First Merchants Corporation

Item 1.01. Entry into a Material Definitive Agreement. Pursuant to the previously announced offering of $100 million aggregate principal amount of 6.750% Fixed-to-Floating Rate Subordinated Notes due 2036 (the “Notes”) to be issued by First Merchants Corporation, an Indiana corporation (the “Corporation”), the Corporation and U.S. Bank Trust Company, National Association, as trustee, entered into an Indenture dated as of September 25, 2026 (the “Base Indenture”) and a First Supplemental Indenture dated as of September 25, 2026 to the Base Indenture (the “Supplemental Indenture” and, together with the Base Indenture, the “Indenture”), providing for the issuance of the Notes. The Notes bear interest at an initial rate of 6.750% per annum, payable semi-annually in arrears on April 1 and October 1 of each year, commencing on April 1, 2027. From and including October 1, 2031 to, but excluding, October 1, 2036 (unless redeemed prior to such date), the Notes will bear interest at a floating rate per annum equal to a benchmark rate (reset quarterly) (which is expected to be Three-Month Term SOFR) plus 202 basis points, payable quarterly in arrears on January 1, April 1, July 1, and October 1 of each year, commencing on January 1, 2032. Notwithstanding the foregoing, if the benchmark is less than zero, the benchmark will be deemed to be zero. The Notes will mature on October 1, 2036, unless earlier redeemed. The Notes may be redeemed at the Corporation’s option, beginning on October 1, 2031, and on any interest payment date thereafter, in whole or in part, at a redemption price equal to 100% of the principal amount of the Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the date of redemption. Any partial redemption will be made in accordance with the applicable procedures of The Depository Trust Company. The Notes may also be redeemed, at any time prior to their maturity including prior to October 1, 2031, in whole, but not in part, subject to obtaining the prior approval of the Federal Reserve to the extent such approval is then required under the rules of the Federal Reserve, upon or after the occurrence of (i) a Tax Event (as defined in the Indenture); (ii) a subsequent event, as a result of which there is more than an insubstantial risk that the Corporation would not be entitled to treat the Notes as Tier 2 capital for regulatory capital purposes; or (iii) a requirement that the Corporation register as an investment company under the Investment Company Act of 1940. In each case, the redemption would be at a redemption price equal to 100% of the principal amount of the Notes plus any accrued and unpaid interest to but excluding the redemption date. The foregoing summaries of the Base Indenture, the Supplemental Indenture, and the Notes, respectively, are not complete and are each qualified in their entirety by reference to the complete text of the respective documents (or, in the case of the Notes, the form thereof), each of which is attached hereto as Exhibits 1.1, 4.1, 4.2, and 4.3, respectively, to this Current Report on Form 8-K and incorporated herein by reference in their entirety. The above-mentioned offering was made pursuant to an effective shelf registration statement on Form S-3ASR (File No. 333-298983) filed by the Corporation. A copy of the opinion of Dentons Bingham Greenebaum LLP relating to the legality of the Notes is filed as Exhibit 5.1 to this Current Report on Form 8-K.

Item 2.03. Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant. The disclosures above under Item 1.01 of this Current Report on Form 8-K are also responsive to Item 2.03 of this Current Report on Form 8-K and are hereby incorporated by reference into this Item 2.03. - 2 -