Third Coast Bancshares, Inc.

Contact: Ken Dennard / Natalie Hairston Dennard Lascar Investor Relations (713) 529-6600 TCBX@dennardlascar.com

FOR IMMEDIATE RELEASE Third Coast Bancshares, Inc. Reports 2026 Third Quarter Financial Results Solid 2026 Third Quarter Results While Advancing Long-Term Growth Strategy HOUSTON, October 21, 2026 - Third Coast Bancshares, Inc. (NYSE and NYSE Texas: TCBX) (the "Company," "Third Coast," "we," "us,"or"our"), the bank holding company for Third Coast Bank (the "Bank"), today reported its 2026 third quarter financial results. 2026 Third Quarter Financial and Operational Highlights • Return on average assets of 1.13% annualized for the third quarter of 2026 compared to 1.34% annualized for the second quarter of 2026 and 1.41% annualized for the third quarter of 2025. Return on average assets as adjusted (non-GAAP) (1) annualized for the third quarter of 2026 was 1.29%.

• Net interest margin of 3.70% for the third quarter of 2026 compared to 3.83% for the second quarter of 2026 and 4.10% for the third quarter of 2025.

• Net income for the third quarter of 2026 totaled $19.0 million, or $1.07 and $0.93 per basic and diluted share, respectively, compared to $22.0 million, or $1.25 and $1.08 per basic and diluted share, respectively, for the second quarter of 2026 and $18.1 million, or $1.22 and $1.03 per basic and diluted share, respectively, for the third quarter of 2025. Excluding $3.2 million of acquisition-related expenses in the third quarter of 2026, the net income as adjusted (non-GAAP) (1) for the third quarter of 2026 was $21.6 million, or $1.06 per diluted share as adjusted (non-GAAP) (1) .

• Efficiency ratio of 63.10% for the third quarter of 2026 compared to 56.51% for the second quarter of 2026 and 53.03% for the third quarter of 2025.

• Gross loans grew to $5.49 billion as of September 30, 2026, from $5.44 billion reported as of June 30, 2026.

• Book value per common share and tangible book value per common share (1) increased to $36.53 and $33.31, respectively, as of September 30, 2026, compared to $36.34 and $33.08, respectively, as of June 30, 2026 and $32.25 and $30.91, respectively, as of September 30, 2025.

• Noninterest bearing demand deposits increased $78.4 million to $721.2 million, or 12.2% of total deposits as of September 30, 2026, compared to 11.0% of total deposits as of June 30, 2026.

• On October 7, 2026, the Company announced a definitive merger agreement to acquire Great Plains Bancshares, Inc. ("Great Plains"), the parent company of Great Plains National Bank, in an all-stock transaction valued at approximately $239.6 million based on the Company's closing stock price as of October 6, 2026. The transaction is expected to close in the first quarter of 2027.

____________________________ (1) Non-GAAP financial measure. Please refer to the table titled "GAAP Reconciliation and Management's Explanation of Non-GAAP Financial Measures" at the end of this news release for a reconciliation of these non-GAAP financial measures.

