X0306 4 2017-11-28 0001018399 ENTERPRISE BANCORP INC /MA/ EBTC 0001701817 DUNN RYAN C C/O ENTERPRISE BANCORP, INC. 222 MERRIMACK STREET LOWELL MA 01852 1 EVP-Principal Subsidiary Common Stock 2017-11-28 4 S 0 700 35.75 D 5074.3293 D Common Stock 38.4453 I By Children Includes 24.6761 shares acquired through dividend reinvestment on 6/1/17 Includes 23.4798 shares acquired through dividend reinvestment on 9/1/17 Includes .1670 shares acquired through the dividend reinvestment plan on 6/1/17 Includes .1591 shares acquired through the dividend reinvestment plan on 9/1/17 /s/ John P. Clancy, attorney-in-fact for Ryan C. Dunn 2017-11-30