UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON D.C. 20549 FORM 11-K (Mark One) [X] ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2000 OR [_] TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission file number 000-12477 AMGEN RETIREMENT AND SAVINGS PLAN (Full title of the plan) AMGEN INC. (Name of issuer of the securities held) One Amgen Center Drive, Thousand Oaks, California 91320-1799 (Address of principal executive offices) (Zip Code)

Amgen Retirement and Savings Plan Financial Statements and Supplemental Schedule Years ended December 31, 2000 and 1999 Contents Report of Independent Auditors............................................ 1 Audited Financial Statements Statements of Net Assets Available for Benefits........................... 2 Statements of Changes in Net Assets Available for Benefits................ 3 Notes to Financial Statements............................................. 4 Supplemental Schedule Schedule of Assets (Held at End of Year).................................. 9

Report of Independent Auditors Amgen Inc., as Named Fiduciary, and the Plan Participants of the Amgen Retirement and Savings Plan We have audited the accompanying statements of net assets available for benefits of the Amgen Retirement and Savings Plan as of December 31, 2000 and 1999, and the related statements of changes in net assets available for benefits for the years then ended. These financial statements are the responsibility of the Plan's management. Our responsibility is to express an opinion on these financial statements based on our audits. We conducted our audits in accordance with auditing standards generally accepted in the United States. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement. An audit includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements. An audit also includes assessing the accounting principles used and significant estimates made by management, as well as evaluating the overall financial statement presentation. We believe that our audits provide a reasonable basis for our opinion. In our opinion, the financial statements referred to above present fairly, in all material respects, the net assets available for benefits of the Plan at December 31, 2000 and 1999, and the changes in its net assets available for benefits for the years then ended in conformity with accounting principles generally accepted in the United States. Our audits were performed for the purpose of forming an opinion on the financial statements taken as a whole. The accompanying supplemental schedule of assets (held at end of year) as of December 31, 2000, is presented for purposes of additional analysis and is not a required part of the financial statements but is supplementary information required by the Department of Labor's Rules and Regulations for Reporting and Disclosure under the Employee Retirement Income Security Act of 1974. The supplemental schedule is the responsibility of the Plan's management. The supplemental schedule has been subjected to the auditing procedures applied in our audits of the financial statements and, in our opinion, is fairly stated in all material respects in relation to the financial statements taken as a whole. /s/ Ernst & Young LLP May 31, 2001 Los Angeles, California 1

Amgen Retirement and Savings Plan Statements of Net Assets Available for Benefits December 31 2000 1999 ------------------------------------ Assets Investments at fair value $727,246,010 $694,704,196 Contributions receivable - 1,959,018 Accrued interest and dividends - 24,232 ------------------------------------ Net assets available for benefits $727,246,010 $696,687,446 ==================================== See accompanying notes. 2

Amgen Retirement and Savings Plan Statements of Changes in Net Assets Available for Benefits Year ended December 31 2000 1999 -------------------------- Additions to net assets: Employee contributions $ 46,797,803 $ 34,456,717 Employer contributions 33,796,325 25,751,763 Interest and dividend income 44,070,900 31,970,804 Realized/unrealized gain - 178,969,323 ------------- ------------ Total additions 124,665,028 271,148,607 Deductions from net assets: Benefits paid 22,246,707 15,065,459 Realized/unrealized loss 71,859,757 - ------------- ------------ Total deductions 94,106,464 15,065,459 ------------- ------------ Net increase 30,558,564 256,083,148 Net assets available for benefits at beginning of year 696,687,446 440,604,298 ------------- ------------ Net assets available for benefits at end of year $727,246,010 $696,687,446 ============= ============ See accompanying notes. 3

