000	0	5,000,000	0

Other Comprehensive Income (L_3

Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Equity, beginning balance	$ 40,424	$ 46,905	$ 37,635	$ 46,058
Other comprehensive income (loss), net of taxes	(87)	(17)	(200)	(132)
Equity, ending balance	43,648	38,742	43,648	38,742
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Equity, beginning balance	(5,274)	(4,883)	(5,161)	(4,768)
Other comprehensive income (loss) before reclassification adjustments, pretax	(17)	73	(28)	39
Tax	(34)	(62)	(95)	(66)
Other comprehensive income (loss) before reclassification adjustments, net of taxes	(51)	11	(123)	(27)
Reclassification adjustments, pretax	(50)	(34)	(109)	(134)
Tax	14	6	32	29
Reclassification adjustments, net of taxes	(36)	(28)	(77)	(105)
Other comprehensive income (loss), net of taxes	(87)	(17)	(200)	(132)
Equity, ending balance	(5,361)	(4,900)	(5,361)	(4,900)
Derivatives
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Equity, beginning balance	106	(60)	(24)	73
Other comprehensive income (loss) before reclassification adjustments, pretax	139	194	348	128
Tax	(29)	(41)	(73)	(27)
Other comprehensive income (loss) before reclassification adjustments, net of taxes	110	153	275	101
Reclassification adjustments, pretax	(55)	(11)	(99)	(113)
Tax	12	3	21	24
Reclassification adjustments, net of taxes	(43)	(8)	(78)	(89)
Other comprehensive income (loss), net of taxes	67	145	197	12
Equity, ending balance	173	85	173	85
Employee Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Equity, beginning balance	(2,798)	(2,458)	(2,793)	(2,408)
Other comprehensive income (loss) before reclassification adjustments, pretax	1	(6)	6	(53)
Tax	2	1	(2)	3
Other comprehensive income (loss) before reclassification adjustments, net of taxes	3	(5)	4	(50)
Reclassification adjustments, pretax	(15)	(23)	(30)	(30)
Tax	2	3	11	5
Reclassification adjustments, net of taxes	(13)	(20)	(19)	(25)
Other comprehensive income (loss), net of taxes	(10)	(25)	(15)	(75)
Equity, ending balance	(2,808)	(2,483)	(2,808)	(2,483)
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Equity, beginning balance	(2,582)	(2,365)	(2,344)	(2,433)
Other comprehensive income (loss) before reclassification adjustments, pretax	(157)	(115)	(382)	(36)
Tax	(7)	(22)	(20)	(42)
Other comprehensive income (loss) before reclassification adjustments, net of taxes	(164)	(137)	(402)	(78)
Reclassification adjustments, pretax	20	0	20	9
Tax	0	0	0	0
Reclassification adjustments, net of taxes	20	0	20	9
Other comprehensive income (loss), net of taxes	(144)	(137)	(382)	(69)
Equity, ending balance	$ (2,726)	$ (2,502)	$ (2,726)	$ (2,502)

Segment Reporting - Narrative (

Segment Reporting - Narrative (Details) $ in Billions	3 Months Ended		6 Months Ended
	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) segment	Jun. 30, 2023 USD ($)
Segment Reporting [Abstract]
Number of operating segments | segment			2
Sales discounts | $	$ 3.3	$ 3.2	$ 6.6	$ 6.3

