X0206 3 2017-03-22 0 0001018399 ENTERPRISE BANCORP INC /MA/ EBTC 0001701784 GABRIEL JAMIE L C/O ENTERPRISE BANCORP, INC. 222 MERRIMACK STREET LOWELL MA 01852 1 EVP- Principal Subsidiary Common Stock 8890.3402 D Option (Right to Buy) 16.43 2023-03-18 Common Stock 650 D Option (Right to Buy) 20.29 2024-03-17 Common Stock 762 D Option (Right to Buy) 21.03 2025-03-16 Common Stock 807 D Option (Right to Buy) 21.86 2026-03-14 Common Stock 793 D Option (Right to Buy) 30.46 2027-03-20 Common Stock 364 D Options vest 50% on the second anniversary of the grant date and 50% on the fourth anniversary of the grant date. The first installment vested on March 19, 2015. Options are fully vested. Options vest 50% on the second anniversary of the grant date and 50% on the fourth anniversary of the grant date. The first installment vested on March 18, 2016. Options vest 50% on the second anniversary of the grant date and 50% on the fourth anniversary of the grant date. The first installment vested on March 17, 2017. Options vest 50% on the second anniversary date of the grant and 50% on the fourth anniversary date of the grant. The first installment vested on March 15, 2018. Options vest 50% on the second anniversary date of the grant and 50% on the fourth anniversary date of the grant. The first installment vests on March 21, 2019. /s/ John P. Clancy, attorney-in-fact for Jamie Gabriel 2017-03-29