13. STOCK-BASED COMPENSATION

Stock-based compensation plan overview

The Company maintains three equity incentive plans: the 2018 Equity Incentive Plan (“2018 Plan”), the 2019 Employee, Director and Consultant Equity Incentive Plan (“2019 Plan”) and the 2020 Employee, Director, and Consultant Equity Incentive Plan (“2020 Plan” and collectively, “Incentive Plans”). The 2020 Plan serves as the successor to the 2019 Plan and 2018 Plan and provides for the issuance of incentive stock options ("ISOs"), nonqualified stock options, stock grants and stock-based awards to employees, directors, and consultants of the Company. No further awards will be issued under the 2018 Plan and 2019 Plan. As of  March 31, 2026, a total of 310,883 shares were available for grant under the 2020 Plan.

The Incentive Plans are administered by the Company's board of directors. Notwithstanding the foregoing, the board of directors may delegate concurrent responsibility for administering each plan, including with respect to designated classes of persons eligible to receive an award under each plan, to a committee or committees (which term shall include subcommittees) consisting of one or more members of the board of directors (collectively, the “Plan Administrator”), subject to such limitations as the board of directors deem appropriate.

In November 2020, the board of directors and stockholders approved the 2020 Plan and reserved an aggregate of 228,405 shares of common stock for issuance under the 2020 Plan. Pursuant to the 2020 Plan, the number of shares available for issuance under the 2020 Plan may be increased on January 1 of each year, beginning on January 1, 2021, and ending on January 2, 2030, in an amount equal to the lesser of (i) 4% of the outstanding shares of the Company’s common stock on such date or (ii) such number of shares determined by the Plan Administrator.

The 2020 Plan provides for the grant of ISOs, nonqualified stock options, stock grants, and stock-based awards that are based in whole or in part by reference to the Company’s common stock.

The tax benefits recognized in the condensed consolidated statements of operations for stock-based compensation arrangements for the three months ended March 31, 2026 and 2025, were not material to the financial statements.

Restricted Stock Unit Activity

RSUs granted to certain executives, employees and members of the board of directors expire 10 years after the grant date. The awards generally have a time-based vesting requirement (based on continuous employment). Upon vesting, the RSUs convert into shares of the Company's common stock. The stock-based compensation expense related to service-based awards is recorded over the requisite service period. During the three months ended March 31, 2026, the Company did not grant any RSU awards.

The following table summarizes the activity related to the Company's RSUs for the three months ended March 31, 2026. For purposes of this table, vested RSUs represent the shares for which the service condition had been fulfilled during the three months ended March 31, 2026:

As of  March 31, 2026, total unamortized stock-based compensation cost related to unvested RSUs was $277 and the weighted-average period over which the compensation is expected to be recognized is less than one year. For the three months ended March 31, 2026, the Company recognized $167 of total stock-based compensation expense for RSUs. As of  March 31, 2026, there were 77,460 RSUs which had vested, but were not yet issued due to the recipients' elections. For the three months ended March 31, 2026, the Company settled 79,249 previously deferred RSUs.

Performance Stock Unit Activity

During the three months ended March 31, 2026, the Company did not grant, vest, or transact in any PSUs. PSUs were granted in 2024, which vested in the second quarter of 2025, less forfeitures due to employee terminations and performance conditions that were not satisfied. There were no PSUs outstanding as of  March 31, 2026 or  December 31, 2025.

Stock Options

There were no stock options granted or exercised during the three months ended March 31, 2026. The following table summarizes the stock option activity for the three months ended March 31, 2026:

As of each  March 31, 2026 and  December 31, 2025, there were no unvested stock awards, and no compensation cost related to options not yet recognized. To the extent there are unvested stock option awards, the vesting of stock options is subject to certain change in control provisions as provided in the incentive plan agreements and stock options may be exercised up to 10 years from the date of issuance.