Segment Reporting - Sales from

Segment Reporting - Sales from Products (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Segment Reporting Information [Line Items]
Sales	$ 16,112	$ 15,035	$ 31,887	$ 29,522
Increase in hedge revenue			118	128
Revenue related to the sale of the marketing rights			76	54
U.S.
Segment Reporting Information [Line Items]
Sales	7,876	7,018	15,354	13,676
Non-US
Segment Reporting Information [Line Items]
Sales	8,236	8,018	16,533	15,846
Operating Segments
Segment Reporting Information [Line Items]
Sales	15,890	14,913	31,408	29,126
Operating Segments | U.S.
Segment Reporting Information [Line Items]
Sales	7,854	7,045	15,265	13,644
Operating Segments | Non-US
Segment Reporting Information [Line Items]
Sales	8,036	7,869	16,143	15,482
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Sales	222	122	479	396
Corporate, Non-Segment | U.S.
Segment Reporting Information [Line Items]
Sales	22	(27)	89	32
Corporate, Non-Segment | Non-US
Segment Reporting Information [Line Items]
Sales	200	149	390	364
Pharmaceutical | Operating Segments
Segment Reporting Information [Line Items]
Sales	14,408	13,457	28,415	26,179
Pharmaceutical | Operating Segments | U.S.
Segment Reporting Information [Line Items]
Sales	7,399	6,570	14,336	12,688
Pharmaceutical | Operating Segments | Non-US
Segment Reporting Information [Line Items]
Sales	7,009	6,887	14,079	13,491
Pharmaceutical | Operating Segments | Keytruda
Segment Reporting Information [Line Items]
Sales	7,270	6,271	14,217	12,065
Pharmaceutical | Operating Segments | Keytruda | U.S.
Segment Reporting Information [Line Items]
Sales	4,412	3,863	8,531	7,348
Pharmaceutical | Operating Segments | Keytruda | Non-US
Segment Reporting Information [Line Items]
Sales	2,858	2,408	5,686	4,718
Pharmaceutical | Operating Segments | Alliance revenue - Lynparza
Segment Reporting Information [Line Items]
Sales	317	310	609	585
Pharmaceutical | Operating Segments | Alliance revenue - Lynparza | U.S.
Segment Reporting Information [Line Items]
Sales	153	144	288	286
Pharmaceutical | Operating Segments | Alliance revenue - Lynparza | Non-US
Segment Reporting Information [Line Items]
Sales	165	166	321	299
Pharmaceutical | Operating Segments | Alliance revenue - Lenvima
Segment Reporting Information [Line Items]
Sales	249	242	504	474
Pharmaceutical | Operating Segments | Alliance revenue - Lenvima | U.S.
Segment Reporting Information [Line Items]
Sales	177	163	349	316
Pharmaceutical | Operating Segments | Alliance revenue - Lenvima | Non-US
Segment Reporting Information [Line Items]
Sales	73	79	155	158
Pharmaceutical | Operating Segments | Welireg
Segment Reporting Information [Line Items]
Sales	126	50	211	92
Pharmaceutical | Operating Segments | Welireg | U.S.
Segment Reporting Information [Line Items]
Sales	116	49	194	90
Pharmaceutical | Operating Segments | Welireg | Non-US
Segment Reporting Information [Line Items]
Sales	10	2	17	3
Pharmaceutical | Operating Segments | Alliance Revenue - Reblozyl
Segment Reporting Information [Line Items]
Sales	90	47	161	90
Pharmaceutical | Operating Segments | Alliance Revenue - Reblozyl | U.S.
Segment Reporting Information [Line Items]
Sales	75	36	133	66
Pharmaceutical | Operating Segments | Alliance Revenue - Reblozyl | Non-US
Segment Reporting Information [Line Items]
Sales	15	11	28	24
Pharmaceutical | Operating Segments | Gardasil/Gardasil 9
Segment Reporting Information [Line Items]
Sales	2,478	2,458	4,727	4,430
Pharmaceutical | Operating Segments | Gardasil/Gardasil 9 | U.S.
Segment Reporting Information [Line Items]
Sales	536	464	1,024	880
Pharmaceutical | Operating Segments | Gardasil/Gardasil 9 | Non-US
Segment Reporting Information [Line Items]
Sales	1,941	1,994	3,702	3,550
Pharmaceutical | Operating Segments | ProQuad/M-M-R II/Varivax
Segment Reporting Information [Line Items]
Sales	617	582	1,187	1,109
Pharmaceutical | Operating Segments | ProQuad/M-M-R II/Varivax | U.S.
Segment Reporting Information [Line Items]
Sales	490	447	928	868
Pharmaceutical | Operating Segments | ProQuad/M-M-R II/Varivax | Non-US
Segment Reporting Information [Line Items]
Sales	127	135	259	242
Pharmaceutical | Operating Segments | Vaxneuvance
Segment Reporting Information [Line Items]
