UNITED STATES
 SECURITIES AND EXCHANGE COMMISSION
 Washington, D.C. 20549
 Form 10-K/A
 (Amendment No. 1)
 (Mark One)
 ☒ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
 For the fiscal year ended December 31, 2019
 or
 ☐TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
 Commission file number 001-37702
 Amgen Inc.
 (Exact name of registrant as specified in its charter)
 Delaware95-3540776(State or other jurisdiction ofincorporation or organization)(I.R.S. EmployerIdentification No.)One Amgen Center Drive91320-1799Thousand OaksCalifornia(Address of principal executive offices)(Zip Code)
 ( 805 ) 447-1000
 (Registrant’s telephone number, including area code)
 Securities registered pursuant to Section 12(b) of the Act:
 Title of each classTrading Symbol (s)Name of each exchange on which registeredCommon stock, $0.0001 par valueAMGNThe NASDAQ Global Select Market1.250% Senior Notes Due 2022AMGN22New York Stock Exchange2.00% Senior Notes Due 2026AMGN26New York Stock Exchange
 Securities registered pursuant to Section 12(g) of the Act: None
 Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.  Yes  ý No  ̈
 Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.  Yes  ̈  No  ý
 Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or Section 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.  Yes  ý No  ̈
 Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).  Yes  ý No  ̈
 Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.
 Large accelerated filerAccelerated filerNon-accelerated filerSmaller reporting companyEmerging growth company☒☐☐☐☐
 If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.  ̈
 Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act)  Yes ☐ No ý
 
 The approximate aggregate market value of voting and non-voting stock held by non-affiliates of the registrant was $110,809,019,075 as of June 30, 2019 . (A)
 
 (A)Excludes744,928shares of common stock held by directors and executive officers, and any stockholders whose ownership exceeds ten percent of the shares outstanding, at June 30, 2019. Exclusion of shares held by any person should not be construed to indicate that such person possesses the power, directly or indirectly, to direct or cause the direction of the management or policies of the registrant, or that such person is controlled by or under common control with the registrant. 589,806,819
 (Number of shares of common stock outstanding as of February 6, 2020 )
 
 DOCUMENTS INCORPORATED BY REFERENCE
 Specified portions of the registrant’s Proxy Statement with respect to the 2020 Annual Meeting of Stockholders to be held May 19, 2020, are incorporated by reference into Part III of this annual report.
 
 
   
 
 
 EXPLANATORY NOTE
 This Amendment No.1 to the Annual Report on Form 10-K of Amgen Inc. (the Company) for the year ended December 31, 2019 as filed with the Securities and Exchange Commission on February 12, 2020 (the Original Form 10-K), is being filed for the sole purpose of inserting the conformed signature of Ernst & Young LLP, the Company’s independent auditor, which was inadvertently omitted from the Original Form 10-K.
 Except as otherwise expressly noted herein, this Amendment No. 1 does not modify or update in any way the financial position, results of operations, cash flows, or other disclosures in, or exhibits to, the Original Form 10-K, nor does it reflect events occurring after the filing of the Original Form 10-K. Accordingly, this Amendment No. 1 should be read in conjunction with the Original Form 10-K.
 
   
 
 
 INDEX TO EXHIBITS
 Exhibit No.Description31Rule 13a-14(a) Certifications.32Section 1350 Certifications.
 
 
   
 
 
 Report of Independent Registered Public Accounting Firm
 To the Board of Directors and Stockholders of Amgen Inc.
 Opinion on the Financial Statements
 We have audited the accompanying consolidated balance sheets of Amgen Inc. (the Company) as of December 31, 2019 and 2018, the related consolidated statements of income, comprehensive income, stockholders’ equity and cash flows for each of the three years in the period ended December 31, 2019, and the related notes and the financial statement schedule listed in the Index at Item 15(a)2 (collectively referred to as the “consolidated financial statements”). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company at December 31, 2019 and 2018, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2019, in conformity with U.S. generally accepted accounting principles.
 We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the Company’s internal control over financial reporting as of December 31, 2019, based on criteria established in Internal Control-Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (2013 framework) and our report dated February 12, 2020 expressed an unqualified opinion thereon.
 Basis for Opinion
 These financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on the Company’s financial statements based on our audits. We are a public accounting firm registered with the PCAOB and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.
 We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion.
 Critical Audit Matters
 The critical audit matters communicated below are matters arising from the current period audit of the financial statements that were communicated or required to be communicated to the audit committee and that: (1) relate to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the financial statements, taken as a whole, and we are not, by communicating the critical audit matters below, providing separate opinions on the critical audit matters or on the accounts or disclosures to which they relate.
 
