Insider Transaction of Deferred Stock Units

Cynthia Jane Comparin, a director at CULLEN/FROST BANKERS, INC. (CFR), acquired 630 Deferred Stock Units on April 29, 2026. These units, each representing one share of common stock, vested on the same date. The delivery of shares will occur upon Ms. Comparin's separation from the company. Following this transaction, she holds 5,584 Deferred Stock Units. The transaction was reported on May 27, 2026, under Form 4.