Exhibit 99.1

FOR IMMEDIATE RELEASE

ATTENTION: FINANCIAL AND BUSINESS EDITORS

NBT BANCORP INC. ANNOUNCES 2012 DILUTED EARNINGS PER SHARE OF $1.62 AND

ORGANIC LOAN GROWTH OF 6.8%; DECLARES CASH DIVIDEND

NORWICH, NY (January 28, 2013) – NBT Bancorp Inc. (NBT) (NASDAQ: NBTB) reported today net income for the year ended December 31, 2012 was $54.6 million, down $3.3 million, or 5.8%, from the year ended December 31, 2011. Net income per diluted share for the year ended December 31, 2012 was $1.62, down from $1.71 per diluted share for the year ended December 31, 2011. Net interest margin (on a fully taxable equivalent or FTE basis) was 3.86% for the year ended December 31, 2012, down 23 basis points from 4.09% for the year ended December 31, 2011. Return on average assets and return on average equity were 0.93% and 9.72%, respectively, for the year ended December 31, 2012, compared with 1.06% and 10.73%, respectively, for the year ended December 31, 2011.

Net income for the three months ended December 31, 2012 was $13.1 million, down $0.6 million, or 4.4%, from the three months ended December 31, 2011. Net income per diluted share for the three months ended December 31, 2012 was $0.39 per share, down from $0.41 per diluted share for the three months ended December 31, 2011. FTE net interest margin was 3.83% for the three months ended December 31, 2012, down 15 basis points from 3.98% for the three months ended December 31, 2011. Annualized return on average assets and return on average equity were 0.86% and 9.01%, respectively, for the three months ended December 31, 2012, compared with 0.97% and 10.09%, respectively, for the three months ended December 31, 2011.

Selected highlights for 2012 include:

“Throughout 2012, we worked against a challenging economic and regulatory environment while maintaining our focus on banking fundamentals and enhancing the long-term value of our company,” said NBT President and CEO Martin Dietrich. “We are pleased with our results, especially our success in the areas of organic loan growth and integration of seven former Legacy Banks branches and our Hampshire First Bank acquisition. We expect to complete our acquisition of Alliance Financial Corporation and its 26-branch network in central New York in early 2013. This acquisition is another important step in further building our franchise in key markets where we identify strategic opportunities.”

Loan Quality and Provision for Loan Losses

The Company recorded a provision for loan losses of $20.3 million during the year ended December 31, 2012, compared with $20.7 million for the year ended December 31, 2011. Net charge-offs were $22.3 million for the year ended December 31, 2012, up from $20.6 million for the same period in 2011, due primarily to the charge-off of two large commercial loans during the fourth quarter of 2012. Net charge-offs to average loans for the year ended December 31, 2012 was 0.55%, compared to 0.56% for the year ended December 31, 2011.

The Company recorded a provision for loan losses of $6.9 million during the three months ended December 31, 2012, compared with $5.6 million for the three months ended December 31, 2011. Net charge-offs were $8.3 million for the three months ended December 31, 2012 and $5.6 million for the three months ended December 31, 2011.

Past due loans as a percentage of total loans was 0.71% at December 31, 2012, down from 0.89% at December 31, 2011. Nonperforming loans to total loans improved to 0.98% at December 31, 2012 as compared with 1.09% at December 31, 2011.

The allowance for loan losses totaled $69.3 million at December 31, 2012, compared to $71.3 million at December 31, 2011. The allowance for loan losses as a percentage of loans was 1.62% at December 31, 2012, compared to 1.66% at September 30, 2012, 1.70% at June 30, 2012, 1.87% at March 31, 2012, and 1.88% at December 31, 2011. The reduction of the allowance throughout the year was due primarily to the aforementioned improvement in key asset quality indicators, as well as improvement in certain economic indicators. In addition, the reduction in the second quarter of 2012 was due in part to acquired loans that were recorded at fair value at acquisition. As acquired loans do not have a related allowance recorded, the acquisition resulted in a decrease of 10 basis points in the allowance for loan losses as a percentage of total loans as of December 31, 2012.

Net Interest Income

Net interest income was up to $204.2 million for the year ended December 31, 2012, compared with $200.3 million for the year ended December 31, 2011. The Company’s FTE net interest margin was 3.86% for the year ended December 31, 2012, down from 4.09% for the year ended December 31, 2011. Average earning assets for the year ended December 31, 2012 was $5.4 billion, compared to $5.0 billion for the same period of 2011. This increase offset the decline in rates, resulting in a $3.9 million increase in net interest income for year ended December 31, 2012.

