2013 Stock Option Plan

Upon shareholder approval in 2008, the Bank adopted the 2008 Stock Option Plan. In 2013, upon formation of Third Coast Bancshares, Inc., the Company adopted the 2013 Stock Option Plan (the “2013 Plan”). All outstanding options from the 2008 Stock Option Plan were grandfathered into the 2013 Plan. The 2013 Plan permits the grant of stock options for up to 500,000 shares of common stock from time to time during the term of the plan, subject to adjustment upon changes in capitalization. Under the 2013 Plan, the Bank may grant either incentive stock options or nonqualified stock options to eligible directors, executive officers, key employees and non-employee shareholders of the Bank. At March 31, 2026, there were no shares remaining available for grant for future awards as all outstanding options under the 2013 Plan were grandfathered into the 2019 Omnibus Incentive Plan (see 2019 Omnibus Incentive Plan). Awards outstanding under the 2013 Plan remain in full force and effect, according to their respective terms.

2019 Omnibus Incentive Plan

On May 29, 2019, the Company’s shareholders approved the Third Coast Bancshares, Inc. 2019 Omnibus Incentive Plan (the “2019 Plan”), which was previously approved by the Company’s board of directors. Under the 2019 Plan, the Company may issue stock options, stock appreciation rights, restricted stock, restricted stock units, stock bonuses, other stock-based awards, cash awards, and dividend equivalents. On May 20, 2021, the Company’s shareholders approved an amendment to the 2019 Plan such that the maximum number of shares reserved for issuance under the 2019 Plan was increased by an additional 500,000 shares. The maximum aggregate number of shares of common stock that may be issued under the 2019 Plan is equal to the sum of (i) 800,000 shares of common stock, (ii) the total number of shares remaining available for new awards under the 2013 Plan as of May 29, 2019, which was 152,750 shares of common stock, and (iii) any shares subject to outstanding stock options issued under the 2013 Plan to the extent that (A) any such

award is forfeited or otherwise terminates or is cancelled without the delivery of shares of common stock, or (B) shares of common stock are withheld from any such award to satisfy any tax or withholding obligation, in which case the shares of common stock covered by such forfeited, terminated or cancelled award or which are equal to the number of shares of common stock withheld, will become available for issuance under the 2019 Plan. At March 31, 2026, there were 36,627 shares remaining available for grant for future awards under the 2019 Plan.

2017 Non-Employee Director Stock Option Plan

In December 2017, the Company adopted the 2017 Non-Employee Director Stock Option Plan (the “Director Plan”). The Director Plan originally authorized the grant of stock options for up to 100,000 shares of common stock to non-employee directors of the Company pursuant to the terms of the Director Plan. During July 2018, the Company's board of directors approved the grant of stock options for 50,000 additional shares of common stock under the Director Plan, such that the Director Plan permitted the grant of stock options for up to 150,000 shares of common stock. On January 1, 2021, the Director Plan was amended and subsequently approved by the Company’s board of directors such that the aggregate number of shares of common stock to be issued pursuant to options shall not exceed 187,000 shares. Options are generally granted with an exercise price equal to the market price of the Company’s stock at the date of the grant. Option awards generally vest based on five years of continuous service and have 10-year contractual terms for non-controlling participants as defined by the Director Plan. Other grant terms can vary for controlling participants as defined by the Director Plan. At March 31, 2026, there were 166 shares remaining available for grant for future awards under the Director Plan.

Keystone Bancshares, Inc. 2021 Equity Incentive Plan

On February 1, 2026, the Company assumed the Keystone Bancshares, Inc. 2021 Equity Incentive Plan, as amended (the “Keystone Plan”) as part of the merger of the Company and Keystone. At merger date, 25,851 restricted stock units outstanding under the Keystone Plan were converted to 11,864 shares of the Company’s common stock, and 386,268 options outstanding under the Keystone Plan were converted to options to purchase 177,404 shares of the Company’s common stock at an exchange ratio of 0.45925, which was equal to the acquisition exchange rate for common shares. The options granted to employees under the Keystone Plan must be exercised within 5 years from the date of grant, and vesting schedules are determined on an individual basis. As of March 31, 2026, no shares were available for grant for future awards under the Keystone Plan.

