Exhibit 99

Meridian Interstate Bancorp, Inc. Reports Net Income for the Fourth Quarter

and Year Ended December 31, 2011

Contact: Richard J. Gavegnano, Chairman and Chief Executive Officer

(978) 977-2211

Boston, Massachusetts (January 24, 2012): Meridian Interstate Bancorp, Inc. (the “Company” or “Meridian”) (NASDAQ: EBSB), the holding company for East Boston Savings Bank (the “Bank”), which also operates under the name Mt. Washington Bank, a Division of East Boston Savings Bank (“Mt. Washington”), announced net income of $2.0 million, or $0.09 per diluted share, for the quarter ended December 31, 2011 compared to $4.3 million, or $0.20 per diluted share, for the quarter ended December 31, 2010. For the year ended December 31, 2011, net income was $12.0 million, or $0.55 per diluted share compared to $13.4 million, or $0.61 per diluted share, for the year ended December 31, 2010. The Company’s return on average assets was 0.40% for the quarter ended December 31, 2011 compared to 0.95% for the quarter ended December 31, 2010. For the year ended December 31, 2011, the Company’s return on average assets was 0.63% compared to 0.77% for the year ended December 31, 2010. The Company’s return on average equity was 3.58% for the quarter ended December 31, 2011 compared to 7.99% for the quarter ended December 31, 2010. For the year ended December 31, 2011, the Company’s return on average equity was 5.45% compared to 6.38% for the year ended December 31, 2010.

Richard J. Gavegnano, Chairman and Chief Executive Officer, said, “I am pleased to report net income of $2.0 million, or $0.09 per share, for the fourth quarter and $12.0 million, or $0.55 per share, for the full year of 2011. Our actions in 2011 to build market share and earnings potential have already yielded significant results. Expansion of our residential and commercial real estate lending capacity and our entry into commercial and industrial lending contributed to net loan growth of 14% for 2011. We also had net deposit growth of 10% for 2011, with the opening of two East Boston Savings Bank branches and two Mt. Washington branches during the year contributing 40% of that growth. In addition, it is gratifying to see the increase in our quarterly net interest margin from earlier quarters in the year. Looking forward, the scheduled opening in early February of our new East Boston Savings Bank branch in Cambridge will provide an additional opportunity for growth in market share in the coming year.”

Net interest income decreased $136,000, or 0.9%, to $14.8 million for the quarter ended December 31, 2011 from $15.0 million for the quarter ended December 31, 2010. The net interest rate spread and net interest margin were 3.06% and 3.23%, respectively, for the quarter ended December 31, 2011 compared to 3.34% and 3.52%, respectively, for the quarter ended December 31, 2010. For the year ended December 31, 2011, net interest income decreased $3.2 million, or 5.2%, to $57.8 million from $61.0 million for the year ended December 31, 2010. The net interest rate spread and net interest margin were 3.06% and 3.24%, respectively, for the year ended December 31, 2011 compared to 3.62% and 3.80%, respectively, for the year ended December 31, 2010. The decreases in net interest income were due primarily to declines in yields on loans and securities for the fourth quarter and year ended December 31, 2011 compared to the same periods in 2010.

The Company’s yield on loans declined 31 basis points to 5.38%, which was partially offset by an increase in the average balance of the loan portfolio of $45.5 million, or 3.8%, to $1.230 billion for the year ended December 31, 2011 compared to the year ended December 31, 2010. For the year ended December 31, 2011, the average balance of total deposits increased $174.8 million, or 12.8%, to $1.536 billion, which was partially offset by a decline in the cost of total deposits of 13 basis points to 1.15% compared to the year ended December 31, 2010. The Company’s yield on interest-earning assets declined 70 basis points to 4.41% for the year ended December 31, 2011 compared to 5.11% for the year ended December 31, 2010, while the cost of funds declined 14 basis points to 1.25% for the year ended December 31, 2011 compared to 1.39% for the year ended December 31, 2010.

The Company’s provision for loan losses was $1.3 million for the quarter ended December 31, 2011 compared to $936,000 for the quarter ended December 31, 2010. For the year ended December 31, 2011, the provision for loan losses was $3.7 million compared to $3.2 million for the year ended December 31, 2010. The increases in the

provision for loan losses were based primarily on management’s assessment of loan portfolio growth and composition changes, an ongoing evaluation of credit quality and current economic conditions. The allowance for loan losses was $13.1 million or 0.96% of total loans outstanding at December 31, 2011, compared to $10.2 million or 0.86% of total loans outstanding at December 31, 2010.