While the rate paid on interest bearing liabilities decreased 17 basis points, the yield on interest earning assets declined 37 basis points compared to the same period for 2011, resulting in margin compression for the year ended December 31, 2012. The yield on securities available for sale was 2.45% for the year ended December 31, 2012, compared with 2.97% for the year ended December 31, 2011. This decrease was due primarily to the reinvestment of cash flows from maturing securities and cash received from branch acquisitions in 2011 and the first quarter of 2012 into lower yielding securities in the current rate environment. The average balance of securities available for sale for the year ended December 31, 2012 was $1.2 billion, up approximately $54.8 million, or 4.9%, from the year ended December 31, 2011. This increase was due primarily to reinvestment of cash flows from held to maturity securities into available for sale securities, and investment of liquidity from branch acquisition activity and deposit growth. The yield on loans was 5.17% for the year ended December 31, 2012, compared with 5.58% for the year ended December 31, 2011. The average balance of loans for the year ended December 31, 2012 was $4.1 billion, up approximately $375.5 million ($124.3 million from acquisitions), or 10.2%, from the year ended December 31, 2011. The reduction in yields on earning assets was partially offset by a reduction in rates paid on interest bearing liabilities. The rate on time deposits was 1.45% for the year ended December 31, 2012, compared with 1.80% for the year ended December 31, 2011. The rate on money market deposit accounts was 0.18% for the year ended December 31, 2012, compared with 0.34% for the year ended December 31, 2011.

Net interest income was up to $52.5 million for the three months ended December 31, 2012, compared with $50.5 million for the three months ended December 31, 2011. The Company’s FTE net interest margin was 3.83% for the three months ended December 31, 2012, down from 3.98% for the three months ended December 31, 2011. The increase in average earning assets for the three months ended December 31, 2012 as compared to the same period of 2011 offset the decline in rates, resulting in the increase in net interest income over the same period last year.

While the rate paid on interest bearing liabilities decreased 15 basis points, the yield on interest earning assets declined 28 basis points, resulting in margin compression for the three months ended December 31, 2012, compared to the same period for 2011. The yield on securities available for sale was 2.27% for the three months ended December 31, 2012, as compared with 2.70% for the three months ended December 31, 2011. This decrease was due primarily to the reinvestment of cash flows from maturing securities and cash received from previous branch acquisitions into lower yielding securities in the current rate environment. The average balance of securities available for sale for the three months ended December 31, 2012 was $1.1 billion, down approximately $51.9 million, or 4.4%, from the three months ended December 31, 2011, as cash flows from maturing available for sale securities was used to support the aforementioned loan growth. The yield on loans was 5.05% for the three months ended December 31, 2012, compared with 5.45% for the three months ended December 31, 2011. The average balance of loans for the three months ended December 31, 2012 was $4.3 billion, up approximately $505.8 million, or 13.5%, from the three months ended December 31, 2011. The reduction in yields on earning assets was partially offset by a reduction in rates paid on interest bearing liabilities. The rate on time deposits was 1.31% for the three months ended December 31, 2012, compared with 1.72% for the three months ended December 31, 2011. The rate on money market deposit accounts was 0.14% for the three months ended December 31, 2012, compared with 0.24% for the three months ended December 31, 2011.

Noninterest Income

Noninterest income for the year ended December 31, 2012 was $87.3 million, up 8.7% or $7.0 million, compared with $80.3 million for the same period in 2011. Insurance and other financial services revenue increased approximately $1.5 million for the year ended December 31, 2012, compared to the year ended December 31, 2011. This increase was due primarily to the acquisition of an