Sales	189	168	408	274
Pharmaceutical | Operating Segments | Vaxneuvance | U.S.
Segment Reporting Information [Line Items]
Sales	99	147	260	241
Pharmaceutical | Operating Segments | Vaxneuvance | Non-US
Segment Reporting Information [Line Items]
Sales	90	20	148	33
Pharmaceutical | Operating Segments | RotaTeq
Segment Reporting Information [Line Items]
Sales	163	131	379	428
Pharmaceutical | Operating Segments | RotaTeq | U.S.
Segment Reporting Information [Line Items]
Sales	107	93	257	273
Pharmaceutical | Operating Segments | RotaTeq | Non-US
Segment Reporting Information [Line Items]
Sales	56	37	123	155
Pharmaceutical | Operating Segments | Pneumovax 23
Segment Reporting Information [Line Items]
Sales	59	92	120	188
Pharmaceutical | Operating Segments | Pneumovax 23 | U.S.
Segment Reporting Information [Line Items]
Sales	11	23	17	63
Pharmaceutical | Operating Segments | Pneumovax 23 | Non-US
Segment Reporting Information [Line Items]
Sales	48	69	103	125
Pharmaceutical | Operating Segments | Bridion
Segment Reporting Information [Line Items]
Sales	455	502	895	989
Pharmaceutical | Operating Segments | Bridion | U.S.
Segment Reporting Information [Line Items]
Sales	351	299	680	576
Pharmaceutical | Operating Segments | Bridion | Non-US
Segment Reporting Information [Line Items]
Sales	104	203	215	413
Pharmaceutical | Operating Segments | Prevymis
Segment Reporting Information [Line Items]
Sales	188	143	362	273
Pharmaceutical | Operating Segments | Prevymis | U.S.
Segment Reporting Information [Line Items]
Sales	90	61	165	116
Pharmaceutical | Operating Segments | Prevymis | Non-US
Segment Reporting Information [Line Items]
Sales	98	82	197	157
Pharmaceutical | Operating Segments | Dificid
Segment Reporting Information [Line Items]
Sales	92	76	165	141
Pharmaceutical | Operating Segments | Dificid | U.S.
Segment Reporting Information [Line Items]
Sales	79	68	147	130
Pharmaceutical | Operating Segments | Dificid | Non-US
Segment Reporting Information [Line Items]
Sales	12	8	17	11
Pharmaceutical | Operating Segments | Zerbaxa
Segment Reporting Information [Line Items]
Sales	62	54	118	104
Pharmaceutical | Operating Segments | Zerbaxa | U.S.
Segment Reporting Information [Line Items]
Sales	33	30	67	57
Pharmaceutical | Operating Segments | Zerbaxa | Non-US
Segment Reporting Information [Line Items]
Sales	28	24	51	47
Pharmaceutical | Operating Segments | Noxafil
Segment Reporting Information [Line Items]
Sales	45	55	101	116
Pharmaceutical | Operating Segments | Noxafil | U.S.
Segment Reporting Information [Line Items]
Sales	0	11	8	25
Pharmaceutical | Operating Segments | Noxafil | Non-US
Segment Reporting Information [Line Items]
Sales	44	45	92	91
Pharmaceutical | Operating Segments | Alliance revenue - Adempas/Verquvo
Segment Reporting Information [Line Items]
Sales	106	68	203	167
Pharmaceutical | Operating Segments | Alliance revenue - Adempas/Verquvo | U.S.
Segment Reporting Information [Line Items]
Sales	98	70	188	153
Pharmaceutical | Operating Segments | Alliance revenue - Adempas/Verquvo | Non-US
Segment Reporting Information [Line Items]
Sales	8	(2)	16	14
Pharmaceutical | Operating Segments | Adempas
Segment Reporting Information [Line Items]
Sales	72	65	142	125
Pharmaceutical | Operating Segments | Adempas | U.S.
Segment Reporting Information [Line Items]
Sales	0	0	0	0
Pharmaceutical | Operating Segments | Adempas | Non-US
Segment Reporting Information [Line Items]
Sales	72	65	142	125
Pharmaceutical | Operating Segments | Winrevair
Segment Reporting Information [Line Items]
Sales	70	0	70	0
Pharmaceutical | Operating Segments | Winrevair | U.S.
Segment Reporting Information [Line Items]
Sales	70	0	70	0
Pharmaceutical | Operating Segments | Winrevair | Non-US
Segment Reporting Information [Line Items]
Sales	0	0	0	0
Pharmaceutical | Operating Segments | Lagevrio
Segment Reporting Information [Line Items]
Sales	110	203	460	595
Pharmaceutical | Operating Segments | Lagevrio | U.S.
Segment Reporting Information [Line Items]
Sales	15	2	60	0
Pharmaceutical | Operating Segments | Lagevrio | Non-US
Segment Reporting Information [Line Items]
Sales	95	201	400	595
Pharmaceutical | Operating Segments | Isentress/Isentress HD