Non-performing loans increased to $53.7 million, or 3.96% of total loans outstanding at December 31, 2011, from $43.1 million, or 3.64% of total loans outstanding at December 31, 2010. Non-performing assets increased to $57.5 million, or 2.91% of total assets, at December 31, 2011, from $47.2 million, or 2.57% of total assets, at December 31, 2010. Non-performing assets at December 31, 2011 were comprised of $22.4 million of construction loans, $11.6 million of commercial real estate loans, $15.8 million of one-to four-family mortgage loans, $1.6 million of multi-family mortgage loans, $1.8 million of home equity loans, $508,000 of commercial business loans and foreclosed real estate of $3.9 million. Non-performing assets at December 31, 2011 included $19.7 million of assets acquired in the January 2010 Mt. Washington Co-operative Bank merger, comprised of $17.4 million of non-performing loans and $2.3 million of foreclosed real estate.

Non-interest income decreased $729,000, or 19.8%, to $3.0 million for the quarter ended December 31, 2011 from $3.7 million for the quarter ended December 31, 2010, primarily due to decreases of $797,000 in gain on sales of securities, net, and $193,000 in equity income from the Company’s Hampshire First Bank affiliate, partially offset by an increase of $307,000 in customer service fees. For the year ended December 31, 2011, non-interest income increased $3.7 million, or 31.3%, to $15.4 million from $11.7 million for the year ended December 31, 2010, primarily due to increases of $2.7 million in gain on sales of securities, net, $314,000 in gain on sales of loans, net, and $618,000 in equity income from Hampshire First Bank. As announced in November 2011, Hampshire First Bank, which is approximately 40% owned by the Company, entered into an Agreement and Plan of Merger with NBT Bancorp, Inc. and NBT Bank, N.A. The merger is currently expected to be completed early in the second quarter of 2012.

Non-interest expense increased $2.5 million, or 22.9%, to $13.6 million for the quarter ended December 31, 2011 from $11.1 million for the quarter ended December 31, 2010, primarily due to increases of $1.5 million in salaries and employee benefits, $196,000 in occupancy and equipment expenses, $269,000 in marketing and advertising, $195,000 in professional services, and $322,000 in other general and administrative expenses. For the year ended December 31, 2011, non-interest expense increased $2.2 million, or 4.5%, to $51.0 million from $48.8 million for the year ended December 31, 2010, primarily due to increases of $3.8 million in salaries and employee benefits, $883,000 in occupancy and equipment expenses, $482,000 in marketing and advertising, $242,000 in professional services, and $322,000 in other general and administrative expenses, partially offset by decreases of $357,000 in deposit insurance, $160,000 in foreclosed real estate costs, $291,000 in recurring data processing costs and a $2.7 million charge during the year ended December 31, 2010 related to termination of the contract with Mt. Washington Co-operative Bank’s data processing services provider. The increases in salaries and employee benefits, occupancy and equipment and other general and administrative expenses were primarily associated with the new branches opened this year and costs associated with the expansion of residential and commercial lending capacity. The Company’s efficiency ratio was 77.40% for the quarter ended December 31, 2011 compared to 64.92% for the quarter ended December 31, 2010, excluding a reduction in the charge to terminate Mt. Washington Co-operative Bank’s data processing contract. For the year ended December 31, 2011, the efficiency ratio was 74.16% compared to 65.00% for the year ended December 31, 2010, excluding the charge to terminate Mt. Washington Co-operative Bank’s data processing contract.

Mr. Gavegnano noted, “The increases in our non-interest expenses and the efficiency ratio during 2011 are a direct result of our investment in additional lending capacity and new retail branches to expand sources of deposit funding. These investments are increasing our market share and significantly enhancing our franchise and stockholder value.”

The Company recorded a provision for income taxes of $946,000 for the quarter ended December 31, 2011, reflecting an effective tax rate of 32.5%, compared to $2.3 million, or 35.3%, for the quarter ended December 31, 2010. For the year ended December 31, 2011, the provision for income taxes was $6.6 million, reflecting an effective tax rate of 35.5%, compared to $7.4 million, or 35.6%, for the year ended December 31, 2010. The changes in the income tax provision were primarily due to the changes in pre-tax income.

2

Total assets increased $138.6 million, or 7.5%, to $1.974 billion at December 31, 2011 from $1.836 billion at December 31, 2010. Net loans increased $167.7 million, or 14.3%, to $1.341 billion at December 31, 2011 from $1.174 billion at December 31, 2010. Cash and cash equivalents increased $1.2 million, or 0.8%, to $156.7 million at December 31, 2011 from $155.5 million at December 31, 2010. Securities available for sale decreased $25.4 million, or 7.0%, to $335.2 million at December 31, 2011 from $360.6 million at December 31, 2010.