insurance agency during the second quarter of 2011 as well as organic growth in commercial product lines. Retirement plan administration fees increased approximately $1.2 million for the year ended December 31, 2012, compared to the year ended December 31, 2011, due primarily to an increase in customer base. ATM and debit card fees increased approximately $0.7 million for the year ended December 31, 2012, compared to the year ended December 31, 2011, due primarily to an increase in card usage and customer base. Other noninterest income increased approximately $6.1 million for the year ended December 31, 2012 as compared to December 31, 2011. This increase was due in part to a $1.1 million payoff gain on a purchased commercial real estate loan. In addition, the Company recognized nonrecurring items totaling approximately $1.4 million during 2012 including a prepayment penalty fee related to a previously disclosed loss of a retirement plan client and flood related recoveries. Further, mortgage banking revenue increased approximately $2.6 million for the year ended December 31, 2012 as compared to the same period in 2011 as the Company sold certain residential mortgages as market conditions warranted. The Company sold approximately $64.6 million residential mortgages during 2012, as compared to approximately $17.5 million sales during 2011, while also experiencing more favorable gains during 2012. The Company also realized net securities gains of approximately $0.6 million during the year ended December 31, 2012, as compared to $0.2 million for the same period in 2011. These increases were partially offset by a decrease in service charges on deposit accounts of approximately $3.2 million, or 15.1%, for the year ended December 31, 2012, compared with the same period in 2011 primarily due to a decrease in overdraft fee income.

Noninterest income for the three months ended December 31, 2012 was $22.0 million, up 9.1% or $1.8 million, compared with $20.1 million for the same period in 2011. Retirement plan administration fees increased approximately $0.5 million for the three months ended December 31, 2012, compared to the three months ended December 31, 2011, due primarily to an increase in customer base. Insurance and other financial services revenue increased approximately $0.4 million for the three months ended December 31, 2012, compared to the three months ended December 31, 2011. This increase was due primarily to organic growth in commercial product lines. Other noninterest income increased approximately $1.5 million for the three months ended December 31, 2012 as compared to the three months ended December 31, 2011. This increase was due primarily to an increase in mortgage banking income of approximately $0.6 million, resulting from an increase in mortgage sales activity and more favorable gains during the three months ended December 31, 2012 as compared with the three months ended December 31, 2011. The Company also experienced an increase in loan fee income during the fourth quarter of 2012 which contributed to the increase in other noninterest income. These increases were partially offset by a decrease in service charges on deposit accounts of approximately $0.7 million, or 13.3%, for the three months ended December 31, 2012, compared with the same period in 2011 primarily due to the aforementioned decrease in overdraft fee income.

Noninterest Expense and Income Tax Expense

Noninterest expense for the year ended December 31, 2012 was $193.9 million, up $13.2 million or 7.3%, for the same period in 2011. Salaries and employee benefits increased $5.6 million, or 5.6%, for the year ended December 31, 2012, compared with the same period in 2011. This increase was due primarily to increases in full-time-equivalent employees from acquisitions, merit increases, and increased pension expense. Professional fees and outside services increased $1.5 million, or 17.3%, for the year ended December 31, 2012 as compared to 2011. Data processing, communications, and occupancy expenses increased approximately $2.2 million collectively, or 7.7%, for the year ended December 31, 2012 as compared to 2011, due primarily to increased activity from recent expansion into new markets. The Company incurred approximately $2.6 million in merger related expenses for the year ended December 31, 2012, as compared to $0.8 million for the same period in 2011. These increases were partially offset by a decrease in Federal Deposit Insurance Corporation (“FDIC”) expenses of approximately $0.4 million for the year ended December 31, 2012 as

compared to the year ended December 31, 2011. This decrease was due to the FDIC redefining the deposit insurance assessment base effective the second quarter of 2011. In addition, advertising expenses were down approximately $0.6 in 2012 as compared with 2011 due in large part to expense reduction initiatives. Income tax expense for the year ended December 31, 2012 was $22.8 million, up from $21.3 million for the same period in 2011. The effective tax rate was 29.5% for the year ended December 31, 2012, compared to 26.9% for the same period in 2011. The relatively low effective tax rate in 2011 was driven primarily by a reduction in tax expense as a result of the settlement of a New York State tax audit during the fourth quarter of 2011.

Noninterest expense for the three months ended December 31, 2012 was $48.6 million, up $1.2 million or 2.5%, for the same period in 2011. Salaries and employee benefits increased $1.4 million, or 5.4%, for the three months ended December 31, 2012, compared with the same period in 2011. This increase was due primarily to increases in full-time-equivalent employees from acquisitions, merit increases, and increased pension expense. Occupancy expenses for the three months ended December 31, 2012 increased $0.3 million, or 7.5%, over the same period in 2011 primarily due to aforementioned expansion. These increases were partially offset by a decrease in advertising expenses of approximately $0.6 million for the three months ended December 31, 2012 as compared to the same period in 2011, due primarily to expense reduction initiatives. In addition, other operating expenses decreased $0.4 million for the three months ended December 31, 2012 as compared to the same period in 2011, due to various cost cutting initiatives. Income tax expense for the three month period ended December 31, 2012 was $5.8 million, up from $3.9 million for the same period in 2011. The effective tax rate was 30.5% for the three months ended December 31, 2012, compared to 22.22% for the same period in 2011. The relatively low effective tax rate in 2011 was driven primarily by the aforementioned tax audit settlement.

