X0306 4 2015-03-17 0001018399 ENTERPRISE BANCORP INC /MA/ EBTC 0001183634 LERNER ARNOLD S C/O ENTERPRISE BANCORP 222 MERRIMACK STREET LOWELL MA 01852 1 Common Stock 2015-03-17 4 A 0 428 0 A 292389.2422 D Common Stock 218647.37 I By Wife Common Stock 13033 I Thru The Lerner Family Limited Partnership The reporting person is the managing member of the Lerner Family LLC which is the general partner of the Lerner Family Limited Partnership. The reporting person disclaims beneficial ownership of reported securities except to the extent of his pecuniary interest therein. /s/ George L. Duncan as attorney-in-fact for Arnold S. Lerner 2015-03-19