Amgen Retirement and Savings Plan Notes to Financial Statements December 31, 2000 1. Description of Plan The following description of the Amgen Retirement and Savings Plan (the Plan) provides only general information. Participants should refer to the Plan document for a more complete description of the Plan's provisions. General The Plan was established effective April 1, 1985 (amended and restated effective January 1, 1990, January 1, 1993, April 1, 1996 and October 23, 2000, respectively), as a defined contribution plan covering substantially all domestic employees of Amgen Inc. (the Company). It is subject to the provisions of the Employee Retirement Income Security Act of 1974 (ERISA). Contributions Participants may elect to contribute up to 15% of their pretax annual compensation (a maximum contribution of $10,500 and $10,000 in 2000 and 1999, respectively). Participants may also contribute amounts representing distributions from other qualified defined benefit or defined contribution plans. The Company makes matching contributions of up to 100% of the first 5% of eligible salary contributed by the employee per pay period. In addition, the Company supplements the above contribution for all eligible employees, whether or not they have elected to make contributions to the Plan, with a Core contribution equal to 3% of each eligible employee's compensation each pay period. Participants select the funds in which their contributions are to be invested, electing among various investment alternatives. Participants may elect for their contributions to be invested in more than one fund; however, no more than 50% of their total contributions may be invested in the Amgen Inc. Stock Fund. Participants may change their investment options at any time. Vesting Participants are immediately vested with respect to their individual contributions and earnings thereon. Participants become vested in their allocated Company matching contributions and related earnings at a rate of 25% per year for each of their first four years of service completed. 4

Amgen Retirement and Savings Plan Notes to Financial Statements (continued) 1. Description of Plan (continued) Vesting (continued) The Company Core contributions and related earnings become 100% vested upon completion of five years of service, with no partial vesting. Generally, employees must work a minimum of 1,000 hours within a Plan year to receive vesting for that year of service. Company contributions become fully vested upon attainment of normal retirement age, disability or death. Participant Accounts Each participant's account is credited with the participant's contributions and an allocation of (a) Company contributions and (b) Plan earnings. The benefit to which a participant is entitled is the vested portion of the participant's account. Forfeited balances of terminated participants' nonvested accounts are used to reduce future Company contributions. Payments of Benefits Upon termination of service due to death, disability (as defined by the Plan) or retirement, a participant may elect to receive an amount equal to the value of the participant's vested account balance in either a lump-sum payment in cash and/or shares of the Company's common stock. The number of shares of Company common stock to be paid is based on the quoted market value of such stock on the date the Plan is valued following employee notification. Participants hired before April 1, 1996, may also elect to have an insurance annuity contract purchased on the participant's behalf. Certain restrictions apply to withdrawals of amounts from the Plan while a participant continues to be employed by the Company. Participant Loans Loans can be made to a participant generally up to the lesser of an amount equal to 50% of the participant's vested account balance or $50,000, less any outstanding loans. The loans bear interest at average borrowing rates of certain major banks (ranging from 7.08% to 11.87%) and are generally payable in installments over periods ranging from one to five years. Principal and interest payments are allocated to the participant's account. 5

Amgen Retirement and Savings Plan Notes to Financial Statements (continued) 1. Description of Plan (continued) Plan Termination Although it has not expressed any intent to do so, the Company has the right under the Plan to terminate the Plan subject to the provisions of ERISA. In the event of termination, participants will become 100% vested in their accounts. Trustee Fidelity Management Trust Company acts as the Plan's trustee. 2. Summary of Significant Accounting Policies Basis of Accounting The financial statements have been prepared on the accrual basis of accounting. Reclassification Certain amounts in the 1999 financial statements have been reclassified to conform to the 2000 presentation. Investment Income Dividend income is recognized on the ex-dividend date and interest income is recorded on an accrual basis. Unrealized gains and losses on investments are measured by the change in the difference between the fair value and cost of the securities held at the beginning and end of the period. Realized gains and losses from security transactions are recorded based on the weighted-average cost of securities sold. Investment Valuation Investments in mutual funds and Amgen Inc. common stock are valued at current market values determined through reference to public market information on the last business day of the Plan year. Participant loans are valued at their outstanding balances which approximate fair value. 6

