PROSPERITY BANCSHARES, INC.® COMPLETES MERGER WITH AMERICAN BANK HOLDING CORPORATION

Core Viewpoint - Prosperity Bancshares, Inc. has successfully completed the merger with American Bank Holding Corporation, effective January 1, 2026, enhancing its market presence in Texas [1]. Group 1: Merger Details - The merger agreement involved Prosperity issuing 4,439,981 shares of common stock to former shareholders and award holders of American [2]. - American Bank operated 18 banking offices and 2 loan production offices in South and Central Texas, which will continue to operate under the American Bank name until the operational integration scheduled for September 2026 [4]. Group 2: Leadership Changes - Stephen Raffaele, former Director and President of American, has joined Prosperity Bank as South Texas and San Antonio Area Chairman, while Ben Wallace, former Chairman of American Bank, has taken the role of South Texas Senior Chairman [3]. - Additional members of American Bank management will retain leadership roles in the combined organization, and Raffaele along with Patt Hawn Wallace have joined the Board of Directors of Prosperity Bank [3]. Group 3: Company Overview - As of September 30, 2025, Prosperity Bancshares, Inc. is a $38.330 billion regional financial holding company providing a range of banking services across Texas and Oklahoma [5]. - Prosperity operates 283 full-service banking locations across various regions, including 62 in the Houston area and 61 in the Dallas/Fort Worth area [6].