 F-1
  
 
 Sales deductionsDescription of the MatterAs of December 31, 2019, the Company recorded accrued sales deductions of $3.9 billion. As described in Note 1 to the financial statements under the caption “Product sales and sales deductions,” revenues from product sales are recognized net of accruals for estimated rebates, wholesaler chargebacks, discounts and other deductions, (collectively sales deductions), which are established at the time of sale.Auditing the estimation of sales deductions, which are netted against product sales, is complex, requires significant judgment, and the amounts involved are material to the financial statements taken as a whole. Revenue from product sales is recognized upon transfer of control of a product to a customer, generally upon delivery, and is based on an amount that reflects the consideration to which the Company expects to be entitled, which represents an amount that is net of accruals for estimated sales deductions. The estimated sales deductions are based on current contractual and statutory requirements, market events and trends, internal and external historical data, and forecasted customer buying patterns.How We Addressed the Matter in Our AuditWe obtained an understanding, evaluated the design and tested the operating effectiveness of internal controls over the sales deduction processes. This included testing controls over management’s review of significant assumptions and inputs used in the estimate of sales deductions, including actual sales, contractual terms, historical experience, wholesaler inventory levels, demand data and estimated patient population. We also tested management’s controls over the accuracy of forecasting demand activity as well as the completeness and accuracy of all other components included in the final sales deduction estimates.To test management’s estimated sales deductions, we obtained management’s calculations for the respective estimates and performed the following procedures, among others. We tested management’s estimation process over the determination of sales discount accruals by developing an independent expectation of the estimated accrual rate, including a comparison of rates used in management’s forecast to rates in the underlying contracts, performing a lookback analysis using actual historical data to evaluate the forecasted amounts, assessing subsequent events to determine whether there was any new information that would require adjustment to the initial accruals, evaluating trends in actual sales and discount accrual balances, comparing cash receipts to product sales, confirming terms and conditions for a sample of contracts with the Company’s customers, testing a sample of credits issued and payments made throughout the year, and agreeing rates to underlying contract terms.
 
 
 F-2
  
 
 Unrecognized Tax BenefitsDescription of the MatterAs discussed in Notes 1 and 6 to the consolidated financial statements, the Company operates in various jurisdictions in which differing interpretations of complex tax laws and regulations create uncertainty and necessitate the use of significant judgment in the determination of the Company’s unrecognized tax benefits related to allocation of profits among various jurisdictions (“transfer pricing”), particularly in the U.S. federal tax jurisdiction where the Company has significant assets and operations. In this regard, the Company uses significant judgment in (1) determining whether a tax position’s technical merits are more-likely-than-not to be sustained and (2) measuring the amount of tax benefit that qualifies for recognition. As of December 31, 2019, the Company accrued $3.3 billion of gross unrecognized tax benefits including transfer pricing. Auditing the assessment of the technical merits and measurement of the Company’s unrecognized tax benefits is challenging because they can be complex, highly judgmental, and based on interpretations of tax laws and regulations.How We Addressed the Matter in Our AuditWe obtained an understanding, evaluated the design and tested the operating effectiveness of internal controls over the Company’s process to assess the technical merits of its tax positions, as well as management’s process to measure the unrecognized tax benefits of those tax positions, particularly in regard to transfer pricing. This included testing controls over management’s review of the inputs, calculations, assumptions and methods selected to measure the amount of tax benefits that qualify for recognition.We involved tax and transfer pricing professionals to assist in assessing the technical merits and measurement of certain of the Company’s unrecognized tax benefits. Depending on the nature of the specific tax position and, as applicable, developments with the relevant tax authorities, our procedures included obtaining and reviewing the Company’s correspondence with such tax authorities and evaluating certain third-party advice to support the Company’s evaluations and recorded positions. We used our knowledge of and experience with how the income tax laws and regulations related to transfer pricing are applied by the relevant tax authorities to evaluate the Company’s accounting for its unrecognized tax benefits. We evaluated developments in the applicable regulatory environments to assess potential effects on the Company’s recorded positions. We analyzed the assumptions and data used by the Company when it determined the amount of tax benefits to recognize, including applicable interest and penalties, and we tested the accuracy of those underlying calculations. We have also evaluated the Company’s income tax disclosures included in Note 6 in relation to these matters.
 
 /s/ Ernst & Young LLP
 
 We have served as the Company’s auditor since 1980.
 Los Angeles, California
 February 12, 2020
 
 
 F-3
  
 
 
 SIGNATURES
 Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this Annual Report to be signed on its behalf by the undersigned, thereunto duly authorized.
 AMGEN INC.(Registrant)Date:February 13, 2020By:/S/    PETER H. GRIFFITHPeter H. GriffithExecutive Vice President and Chief Financial Officer(Principal Financial and Accounting Officer)