Segment Reporting Information [Line Items]
Sales	89	136	200	259
Pharmaceutical | Operating Segments | Isentress/Isentress HD | U.S.
Segment Reporting Information [Line Items]
Sales	43	56	93	108
Pharmaceutical | Operating Segments | Isentress/Isentress HD | Non-US
Segment Reporting Information [Line Items]
Sales	46	80	107	151
Pharmaceutical | Operating Segments | Delstrigo
Segment Reporting Information [Line Items]
Sales	60	50	116	94
Pharmaceutical | Operating Segments | Delstrigo | U.S.
Segment Reporting Information [Line Items]
Sales	14	13	26	24
Pharmaceutical | Operating Segments | Delstrigo | Non-US
Segment Reporting Information [Line Items]
Sales	45	37	89	70
Pharmaceutical | Operating Segments | Pifeltro
Segment Reporting Information [Line Items]
Sales	39	38	81	72
Pharmaceutical | Operating Segments | Pifeltro | U.S.
Segment Reporting Information [Line Items]
Sales	27	27	56	51
Pharmaceutical | Operating Segments | Pifeltro | Non-US
Segment Reporting Information [Line Items]
Sales	12	11	25	21
Pharmaceutical | Operating Segments | Belsomra
Segment Reporting Information [Line Items]
Sales	53	63	99	119
Pharmaceutical | Operating Segments | Belsomra | U.S.
Segment Reporting Information [Line Items]
Sales	19	21	33	37
Pharmaceutical | Operating Segments | Belsomra | Non-US
Segment Reporting Information [Line Items]
Sales	34	42	66	82
Pharmaceutical | Operating Segments | Simponi
Segment Reporting Information [Line Items]
Sales	172	180	356	359
Pharmaceutical | Operating Segments | Simponi | U.S.
Segment Reporting Information [Line Items]
Sales	0	0	0	0
Pharmaceutical | Operating Segments | Simponi | Non-US
Segment Reporting Information [Line Items]
Sales	172	180	356	359
Pharmaceutical | Operating Segments | Remicade
Segment Reporting Information [Line Items]
Sales	35	48	74	99
Pharmaceutical | Operating Segments | Remicade | U.S.
Segment Reporting Information [Line Items]
Sales	0	0	0	0
Pharmaceutical | Operating Segments | Remicade | Non-US
Segment Reporting Information [Line Items]
Sales	35	48	74	99
Pharmaceutical | Operating Segments | Januvia
Segment Reporting Information [Line Items]
Sales	405	511	824	1,062
Pharmaceutical | Operating Segments | Januvia | U.S.
Segment Reporting Information [Line Items]
Sales	177	243	361	514
Pharmaceutical | Operating Segments | Januvia | Non-US
Segment Reporting Information [Line Items]
Sales	227	267	463	548
Pharmaceutical | Operating Segments | Janumet
Segment Reporting Information [Line Items]
Sales	224	354	475	683
Pharmaceutical | Operating Segments | Janumet | U.S.
Segment Reporting Information [Line Items]
Sales	17	82	55	138
Pharmaceutical | Operating Segments | Janumet | Non-US
Segment Reporting Information [Line Items]
Sales	208	272	420	544
Pharmaceutical | Operating Segments | Other pharmaceutical
Segment Reporting Information [Line Items]
Sales	573	560	1,151	1,187
Pharmaceutical | Operating Segments | Other pharmaceutical | U.S.
Segment Reporting Information [Line Items]
Sales	190	158	346	328
Pharmaceutical | Operating Segments | Other pharmaceutical | Non-US
Segment Reporting Information [Line Items]
Sales	386	403	807	857
Animal Health | Operating Segments
Segment Reporting Information [Line Items]
Sales	1,482	1,456	2,993	2,947
Animal Health | Operating Segments | U.S.
Segment Reporting Information [Line Items]
Sales	455	475	929	956
Animal Health | Operating Segments | Non-US
Segment Reporting Information [Line Items]
Sales	1,027	982	2,064	1,991
Animal Health | Operating Segments | Livestock
Segment Reporting Information [Line Items]
Sales	837	807	1,686	1,656
Animal Health | Operating Segments | Livestock | U.S.
Segment Reporting Information [Line Items]
Sales	168	165	334	338
Animal Health | Operating Segments | Livestock | Non-US
Segment Reporting Information [Line Items]
Sales	669	643	1,352	1,318
Animal Health | Operating Segments | Companion Animal
Segment Reporting Information [Line Items]
Sales	645	649	1,307	1,291
Animal Health | Operating Segments | Companion Animal | U.S.
Segment Reporting Information [Line Items]
Sales	287	310	595	618
Animal Health | Operating Segments | Companion Animal | Non-US
Segment Reporting Information [Line Items]
Sales	$ 358	$ 339	$ 712	$ 673

