X0306 4 2016-01-27 0001018399 ENTERPRISE BANCORP INC /MA/ EBTC 0001637601 Rayno Peter C/O ENTERPRISE BANCORP, INC. 222 MERRIMACK STREET LOWELL MA 01852 1 EVP - Principal Subsidiary Common Stock 2016-01-27 4 F 0 90 20.47 D 5335.2725 D Includes 3.2959 shares purchased through the Issuer's Employee Stock Purchase Plan on 3/23/15 Includes 3.2606 shares purchased through the Issuer's Employee Stock Purchase Plan on 4/2/15 Includes 1.3256 shares acquired through the Issuer's Employee Stock Purchase Plan on 6/5/15 Includes 1.3024 shares acquired through the Issuer's Employee Stock Purchase Plan on 9/8/15 Includes 1.1592 shares acquired through the Issuer's Employee Stock Purchase Plan on 12/7/15 /s/ George L. Duncan as attorney-in-fact for Peter J Rayno 2016-01-29