"The third quarter reflects the underlying strength of our franchise and our continued focus on disciplined, relationship-driven growth," said Bart Caraway, Founder, Chairman, President, and Chief Executive Officer of Third Coast. "We saw healthy loan activity, continued progress in our funding base, stable credit performance, and another high in tangible book value per share. Additionally, our agreement to merge with Great Plains builds on the progress of our strategy and brings together two organizations with complementary strengths and shared values. We believe the transaction positions us to build an even stronger franchise capable of producing durable earnings and long-term stakeholder value." Operating Results Net Income and Earnings Per Common Share Net income totaled $19.0 million for the third quarter of 2026, compared to $22.0 million for the second quarter of 2026 and $18.1 million for the third quarter of 2025. Net income available to common shareholders totaled $17.8 million for the third quarter of 2026, compared to $20.8 million for the second quarter of 2026 and $16.9 million for the third quarter of 2025. The quarter-over-quarter decrease from the second quarter of 2026 was primarily due to the reduction of gain on sale of factored receivables from the second quarter of 2026 and an increase in merger and acquisition-related expenses during the third quarter of 2026. Dividends on our Series A Convertible Non-Cumulative Preferred Stock ("Series A Preferred Stock") totaled $1.2 million for each of the quarters ended September 30, 2026, June 30, 2026 and September 30, 2025. Basic and diluted earnings per common share were $1.07 per share and $0.93 per share, respectively, in the third quarter of 2026, compared to $1.25 per share and $1.08 per share, respectively, in the second quarter of 2026 and $1.22 per share and $1.03 per share, respectively, in the third quarter of 2025. In the third quarter of 2026, diluted earnings per common share as adjusted (non-GAAP) (1) was $1.06, compared to $0.98 diluted earnings per common share as adjusted (non-GAAP) (1) in the second quarter of 2026. Net Interest Margin and Net Interest Income The net interest margin for the third quarter of 2026 was 3.70%, compared to 3.83% for the second quarter of 2026 and 4.10% for the third quarter of 2025. The yield on loans for the third quarter of 2026 was 6.95%, compared to 7.06% for the second quarter of 2026 and 7.79% for the third quarter of 2025. The cost of interest-bearing deposits for the third quarter of 2026 was 3.49%, compared to 3.41% for the second quarter of 2026 and 3.98% for the third quarter of 2025. Net interest income totaled $59.5 million for the third quarter of 2026, a decrease of 1.2% from $60.3 million for the second quarter of 2026 and an increase of 17.1% from $50.8 million for the third quarter of 2025. Interest income totaled $106.7 million for the third quarter of 2026, an increase of 0.7% from $106.0 million for the second quarter of 2026 and an increase of 15.4% from $92.5 million for the third quarter of 2025. Interest expense was $47.2 million for the third quarter of 2026, an increase of $1.5 million, or 3.2%, from $45.7 million for the second quarter of 2026, and an increase of $5.5 million, or 13.3%, from $41.7 million for the third quarter of 2025. Noninterest Income and Noninterest Expense Noninterest income totaled $6.3 million for the third quarter of 2026, compared to $7.7 million for the second quarter of 2026 and $3.6 million for the third quarter of 2025. The quarter-over-quarter decrease from the second quarter of 2026 was primarily due to the reduction of gain on sale of factored receivables from the second quarter of 2026 partially offset by increased service charges and fees during the third quarter of 2026.

____________________________ (1) Non-GAAP financial measure. Please refer to the table titled "GAAP Reconciliation and Management's Explanation of Non-GAAP Financial Measures" at the end of this news release for a reconciliation of these non-GAAP financial measures. 2

Noninterest expense increased to $41.6 million for the third quarter of 2026, compared to $38.4 million for the second quarter of 2026 and $28.9 million for the third quarter of 2025. The quarter-over-quarter increase from the second quarter of 2026 was primarily due to merger and acquisition-related costs of $3.2 million. At September 30, 2026, the number of employees decreased to 499, compared to 504 at June 30, 2026. The efficiency ratio was 63.10% for the third quarter of 2026, compared to 56.51% for the second quarter of 2026 and 53.03% for the third quarter of 2025. Balance Sheet Highlights Loan Portfolio and Composition For the quarter ended September 30, 2026, gross loans increased to $5.49 billion, an increase of $57.1 million, or 1.1%, from $5.44 billion as of June 30, 2026, and an increase of $1.33 billion, or 31.9%, from $4.17 billion as of September 30, 2025. The Bank completed a securitization of $87.5 million of commercial real estate loans during the third quarter of 2026. Real estate loans accounted for the majority of the loan growth for the third quarter of 2026, with real estate loans increasing $67.1 million from the second quarter of 2026, partially offset by municipal and other loans decreasing $9.2 million from the second quarter of 2026. Asset Quality Nonperforming loans at September 30, 2026 were $29.0 million, compared to $27.1 million at June 30, 2026 and $21.7 million at September 30, 2025. The increase in nonperforming loans during the third quarter of 2026 was primarily due to $2.3 million in SBA loans placed on nonaccrual. As of September 30, 2026, the nonperforming loans to total loans ratio was 0.53%, compared to 0.50% as of June 30, 2026 and 0.52% as of September 30, 2025. The provision for credit losses recorded for the third quarter of 2026 was $540,000, and the allowance for credit losses of $54.4 million represented 0.99% of the $5.49 billion in gross loans outstanding as of September 30, 2026. The provision for credit losses recorded for the second quarter of 2026 was $2.1 million, and the allowance for credit losses of $53.6 million represented 0.99% of the $5.44 billion in gross loans outstanding as of June 30, 2026. The Company recorded net recoveries of $27,000 and $17,000 for the three months ended September 30, 2026 and September 30, 2025, respectively. Deposits and Composition Deposits totaled $5.92 billion as of September 30, 2026, an increase of 1.2% from $5.86 billion as of June 30, 2026, and an increase of 35.5% from $4.37 billion as of September 30, 2025. Noninterest-bearing demand deposits increased from $642.7 million as of June 30, 2026 to $721.2 million as of September 30, 2026 and represented 12.2% and 11.0% of total deposits as of September 30, 2026 and June 30, 2026, respectively. As of September 30, 2026, interest-bearing demand deposits decreased $141.1 million, or 3.3%, time deposits increased $126.1 million, or 14.6%, and savings accounts increased $5.9 million, or 21.1%, respectively, from June 30, 2026. The average cost of deposits was 3.09% for the third quarter of 2026, representing a 4-basis point increase from the second quarter of 2026 and a 47-basis point decrease from the third quarter of 2025. The quarter-over-quarter increase was primarily due to the increase in rates paid on interest-bearing demand deposits. Earnings Conference Call Third Coast has scheduled a conference call to discuss its 2026 third quarter results, which will be broadcast live over the Internet, on Thursday, October 22, 2026, at 11:00 a.m. Eastern Time / 10:00 a.m. Central Time. To participate in the call, dial 201-389-0869 and ask for the Third Coast Bancshares, Inc. call at least 10 minutes prior to the start time, or access it live over the Internet at https://ir.thirdcoast.bank/events-and-presentations/events/. For those who cannot listen to the live call, a replay will be available through October 29, 2026, and may be accessed by dialing

