Employee Benefit Plans	3 Months Ended
Mar. 31, 2026
Postemployment Benefits [Abstract]
Employee Benefit Plans	13. Employee Benefit Plans In 2009, the Company adopted the Third Coast Bank, SSB 401(k) Plan covering substantially all employees. Employees may elect to defer a percentage of their compensation subject to certain limits based on federal tax laws. The Company may make a discretionary match of employees’ contributions based on a percentage of salary contributed by participants. Effective July 1, 2022, the Company amended the Third Coast Bank, SSB 401(k) Plan and merged that plan into the Third Coast Bank, SSB Employee Stock Ownership Plan (the “Merged Plan”). In connection with this amendment and plan merger, on July 1, 2022, the Company registered an aggregate of 400,000 shares of the Company's common stock, par value $1.00 per share, for issuance to the Merged Plan in connection with elections by participants to allocate a portion of their plan account balances (up to the limits prescribed under the Merged Plan) to the Company stock fund investment option. The number of shares held by the Third Coast Bank, SSB Employee Stock Ownership Plan immediately prior to the plan merger was 149,461 shares. Under the Merged Plan, discretionary contributions made by the Company will be invested at the direction of the plan participant, in accordance with participant plan elections. For the three months ended March 31, 2026 and 2025, Company contributions to the Merged Plan were approximately $548,000 and $407,000, respectively. Administrative expense related to the Merged Plan for the same three month periods totaled approximately $27,000 and $20,000, respectively. The costs are included in salaries and employee benefits in the accompanying consolidated statements of income. Phantom Stock Appreciation Plan On May 3, 2023, the Board of Directors approved the Third Coast Bancshares, Inc. Phantom Stock Appreciation Plan (the “Phantom Stock Plan”). Under the Phantom Stock Plan, participants are granted phantom stock units (“PSUs”) which vest ratably over a three-year period. The PSU confers to the participant the benefits of owning stock without the actual ownership or transfer of shares. Each stock unit entitles the participant to receive, upon vesting of each PSU, an amount equal to the sum of (a) the opening value and (b) the bonus amounts applicable to each PSU, as calculated pursuant to the terms of the Phantom Stock Plan and the Award Agreement. Settlement is payable to participants within 30 days of the vesting date. The Phantom Stock Plan is an unfunded plan whereby benefits are paid by the Company from its general assets, and participants have the rights of a general, unsecured creditor against the Company for any payments due hereunder. If a participant ceases, for any reason other than death or disability, to be a service provider, then the participant forfeits all rights to his or her outstanding PSUs. If the participant ceases to be a service provider due to the participant’s death or disability, then all unvested PSUs become fully vested on the date the participant ceases to be a service provider. For the three months ended March 31, 2026 and 2025, the Company had expensed $239,000 and $195,000, respectively, in deferred compensation related to the Phantom Stock Plan. The costs are included in salaries and employee benefits in the accompanying consolidated statements of income.

Employee Benefit Plans

3 Months Ended

Mar. 31, 2026

13.

Employee Benefit Plans

In 2009, the Company adopted the Third Coast Bank, SSB 401(k) Plan covering substantially all employees. Employees may elect to defer a percentage of their compensation subject to certain limits based on federal tax laws. The Company may make a discretionary match of employees’ contributions based on a percentage of salary contributed by participants.

Effective July 1, 2022, the Company amended the Third Coast Bank, SSB 401(k) Plan and merged that plan into the Third Coast Bank, SSB Employee Stock Ownership Plan (the “Merged Plan”). In connection with this amendment and plan merger, on July 1, 2022, the Company registered an aggregate of 400,000 shares of the Company's common stock, par value $1.00 per share, for issuance to the Merged Plan in connection with elections by participants to allocate a portion of their plan account balances (up to the limits prescribed under the Merged Plan) to the Company stock fund investment option. The number of shares held by the Third Coast Bank, SSB Employee Stock Ownership Plan immediately prior to the plan merger was 149,461 shares. Under the Merged Plan, discretionary contributions made by the Company will be invested at the direction of the plan participant, in accordance with participant plan elections.

For the three months ended March 31, 2026 and 2025, Company contributions to the Merged Plan were approximately $548,000 and $407,000, respectively. Administrative expense related to the Merged Plan for the same three month periods totaled approximately $27,000 and $20,000, respectively. The costs are included in salaries and employee benefits in the accompanying consolidated statements of income.

Phantom Stock Appreciation Plan

On May 3, 2023, the Board of Directors approved the Third Coast Bancshares, Inc. Phantom Stock Appreciation Plan (the “Phantom Stock Plan”). Under the Phantom Stock Plan, participants are granted phantom stock units (“PSUs”) which vest ratably over a three-year period. The PSU confers to the participant the benefits of owning stock without the actual ownership or transfer of shares. Each stock unit entitles the participant to receive, upon vesting of each PSU, an amount equal to the sum of (a) the opening value and (b) the bonus amounts applicable to each PSU, as calculated pursuant to the terms of the Phantom Stock Plan and the Award Agreement. Settlement is payable to participants within 30 days of the vesting date.

The Phantom Stock Plan is an unfunded plan whereby benefits are paid by the Company from its general assets, and participants have the rights of a general, unsecured creditor against the Company for any payments due hereunder. If a participant ceases, for any reason other than death or disability, to be a service provider, then the participant forfeits all rights to his or her outstanding PSUs. If the participant ceases to be a service provider due to the participant’s death or disability, then all unvested PSUs become fully vested on the date the participant ceases to be a service provider.

For the three months ended March 31, 2026 and 2025, the Company had expensed $239,000 and $195,000, respectively, in deferred compensation related to the Phantom Stock Plan. The costs are included in salaries and employee benefits in the accompanying consolidated statements of income.