Management Change/Compensation (Form 8-K)

Aircraft Time Sharing Agreement

On December 23, 2025, Simmons First National Corporation ("Company") and George Makris, Jr., the Company's chairman and chief executive officer, entered into an aircraft time sharing agreement ("Agreement") pursuant to which Mr. Makris, Jr. may lease the Company aircraft with flight crew on a non-exclusivebasis for personal travel for him and his guests subject to him reimbursing the Company for the actual expenses of such flight as further specified and listed in the Agreement (including the costs of any related "deadhead" flights). The Agreement may be terminated by either party by giving the other party 10 business days' prior written notice. The Company will not provide tax reimbursements to Mr. Makris, Jr. for any taxes arising from imputed income relating to his use of the Company aircraft for personal travel by him or his guests, or for any federal air transportation excise tax due under the Agreement.

The foregoing description of the Agreement does not purport to be complete and is qualified in its entirety by reference to the complete text of the Agreement, which is attached as Exhibit 10.1 to this Current Report on Form 8-Kand incorporated by reference herein.