UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FOR THE YEAR ENDED DECEMBER 31, 2018 ANNUAL REPORT pursuant to Section 13 or 15 (d) of the Securities Exchange Act of 1934 1-2360 (Commission file number) 13-0871985 (IRS Employer Identification Number) 10504 (Zip Code) NEW YORK (State of Incorporation) ARMONK, NEW YORK (Address of principal executive offices) 914-499-1900 (Registrant's telephone number) Title of each class Voting shares outstanding at February 8, 2019 Name of each exchange on which registered Capital stock, par value $.20 per share 889,866,256 New York Stock Exchange Chicago Stock Exchange 1.375% Notes due 2019 New York Stock Exchange 2.750% Notes due 2020 New York Stock Exchange 1.875% Notes due 2020 New York Stock Exchange 0.500% Notes due 2021 New York Stock Exchange 2.625% Notes due 2022 New York Stock Exchange 1.25% Notes due 2023 New York Stock Exchange 0.375% Notes due 2023 New York Stock Exchange 1.125% Notes due 2024 New York Stock Exchange 2.875% Notes due 2025 New York Stock Exchange 0.950% Notes due 2025 New York Stock Exchange 0.875% Notes due 2025 New York Stock Exchange 0.300% Notes due 2026 New York Stock Exchange 1.250% Notes due 2027 New York Stock Exchange 1.750% Notes due 2028 New York Stock Exchange 1.500% Notes due 2029 New York Stock Exchange 1.750% Notes due 2031 New York Stock Exchange 8.375% Debentures due 2019 New York Stock Exchange 7.00% Debentures due 2025 New York Stock Exchange 6.22% Debentures due 2027 New York Stock Exchange 6.50% Debentures due 2028 New York Stock Exchange 7.00% Debentures due 2045 New York Stock Exchange 7.125% Debentures due 2096 New York Stock Exchange Securities registered pursuant to Section 12(b) of the Act: 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 o 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 o No ý Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 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 o 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 o Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K (§229.405 of this chapter) is not contained herein, and will not be contained, to the best of registrant's knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K. o 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 filer ý  Non-accelerated filer o Accelerated filer o Smaller reporting company o Emerging growth company o 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. o Indicate by check mark whether the registrant is a shell company (as defined in Exchange Act Rule 12b-2). Yes o No ý The aggregate market value of the voting stock held by non-affiliates of the registrant as of the last business day of the registrant's most recently completed second fiscal quarter was $127.5 billion. Portions of IBM's Annual Report to Stockholders for the year ended December 31, 2018 are incorporated by reference into Parts I, II and IV of this Form 10-K. Portions of IBM's definitive Proxy Statement to be filed with the Securities and Exchange Commission and delivered to stockholders in connection with the Annual Meeting of Stockholders to be held April 30, 2019 are incorporated by reference into Part III of this Form 10-K. Documents incorporated by reference: FORM 10-K INTERNATIONAL BUSINESS MACHINES CORPORATION (Exact name of registrant as specified in its charter) 10-K 1 a2237254z10-k.htm 10-K  QuickLinks  -- Click here to rapidly navigate through this document