Amgen Retirement and Savings Plan Notes to Financial Statements (continued) 2. Summary of Significant Accounting Policies (continued) Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. 3. Investments The fair value of individual investments that represent 5% or more of the Plan's net assets is as follows: December 31 2000 1999 ------------------------------ Amgen Inc. Stock Fund $ 257,843,222 $ 231,234,930 Fidelity Magellan Fund 110,689,139 113,828,967 Fidelity Growth and Income Portfolio 79,446,064 82,202,660 Fidelity OTC Portfolio 56,319,408 57,066,911 Fidelity Spartan U.S. Equity Index 50,730,271 52,567,255 Fidelity Overseas Fund 33,316,041 35,396,995 During 2000 and 1999, the Plan's investments (including gains and losses on investments bought and sold, as well as held during the year) depreciated in value by $71,859,757 in 2000 and appreciated in value by $178,969,323 in 1999, as follows: Year ended December 31 2000 1999 ------------------------------ Amgen Inc. Stock Fund $ 16,208,146 $ 127,089,607 Mutual funds (88,067,903) 51,879,716 -------------- ------------- $ (71,859,757) $ 178,969,323 ============== ============= 7

Amgen Retirement and Savings Plan Notes to Financial Statements (continued) 4. Income Tax Status The Plan has received a determination letter from the Internal Revenue Service dated July 23, 1997, stating that the Plan is qualified, in form, under Section 401(a) of the Internal Revenue Code (the Code) and, therefore, the related trust is exempt from taxation. Once qualified, the Plan is required to operate in conformity with the Code to maintain its qualification. The Company believes the Plan is being operated in compliance with the applicable requirements of the Code and, therefore, believes that the Plan is qualified and the related trust is tax exempt. Subsequent amendments have been structured to, and are intended to, maintain the Plan's tax qualified status. 5. Services Provided by the Company The Company provides certain administrative and recordkeeping services for the Plan at no cost to the Plan participants. In addition, the Company has paid the trustee fees and other related costs on behalf of the Plan. 8

Supplemental Schedule Amgen Retirement and Savings Plan EIN: 95-3540776 Plan: 35274 Schedule H, line 4i - Schedule of Assets (Held at End of Year) December 31, 2000 Description of Current Identity of Issue Investment Value -------------------------------------------------------------------------------------------------------------- Amgen Inc.* Common stock 3,979,274 shares $ 257,843,222 Fidelity Magellan Fund* Mutual fund 927,821 shares 110,689,139 Fidelity Growth and Income Portfolio* Mutual fund 1,887,079 shares 79,446,064 Fidelity Retirement Money Market Portfolio* Money market portfolio 32,649,585 Fidelity Overseas Fund* Mutual fund 969,334 shares 33,316,041 Fidelity Spartan U.S. Equity Index* Mutual fund 1,083,748 shares 50,730,271 Fidelity Short-Term Bond* Mutual fund 1,121,277 shares 9,665,412 Fidelity OTC Portfolio* Mutual fund 1,371,970 shares 56,319,408 Fidelity Asset Manager* Mutual fund 858,751 shares 14,444,193 Fidelity Asset Manager: Growth* Mutual fund 1,387,811 shares 22,080,079 Fidelity Asset Manager: Income* Mutual fund 320,144 shares 3,755,294 Fidelity U.S. Bond Index Portfolio* Mutual fund 572,295 shares 6,060,611 Fidelity Contrafund* Mutual fund 692,678 shares 34,059,016 Neuberger Berman Genesis Trust Mutual fund 179,623 shares 4,804,921 Participant loans* Interest rates from 7.08% to 11.87% 11,382,754 --------------- $ 727,246,010 =============== *Party-in-interest. 9

SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the trustees (or other persons who administer the employee benefit plan) have duly caused this annual report to be signed on its behalf by the undersigned hereunto duly authorized. Amgen Retirement and Savings Plan (Name of Plan) Date: 6/18/01 By: /s/ Barry D. Schehr --------------------- -------------------------------- Barry D. Schehr Vice President, Financial Operations, and Chief Accounting Officer Amgen Inc.

AMGEN RETIREMENT AND SAVINGS PLAN INDEX TO EXHIBIT Consent of Ernst & Young LLP, Independent Auditors Exhibit 1

EXHIBIT 1 CONSENT OF ERNST & YOUNG LLP, INDEPENDENT AUDITORS We consent to the incorporation by reference in the Registration Statement (Form S-8 No. 33-39104) pertaining to the Amgen Retirement and Savings Plan of our report dated May 31, 2001, with respect to the financial statements and supplemental schedule of the Amgen Retirement and Savings Plan included in this Annual Report (Form 11-K) for the year ended December 31, 2000. /s/ Ernst & Young LLP Los Angeles, California June 18, 2001