Stock Options

The Company grants stock options under the 2019 Plan to certain directors, executive officers and other key employees of the Company. These stock options vest ratably over five years and have a 10-year contractual term. Options granted during the three months ended March 31, 2026 were granted with an exercise price ranging from $36.06 to $39.61. Options granted during the three months ended March 31, 2025 were granted with an exercise price of $35.40.

The fair value of each option award is estimated on the grant date using the Black-Scholes option-pricing model with the following assumptions used for the options granted in the three months ended March 31, 2026: risk-free interest rate ranging from 3.64% to 4.09%; dividend yield of 0.00%; estimated volatility ranging from 25.55% to 25.58%; and expected lives of options of 7.5 years. The following assumptions were used for options granted in the three months ended March 31, 2025: risk-free interest rate of 4.47%, dividend yield of 0.00%; estimated volatility of 24.25%; and expected lives of options of 7.5 years. Expected volatilities are based on historical volatilities of the Company’s common stock and similar peer group averages.

For the three months ended March 31, 2026 and 2025, the Company recognized share-based compensation expense of $124,000 and $132,000, respectively, associated with stock options. As of March 31, 2026, there was approximately $1.4 million of unrecognized compensation costs related to non-vested stock options that is expected to be recognized over the remaining period of 5.13 years. Forfeitures are recognized as they occur.

Shares issued in connection with stock compensation awards are issued from available authorized shares.

The total intrinsic value of outstanding in-the-money stock options and outstanding in-the-money exercisable stock options were $16.8 million and $14.1 million, respectively, at March 31, 2026. The total intrinsic value of outstanding in-the-money stock options and outstanding in-the-money exercisable stock options was $13.1 million and $9.2 million, respectively, at March 31, 2025.

The intrinsic value of stock options exercised during the three months ended March 31, 2026 and 2025 was approximately $507,000 and $642,000, respectively.

Warrants

In connection with the preferred stock private placement on September 30, 2022, the Company issued warrants to purchase an aggregate of 175,000 shares of the Company's common stock (or, at the election of the warrant holder in accordance with the terms of the warrant agreement, Series B Convertible Perpetual Preferred Stock, par value $1.00 per share (“Series B Preferred Stock”), or non-voting common stock, par value $1.00 per share (“Non-Voting Common Stock”), of the Company) (the “Preferred Warrants”) to certain investors. The Preferred Warrants are fully vested, and are exercisable over a seven-year period that expires on September 30, 2029. The weighted average remaining contractual life of the outstanding Preferred Warrants was 3.50 years as of March 31, 2026.

As of both March 31, 2026 and 2025, the Company had Preferred Warrants for 175,000 underlying shares outstanding and exercisable at a weighted average exercise price of $22.50.

Restricted Stock Awards

The Company grants restricted stock awards (“RSAs”) to certain directors, executive officers and employees of the Company. Restricted stock is common stock with certain restrictions that relate to trading and the possibility of forfeiture. Holders of restricted stock have full voting rights. Generally, the awards vest ratably over a two-to-four year period but vesting periods may vary. The RSAs have a 10-year contractual term.

Compensation expense for RSAs is recorded over the vesting period and is determined based on the number of restricted shares granted and the market price of our common stock at issue date. For the three months ended March 31, 2026 and 2025, the Company recognized share-based compensation expense associated with RSAs of approximately $301,000 and $200,000, respectively. As of March 31, 2026, there was approximately $4.6 million of unrecognized compensation costs related to non-vested RSAs that is expected to be recognized over a weighted average remaining period of 4.72 years.