Balance Sheet

Total assets were $6.0 billion at December 31, 2012, up $443.9 million or 7.9% from December 31, 2011. Loans were $4.3 billion at December 31, 2012, up $477.4 million from December 31, 2011. Total deposits were $4.8 billion at December 31, 2012, up $417.2 million from December 31, 2011. Stockholders’ equity was $582.3 million, representing a total equity-to-total assets ratio of 9.64% at December 31, 2012, compared with $538.1 million or a total equity-to-total assets ratio of 9.61% at December 31, 2011.

Stock Repurchase Program

Under previously disclosed stock repurchase plans, the Company purchased 769,568 shares of its common stock during the year ended December 31, 2012, for a total of $15.5 million at an average price of $20.13 per share. At December 31, 2012, there were 748,013 shares available for repurchase under a previously disclosed repurchase plan, which expires on December 31, 2013.

Dividend

The NBT Board of Directors declared a 2013 first-quarter cash dividend of $0.20 per share at a meeting held today. The dividend will be paid on March 15, 2013 to shareholders of record as of March 1, 2013.

Corporate Overview

NBT Bancorp Inc. is a financial holding company headquartered in Norwich, N.Y., with total assets of $6.0 billion at December 31, 2012. The company primarily operates through NBT Bank, N.A., a full-service community bank with three divisions,

and through two financial services companies. NBT Bank, N.A. has 135 locations, including 95 NBT Bank offices in upstate New York, northwestern Vermont and western Massachusetts, 35 Pennstar Bank offices in northeastern Pennsylvania, and 5 Hampshire First Bank offices in southern New Hampshire. EPIC Advisors, Inc., based in Rochester, N.Y., is a full-service 401(k) plan recordkeeping firm. Mang Insurance Agency, LLC, based in Norwich, N.Y., is a full-service insurance agency. More information about NBT and its divisions can be found on the Internet at: www.nbtbancorp.com, www.nbtbank.com, www.pennstarbank.com, www.hampshirefirst.com, www.epic1st.com and www.manginsurance.com.

Forward-Looking Statements

This news release contains forward-looking statements. These forward-looking statements involve risks and uncertainties and are based on the beliefs and assumptions of the management of NBT Bancorp and its subsidiaries and on the information available to management at the time that these statements were made. There are a number of factors, many of which are beyond NBT’s control, that could cause actual conditions, events or results to differ significantly from those described in the forward-looking statements. Factors that may cause actual results to differ materially from those contemplated by such forward-looking statements include, among others, the following possibilities: (1) competitive pressures among depository and other financial institutions may increase significantly; (2) revenues may be lower than expected; (3) changes in the interest rate environment may reduce interest margins; (4) general economic conditions, either nationally or regionally, may be less favorable than expected, resulting in, among other things, a deterioration in credit quality and/or a reduced demand for credit; (5) legislative or regulatory changes, including changes in accounting standards and tax laws, may adversely affect the businesses in which NBT is engaged; (6) competitors may have greater financial resources and develop products that enable such competitors to compete more successfully than NBT; (7) adverse changes may occur in the securities markets or with respect to inflation; (8) disruption of NBT’s business as a result of the announcement and pendency of the merger with Alliance Financial Corporation; (9) the risk that NBT’s and Alliance’s business may not be combined successfully, or such combination may take longer, cost more or otherwise be more difficult than expected; (10) operating costs, customer losses and business disruption following the merger, including adverse effects of relationships with employees, may be greater than expected; and (11) the risk that the anticipated benefits, costs savings and any other savings from the merger may not be fully realized or may take longer than expected to realize. Forward-looking statements speak only as of the date they are made. Except as required by law, NBT does not update forward-looking statements to reflect subsequent circumstances or events.

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NBT Bancorp Inc. and Subsidiaries

SELECTED FINANCIAL HIGHLIGHTS

(unaudited)

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