X0306 4 2021-12-31 0 0001068851 PROSPERITY BANCSHARES INC PB 0001185465 TIMANUS H E JR 4295 SAN FELIPE HOUSTON TX 77027 1 1 0 0 Chairman Common Stock 2021-12-31 4 A 0 1263 0.00 A 200937 D Common Stock 270260 I By Dooley Investments, LTD Common Stock 26229 I Through 401K Plan The Reporting Person and his spouse are general partners of Dooley Investments, LTD. The Reporting Person disclaims beneficial ownership of Prosperity Bancshares, Inc. common stock held by Dooley Investments, LTD except to the extent of his pecuniary interest. Includes 448 shares acquired through the Prosperity Bancshares, Inc. 401(k) plan since the last reporting. /s/ H.E. Timanus, Jr. 2022-01-04