1 UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 11 - K [X] ANNUAL REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended.............December 31, 1999......................... OR [ ] TRANSITION REPORT PURSUANT TO SECTION 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from........................to........................ Commission file number............000-14824.......................[Plexus Corp.] A. Full title of the plan and the address of the plan, if different from that of the issuer named below: PLEXUS CORP. EMPLOYEE STOCK SAVINGS PLAN B. Name of issuer of the securities held pursuant to the plan and the address of its principal executive office: PLEXUS CORP. 55 JEWELERS PARK DRIVE NEENAH, WISCONSIN 54956 2 Plexus Corp. Employee Stock Savings Plan Index to Financial Statements December 31, 1999 and 1998 - -------------------------------------------------------------------------------- Page ---- Report of Independent Accountants 1 Statements of Net Assets Available for Benefits as of December 31, 1999 and 1998 2 Statement of Changes in Net Assets Available for Benefits for the year ended December 31, 1999 3 Notes to Financial Statements 4-7 Schedule Required by the Department of Labor's Rules and Regulations: * Form 5500, Schedule of Assets Held for Investment Purposes at End of Year as of December 31, 1999 8 * Other schedules required by the Department of Labor have been omitted because they are not applicable. 3 REPORT OF INDEPENDENT ACCOUNTANTS To the Participants and Administrator of the Plexus Corp. Employee Stock Savings Plan In our opinion, the accompanying statements of net assets available for benefits and the related statement of changes in net assets available for benefits present fairly, in all material respects, the net assets available for benefits of the Plexus Corp. Employee Stock Savings Plan (the "Plan") as of December 31, 1999 and 1998, and the changes in net assets available for benefits for the year ended December 31, 1999, in conformity with accounting principles generally accepted in the United States. 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 of these statements in accordance with auditing standards generally accepted in the United States, which 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, assessing the accounting principles used and significant estimates made by management, and evaluating the overall financial statement presentation. We believe that our audits provide a reasonable basis for the opinion expressed above. Our audits were conducted for the purpose of forming an opinion on the basic financial statements taken as a whole. The supplemental schedule of Assets Held for Investment Purposes at End of Year is presented for the purpose of additional analysis and is not a required part of the basic 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. This supplemental schedule is the responsibility of the Plan's management. The supplemental schedule has been subjected to the auditing procedures applied in the audits of the basic financial statements and, in our opinion, is fairly stated in all material respects in relation to the basic financial statements taken as a whole. Pricewaterhousecooper LLP Milwaukee, Wisconsin May 29, 2000 4 PLEXUS CORP. EMPLOYEE STOCK SAVINGS PLAN STATEMENTS OF NET ASSETS AVAILABLE FOR BENEFITS DECEMBER 31, 1999 AND 1998 - -------------------------------------------------------------------------------- 1999 1998 ----------- ----------- Assets Investments (See Note 3) $66,999,524 $47,616,410 ----------- ----------- Receivables: Employer's contribution 53,397 43,294 Participants' contributions 161,158 123,425 ----------- ----------- Total receivables 214,555 166,719 ----------- ----------- Net assets available for benefits $67,214,079 $47,783,129 =========== =========== The accompanying notes are an integral part of these financial statements. - 2 - 5 PLEXUS CORP. EMPLOYEE STOCK SAVINGS PLAN STATEMENT OF CHANGES IN NET ASSETS AVAILABLE FOR BENEFITS FOR THE YEAR ENDED DECEMBER 31, 1999 - -------------------------------------------------------------------------------- Additions Additions to net assets attributed to: Investment income: Net appreciation in fair value of investments $14,297,834 Interest 