v3.25.1
Stock-Based Compensation
3 Months Ended
Mar. 31, 2025
Share-Based Payment Arrangement [Abstract]  
Stock-Based Compensation Stock-Based Compensation
There have been no material changes to the Enterprise Bancorp, Inc. 2016 Stock Incentive Plan (the "2016 Plan") since December 31, 2024. As of March 31, 2025, 216,063 shares of Company common stock remained available for future grants under the 2016 Plan.

Total stock-based compensation expense was $549 thousand for the three months ended March 31, 2025, compared to $503 thousand for the three months ended March 31, 2024.

Stock Option Awards

The Company issued no stock options during the three months ended March 31, 2025 and March 31, 2024. As of March 31, 2025, there were 6,077 unvested outstanding stock options that are expected to vest over the remaining weighted average vesting period of 1.0 year.
The Company recognized stock-based compensation expense related to stock option awards of $23 thousand for the three months ended March 31, 2025, compared to $41 thousand for the three months ended March 31, 2024.

Restricted Stock Awards
 
Restricted stock awards are granted at the market price of the Company's common stock on the date of the grant. Employee restricted stock awards generally vest over four years in equal portions beginning on or about the first anniversary date of the restricted stock award or are performance-based restricted stock awards that vest upon the Company achieving certain predefined performance objectives. Non-employee director restricted stock awards generally vest over two years in equal portions beginning on or about the first anniversary date of the restricted stock award.

The table below provides a summary of restricted stock awards granted during the periods indicated:
Three months ended March 31,
Restricted Stock Awards (number of underlying shares)20252024
Four-year vesting 32,212 65,588 
Performance-based vesting 30,794 21,263 
Total restricted stock awards granted63,006 86,851 
Weighted average grant date fair value$39.60 $24.90 

Stock-based compensation expense recognized in association with stock awards, mainly restricted stock awards, amounted to $526 thousand for the three months ended March 31, 2025, compared to $402 thousand for the three months ended March 31, 2024.

Stock in Lieu of Directors' Fees
Prior to 2025, non-employee members of the Company's Board of Directors (the "Board") could opt to receive newly issued shares of the Company's common stock in lieu of cash compensation for attendance at meetings of the Board and committees of the Board. However, in connection with the proposed merger with Independent, the option to receive shares of Common Stock in lieu of cash fees was suspended for 2025. As a result, there was no stock-based compensation expense related to these directors' fees for the three months ended March 31, 2025, compared to $60 thousand for the three months ended March 31, 2024.