Segment Reporting - Consolidate

Segment Reporting - Consolidated Sales by Geographic Area (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Revenue from External Customer [Line Items]
Sales	$ 16,112	$ 15,035	$ 31,887	$ 29,522
United States
Revenue from External Customer [Line Items]
Sales	7,876	7,018	15,354	13,676
Europe, Middle East and Africa
Revenue from External Customer [Line Items]
Sales	3,515	3,348	7,078	6,651
China
Revenue from External Customer [Line Items]
Sales	1,817	1,913	3,589	3,628
Latin America
Revenue from External Customer [Line Items]
Sales	858	742	1,655	1,403
Japan
Revenue from External Customer [Line Items]
Sales	686	675	1,507	1,434
Asia Pacific (other than China and Japan)
Revenue from External Customer [Line Items]
Sales	748	848	1,472	1,694
Other
Revenue from External Customer [Line Items]
Sales	$ 612	$ 491	$ 1,232	$ 1,036

Segment Reporting - Reconciliat

Segment Reporting - Reconciliation of Segment Profits to Income before Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Segment Reporting Information [Line Items]
Profits	$ 6,006	$ (5,335)	$ 11,675	$ (1,685)
Interest income	69	109	141	221
Interest expense	(310)	(277)	(613)	(519)
Amortization			(1,087)	(1,020)
Depreciation			(1,029)	(874)
Research and development	(3,500)	(13,321)	(7,492)	(17,597)
Restructuring costs	(80)	(151)	(202)	(218)
Operating Segments
Segment Reporting Information [Line Items]
Profits	11,708	10,321	23,168	20,025
Operating Segments | Pharmaceutical segment
Segment Reporting Information [Line Items]
Profits	11,200	9,854	22,104	18,993
Operating Segments | Animal Health segment
Segment Reporting Information [Line Items]
Profits	508	467	1,064	1,032
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Profits	129	19	274	184
Interest income	69	109	141	221
Interest expense	(310)	(277)	(613)	(519)
Amortization	(614)	(477)	(1,087)	(1,020)
Depreciation	(450)	(376)	(902)	(775)
Research and development	(3,360)	(13,194)	(7,209)	(17,341)
Restructuring costs	(80)	(151)	(202)	(218)
Charge for Zetia antitrust litigation settlements	0	0	0	(573)
Other unallocated, net	$ (1,086)	$ (1,309)	$ (1,895)	$ (1,669)