102,102 ----------- 14,399,936 ----------- Contributions: Participants' 4,169,612 Employer's 1,302,957 ----------- 5,472,569 ----------- Total additions 19,872,505 Deductions Deductions from net assets attributed to: Benefits paid to participants 1,945,400 ----------- Net increase before plan transfer 17,927,105 Transfer from another plan 1,503,845 ----------- Net increase 19,430,950 Net assets available for benefits: Beginning of year 47,783,129 ----------- End of year $67,214,079 =========== The accompanying notes are an integral part of these financial statements. - 3 - 6 PLEXUS CORP. EMPLOYEE STOCK SAVINGS PLAN NOTES TO FINANCIAL STATEMENTS DECEMBER 31, 1999 AND 1998 1. DESCRIPTION OF PLAN The following description of the Plexus Corp. Employee Stock Savings Plan (the "Plan") provides only general information. Participants should refer to the plan agreement for a more complete description of the Plan's provisions. GENERAL The Plan, effective January 1, 1989, is a contributory defined contribution plan covering all employees of Plexus Corp. (the "Company") who have completed 90 days of service. The Plan is subject to the provisions of the Employee Retirement Income Security Act of 1974 ("ERISA"). CONTRIBUTIONS Employee pre-tax contributions are based on voluntary written elections by the participants directing the Company to defer a stated amount from the participant's compensation. Participants may elect to defer up to 15% of their annual compensation. The Company will make a matching contribution on behalf of a participant equal to 100% of the first 2.5% of the participant's elective deferrals for participants who have completed one year of service. Substantially all Company matching contributions are allocated to the Employer Stock Fund. Contributions are limited by Section 401(k) of the Internal Revenue Code. INVESTMENT ALTERNATIVES Plan participants may direct their entire account balances in 1% increments to any of various investment options offered by the Plan. Participants may change their investment options on a daily basis. PARTICIPANT ACCOUNTS AND ALLOCATIONS Each participant's account is credited with the participant's contributions and allocations of Company contributions and plan earnings. Allocations of plan earnings are based on participant account balances in relation to total fund account balances, as defined by the plan document. Participants in the Plexus Unitized Stock Fund are allocated an undivided interest in the shares held by the fund. VESTING AND DISTRIBUTIONS Participants immediately vest in all contributions made to the Plan. Participant accounts are distributable in the form of a lump sum payment of cash or in whole shares of Company securities as elected by the participant upon retirement, termination of employment, death, disability, financial hardship or attainment of age 59-1/2. In addition, participant accounts can be rolled over into an individual retirement account ("IRA") or another qualified defined contribution plan. Participant distributions may not be deferred past April 1 of the calendar year following the year in which the participant attains age 70-1/2. Forfeitures of unclaimed distributions are used to reduce Company matching contributions. - 4 - 7 PLEXUS CORP. EMPLOYEE STOCK SAVINGS PLAN NOTES TO FINANCIAL STATEMENTS DECEMBER 31, 1999 AND 1998 2. SUMMARY OF ACCOUNTING POLICIES ACCOUNTING METHOD The financial statements of the Plan are prepared under the accrual method of accounting. USE OF ESTIMATES The preparation of financial statements in conformity with generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, and changes therein, and disclosure of contingent assets and liabilities. Actual results could differ from those estimates. INVESTMENT VALUATION AND INCOME RECOGNITION Investments are stated at fair value based on the quoted asset values on the last business day of the plan year. The Plan presents in the statement of changes in net assets available for benefits, the net appreciation in the fair value of its investments which consists of the realized gains or losses and the unrealized appreciation (depreciation) on those investments. RISKS AND UNCERTAINTIES The Plan's investments are exposed to various risks, such as interest rate, market, and