Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-K ý ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2019 OR ¨ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 001-33912 Enterprise Bancorp, Inc. (Exact name of registrant as specified in its charter) | --- | --- | |------------------------- ...

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2019 Commission File Number: 001-33912 Enterprise Bancorp, Inc. (Exact name of registrant as specified in its charter) Massachusetts 04-3308902 (State or other jurisdiction of (I.R.S. Employer Identification No.) incorporation or organization) 222 Merrimack Street, Lowell, Massa ...

Table of Contents Title of each class Trading Symbol(s) Name of each exchange on which registered Common Stock, $0.01 par value per share EBTC NASDAQ Stock Market UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2019 Commission File Number: 001-33912 Enterprise Bancorp, Inc. (Exact name of registrant as specified in its charter) Massachusetts 04-330 ...

Table of Contents Title of each class Trading Symbol(s) Name of each exchange on which registered Common Stock, $0.01 par value per share EBTC NASDAQ Global Market UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2019 Commission File Number: 001-33912 Enterprise Bancorp, Inc. (Exact name of registrant as specified in its charter) Massachusetts 04-3 ...

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-K ý ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2018 OR ¨ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 001-33912 Enterprise Bancorp, Inc. (Exact name of registrant as specified in its charter) Massachusetts 04-3308902 (State or other ...