The instrument defining the rights of the holders of the 3.625% Notes due 2024 is Exhibit 5 to Form 8-K, filed February 11, 2014, and is hereby incorporated by reference. The instrument defining the rights of the holders of the Floating Rate Notes due 2021 is Exhibit 2 to Form 8-K, filed November 5, 2014, and is hereby incorporated by reference. The instrument defining the rights of the holders of the 1.25% Notes due 2023 is Exhibit 2 to Form 8-K, filed November 25, 2014, and is hereby incorporated by reference. The instrument defining the rights of the holders of the 2.625% Notes due 2022 is Exhibit 2 to Form 8-K, filed on August 4, 2015, and is hereby incorporated by reference. The instrument defining the rights of the holders of the 2.875% Notes due 2022 is Exhibit 2 to Form 8-K, filed on November 6, 2015, and is hereby incorporated by reference. The instruments defining the rights of the holders of the 1.800% Notes due 2019, 2.250% Notes due 2021, 3.450% Notes due 2026 and 4.700% Notes due 2046 are Exhibits 4.2, 4.3, 4.4 and 4.5 to Form 8-K filed February 18, 2016, and are hereby incorporated by reference. The instruments defining the rights of the holders of the 0.500% Notes due 2021, 1.125% Notes due 2024 and 1.750% Notes due 2028 are Exhibits 4.1, 4.2 and 4.3 to Form 8-K filed March 4, 2016 and are hereby incorporated by reference. The instrument defining the rights of the holders of the 0.30% Notes due 2026 is Exhibit 4 to Form 8-K filed November 1, 2016 and is hereby incorporated by reference. The instruments defining the rights of the holders of the Floating Rate Notes due 2020, 1.900% Notes due 2020, 2.500% Notes due 2022 and 3.300% Notes due 2027 are Exhibits 4.1, 4.2, 4.3 and 4.4 to Form 8-K filed January 26, 2017, and are hereby incorporated by reference. The instruments defining the rights of the holders of the 0.950% Notes due 2025, and 1.500% Notes due 2029 are Exhibits 4.1 and 4.2 to Form 8-K filed May 22, 2017, and are hereby incorporated by reference. The instruments defining the rights of the holders of the 0.375% Notes due 2023, and 0.875% Notes due 2025, the 1.250% Notes due 2027 and the 1.750% Notes due 2031 are Exhibits 4.1, 4.2, 4.3 and 4.4 to Form 8-K, filed January 30, 2019, and are hereby incorporated by reference. Indenture dated as of October 1, 1993 between IBM and The Bank of New York Mellon, (as successor to The Chase Manhattan Bank (National Association)) as Trustee, is Exhibit 4.1 to Form 10-Q for the quarter ended September 30, 2017, and is hereby incorporated by reference. 24 Exhibit Number in this Form 10- K Description of Exhibits Reference Number per Item 601 of Regulation S- K