Third Coast Bancshares, Inc. ("Third Coast") (NYSE & NYSE Texas: TCBX), the parent company of Third Coast Bank, and Great Plains Bancshares, Inc. ("Great Plains"), the parent company of Great Plains National Bank, today jointly announced the signing of a definitive merger agreement pursuant to which Third Coast will acquire Great Plains in an all-stock transaction valued at approximately $239.6 million based on Third Coast's closing stock price as of October 6, 2026. On a pro forma basis, the combined company is expected to have approximately $9 billion in assets following the completion of the transaction.

The strategic partnership creates an opportunity to combine two culturally aligned, relationship‑driven community banks, expand Third Coast's Dallas presence and establish Third Coast's entry into the Oklahoma market. Great Plains, headquartered in Oklahoma City, Oklahoma, has served its markets for more than 100 years and operates a 23-branch franchise across Oklahoma and Texas.

Under the terms of the merger agreement, Thunder Merger Sub, Inc., a wholly owned subsidiary of Third Coast, will merge into Great Plains, with Great Plains' shareholders receiving shares of Third Coast common stock in exchange for their shares of Great Plains' common stock. Following the merger, Great Plains will merge into Third Coast and Great Plains National Bank will merge into Third Coast Bank. Great Plains will continue operating under the Great Plains brand as Great Plains Bank, a division of Third Coast Bank. Third Coast will continue to trade on the NYSE and NYSE Texas under the symbol "TCBX."

Third Coast expects to issue 5,570,352 shares of its common stock, resulting in pro forma equity ownership of approximately 78% by Third Coast shareholders and 22% by Great Plains shareholders. Two Great Plains representatives will be appointed to the boards of directors of Third Coast and Third Coast Bank, and Mr. Russell, Great Plains' Chief Executive Officer, has agreed to continue serving in a leadership role following the closing.

The transaction has been unanimously approved by the board of directors of both companies and is expected to close in the first quarter of 2027, subject to customary regulatory approvals and other closing conditions. Closing is also subject to approval of Great Plains' shareholders of the merger agreement and the merger, as well as approval by Third Coast's shareholders of the issuance of Third Coast common stock pursuant to the merger agreement.