Cullen/Frost Bankers Director Jeffrey Rummel Receives 630 Deferred Stock Units

This Form 4 filing reports that Jeffrey M. Rummel, a director of Cullen/Frost Bankers, Inc., acquired 630 deferred stock units on April 29, 2026. Each deferred stock unit represents the right to receive one share of Cullen/Frost Bankers common stock. The units vested on the transaction date, but shares will only be delivered to Mr. Rummel upon his separation from service with the company. The transaction involved no monetary consideration, with a price per share of $0.00. Following this acquisition, Mr. Rummel holds 630 deferred stock units. The filing was signed on May 27, 2026, by Kirsten T. Irwin under power of attorney on behalf of Mr. Rummel.