credit risks. Due to the level of risk associated with certain investments and the level of uncertainty related to changes in the values of investments, it is at least reasonably possible that changes in risks in the near term would materially affect participants' account balances and the amounts reported in the statements of net assets available for benefits and the statement of changes in net assets available for benefits. PAYMENT OF BENEFITS Benefits are recorded when paid. ADMINISTRATIVE EXPENSES Certain expenses incurred in the administration of the Plan are paid by the Company and are not reflected within these financial statements. - 5 - 8 PLEXUS CORP. EMPLOYEE STOCK SAVINGS PLAN NOTES TO FINANCIAL STATEMENTS DECEMBER 31, 1999 AND 1998 3. INVESTMENTS The following presents investments that represent 5 percent or more of the Plan's net assets: December 31, ------------------------- 1999 1998 --------- --------- Plexus Unitized Stock Fund, 1,098,792 and 1,112,208 shares, respectively $34,636,129 $27,167,894 Oppenheimer Quest Opportunity Value Fund, 121,757 and 97,838 shares, respectively 4,195,738 3,517,266 Munder Index 500 Fund, 207,882 and 149,662 shares, respectively 6,436,031 3,928,634 AIM Value Fund, 127,871 and 89,090 shares, respectively 6,243,961 3,580,541 AIM Constellation Fund, 134,152 and 96,018 shares, respectively 5,434,524 2,930,476 American EuroPacific Growth Fund, 96,350 and 70,762 shares, respectively 4,110,276 2,009,632 During 1999, the Plan's investments (including gains and losses on investments bought and sold, as well as held during the year) appreciated in value by $14,297,834 as follows: Mutual funds $ 5,759,055 Common stock 8,538,779 ------------ $ 4,297,834 ============ 4. AMOUNTS ALLOCATED TO WITHDRAWN PARTICIPANTS Approximately $3,214,907 of plan assets have been allocated to the accounts of persons who are no longer active participants of the Plan as of December 31, 1999, but who have not yet received distributions as of that date. 5. TAX STATUS The Internal Revenue Service has determined and informed the Company by a letter dated May 6, 1998, that the Plan is designed in accordance with applicable sections of the Internal Revenue Code. - 6 - 9 PLEXUS CORP. EMPLOYEE STOCK SAVINGS PLAN NOTES TO FINANCIAL STATEMENTS DECEMBER 31, 1999 AND 1998 6. PLAN TERMINATION Although it has not expressed any intent to do so, the Company has the right under the Plan to discontinue its contributions at any time and to terminate the Plan subject to the provisions of ERISA. 7. RELATED PARTY TRANSACTIONS Certain plan investments represent shares of employer securities and participant loans. These transactions are considered party-in-interest transactions. These transactions are not, however, considered prohibited transactions under 29 CFR 408(b) of the ERISA regulations. 8. SUBSEQUENT EVENT Effective March 1, 2000, the SeaMed Corporation Employee Savings Plan (the "SeaMed Plan") merged into the Plan. Additionally, the Plan's name changed to Plexus Corp. 401(k) Savings Plan on that date. - 7 - 10 PLEXUS CORP. EMPLOYEE STOCK SAVINGS PLAN FORM 5500, SCHEDULE OF ASSETS HELD FOR INVESTMENT PURPOSES AT END OF YEAR DECEMBER 31, 1999 Identity of Issuer, Borrower, Lessor Current or Similar Party Description of Investment Value ------------------------- ------------------------- ------------- (*) Plexus Unitized Stock Fund Plexus Corp. Common Stock $ 34,636,129 Ivy Money Market Fund Mutual Fund 2,339,151 Ivy Bond Fund Mutual Fund 870,277 Oppenheimer Quest Opportunity Value Fund Mutual Fund 4,195,738 Munder Index 500 Fund Mutual Fund 6,436,031 AIM Value Fund Mutual Fund 6,243,961 American EuroPacific Growth Fund Mutual Fund 4,110,276 AIM Constellation Fund Mutual Fund 5,434,524 Seligman Frontier Fund Mutual Fund 2,394,933 American Balanced Fund Mutual Fund 261,762 (*) Participant Loans Interest rates ranging from 8.2% to 24.0%; Maturity dates ranging from 2000 to 2004 76,742 ------------- $ 66,999,524 ============= * Party-in-interest transactions. - 8 - 11 SIGNATURES The Plan. 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. PLEXUS CORP. EMPLOYEE STOCK SAVINGS PLAN Date: June 26, 2000 /s/ Jos. D. Kaufman ------------------- Joseph D. Kaufman Employee Stock Savings Plan Fiduciary Committee Member