201-612-7415 and using passcode 13757906#. Also, an archive of the webcast will be available shortly after the call at https://ir.thirdcoast.bank/events-and-presentations/events/ for 90 days. About Third Coast Bancshares, Inc. Third Coast Bancshares, Inc. is a commercially focused, Texas-based bank holding company operating primarily in the Greater Houston, Dallas-Fort Worth, and Austin-San Antonio markets through its wholly owned subsidiary, Third Coast Bank. Founded in 2008 in Humble, Texas, Third Coast Bank conducts banking operations through 20 branches encompassing the four largest metropolitan areas in Texas. Please visit https://www.thirdcoast.bank for more information. Forward Looking Statements This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 that are subject to risks and uncertainties and are made pursuant to the safe harbor provisions of Section 27A of the Securities Act of 1933, as amended (the "Securities Act"), and Section 21E of the Securities Exchange Act of 1934, as amended. These forward-looking statements reflect our current views with respect to, among other things, future events and our financial performance. These statements are often, but not always, made through the use of words or phrases such as "may," "should," "could," "predict," "potential," "believe," "looking ahead," "will likely result," "expect," "continue," "will," "anticipate," "seek," "estimate," "intend," "plan," "projection," "would"and"outlook," or the negative version of those words or other comparable words or phrases of a future or forward-looking nature. These forward-looking statements are not historical facts, and are based on current expectations, estimates and projections about our industry, management's beliefs and certain assumptions made by management, many of which, by their nature, are inherently uncertain and beyond our control. Accordingly, we caution you that any such forward-looking statements are not guarantees of future performance and are subject to risks, assumptions and uncertainties that are difficult to predict. Although we believe that the expectations reflected in these forward-looking statements are reasonable as of the date made, actual results may prove to be materially different from the results expressed or implied by the forward-looking statements. There are or will be important factors that could cause our actual results to differ materially from those indicated in these forward-looking statements, including, but not limited to, the following: interest rate risk and fluctuations in interest rates; market conditions and economic trends generally and in the banking industry; our ability to maintain important deposit relationships; our ability to grow or maintain our deposit base; our ability to implement our expansion strategy; our ability to pay dividends on our Series A Preferred Stock; credit risk associated with our business; economic conditions affecting the real estate market; prepayment risks associated with commercial real estate loans; liquidity risks in the securitization market; operational risks related to the administration of securitized assets; changes in key management personnel; the occurrence of any event, change or other circumstance that could give rise to the right of one or both of the parties to terminate the definitive merger agreement providing for the acquisition of Great Plains by Third Coast; the outcome of any legal proceedings that may be instituted against Third Coast or Great Plains; the possibility that the transaction does not close when expected or at all because required regulatory, shareholder or other approvals and other conditions to closing are not received or satisfied on a timely basis or at all (and the risk that such approvals may result in the imposition of conditions that could adversely affect the combined company or the expected benefits of the transaction); the risk that the benefits from the transaction may not be fully realized or may take longer to realize than expected, including as a result of changes in, or problems arising from, general economic and market conditions, interest and exchange rates, monetary policy, laws and regulations and their enforcement, and the degree of competition in the geographic and business areas in which Third Coast and Great Plains operate; disruption to the parties' businesses as a result of the announcement and pendency of the transaction; the risk that the integration of each party's operations will be materially delayed or will be more costly or difficult than expected or that the parties are otherwise unable to successfully integrate each party's businesses into the other's businesses; the possibility that the transaction may be more expensive to complete than anticipated, including as a result of unexpected factors or events; reputational risk and potential adverse reactions of Third Coast's or Great Plains' customers, suppliers, employees or other business partners, including those resulting from the announcement or completion of the transaction; the dilution caused by Third Coast's issuance of additional shares of its common stock in connection with the transaction; a material adverse change in the financial condition of

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