Total deposits increased $144.8 million, or 9.9%, to $1.604 billion at December 31, 2011 from $1.460 billion at December 31, 2010, reflecting net growth of $195.6 million in core deposits. The net deposit growth also reflects $57.4 million of new deposits in the four branches opened during 2011. Total borrowings decreased $17.2 million, or 11.6%, to $131.5 million at December 31, 2011 from $148.7 million at December 31, 2010, reflecting $21.8 million of reductions in Federal Home Loan Bank advances partially offset by a $4.5 million increase in short-term borrowings.

Mr. Gavegnano added, “Our focus on increasing core deposit relationships during 2011 resulted in growth in such non-term balances to $958.1 million, or 59.7% of total deposits at December 31, 2011.”

Total stockholders’ equity increased $4.3 million, or 2.0%, to $219.9 million at December 31, 2011, from $215.6 million at December 31, 2010. The increase for the year ended December 31, 2011 was due primarily to $12.0 million in net income, partially offset by a $5.2 million increase in treasury stock resulting from the Company’s repurchase of 392,663 shares and a $4.1 million decrease in accumulated other comprehensive income reflecting a decrease in the fair value of available for sale securities, net of tax. Stockholders’ equity to assets was 11.14% at December 31, 2011, compared to 11.74% at December 31, 2010. Book value per share increased to $9.93 at December 31, 2011 from $9.59 at December 31, 2010. Tangible book value per share increased to $9.31 at December 31, 2011 from $8.98 at December 31, 2010. Market price per share increased $0.66, or 5.6%, to $12.45 at December 31, 2011 from $11.79 at December 31, 2010. At December 31, 2011, the Company and the Bank continued to exceed all regulatory capital requirements.

As of December 31, 2011, the Company had repurchased 109,062 shares of its stock at an average price of $12.53 per share, or 12.1% of the 904,224 shares authorized for repurchase under the Company’s fourth repurchase program as adopted during 2011.

Mr. Gavegnano said, “Since late 2008, we have repurchased a total of 1,512,990 shares. We continue to consider additional stock repurchases, as well as various other opportunities to enhance stockholder value.”

Meridian Interstate Bancorp, Inc. is the holding company for East Boston Savings Bank. East Boston Savings Bank, a Massachusetts-chartered stock savings bank founded in 1848, operates 23 full service locations in the greater Boston metropolitan area including eight full service locations in its Mt. Washington Bank Division. We offer a variety of deposit and loan products to individuals and businesses located in our primary market, which consists of Essex, Middlesex and Suffolk Counties, Massachusetts. For additional information, visit www.ebsb.com.

Forward Looking Statements

Certain statements herein constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Such statements may be identified by words such as “believes,” “will,” “expects,” “project,” “may,” “could,” “developments,” “strategic,” “launching,” “opportunities,” “anticipates,” “estimates,” “intends,” “plans,” “targets” and similar expressions. These statements are based upon the current beliefs and expectations of Meridian Interstate Bancorp, Inc.’s management and are subject to significant risks and uncertainties. Actual results may differ materially from those set forth in the forward-looking statements as a result of numerous factors. Factors that could cause such differences to exist include, but are not limited to, general economic conditions, changes in interest rates, regulatory considerations, and competition and the risk factors described in the Company’s Annual Report on Form 10-K and Quarterly Reports on Form 10-Q as filed with the Securities and Exchange Commission. Should one or more of these risks materialize or should underlying beliefs or assumptions prove incorrect, Meridian Interstate Bancorp, Inc.’s actual results could differ materially from those discussed. Readers are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this release.

3

MERIDIAN INTERSTATE BANCORP, INC. AND SUBSIDIARIES

Consolidated Balance Sheets

(Unaudited)

4

MERIDIAN INTERSTATE BANCORP, INC. AND SUBSIDIARIES

Consolidated Statements of Income

(Unaudited)

5

MERIDIAN INTERSTATE BANCORP, INC. AND SUBSIDIARIES

Net Interest Income Analysis

(Unaudited)

6

MERIDIAN INTERSTATE BANCORP, INC. AND SUBSIDIARIES

Net Interest Income Analysis

(Unaudited)

7

MERIDIAN INTERSTATE BANCORP, INC. AND SUBSIDIARIES

Selected Financial Highlights

(Unaudited)

8