X0202 4 2007-09-21 0 0001018399 ENTERPRISE BANCORP INC /MA/ EBTC 0001282759 ANSIN KEN S C/O ENTERPRISE BANK 222 MERRIMACK STREET LOWELL MA 01852 1 0 0 0 Common Stock 2007-09-21 4 P 0 100 13.50 A 120127.4080 D Common Stock 1000 I By Trust for son G.Ansin Common Stock 1000 I By Trust for Son K. Ansin Includes 512.199456 shares acquired through dividend reinvestment on 3/1/07 Includes 533.040376 shares acquired through dividend reinvestment on 6/1/07 Includes 606.947518 shares acquired through dividend reinvestment on 9/4/07 /s/ Richard W. Main as attorney-in-fact for Kenneth S. Ansin 2007-09-24