2022 ANNUAL REPORT to our shareholders Fellow Shareholders, In a year underscored by volatile interest rate movements, unfavorable equity and fixed income market returns, we are pleased that our positive operating results drove total shareholder return of over 15% in 2022. Our achievement of 10 consecutive years of annual dividend increases was also a significant milestone that demonstrates our continued commitment to providing consistent and favorable long-term returns for our shareholders. Superior Operating Results. Under our traditional bank business model, our talented team achieved superior 2022 operating results that included net income of $152 million and earnings per diluted share of $3.52. Our full-year return on average tangible common equity was 16.9%, and our return on average assets was 1.29%. These results were defined by strong loan growth in connection with our strategy to expand the balance sheet, build scale, and generate positive operating leverage. Over 15% In 2022, net interest income increased 13% as our earning assets were well-positioned to take advantage of rising interest rates. TOTAL SHAREHOLDER Loans grew to $8.15 billion in 2022, up RETURN IN 2022 nearly 9% from the prior year. Credit quality remained strong, and nonperforming loans were down 36% year over year. Non-interest income generation makes up over a quarter of our revenue mix and continues to be a strength of our organization. In 2022, the revenue produced by our Retirement Plan Administration business increased 14% year over year, and total revenues for our Wealth and Insurance businesses grew to $48 million. 10 CONSECUTIVE YEARS ANNUAL DIVIDEND INCREASES Opportunities for Strategic Growth. Our financial accomplishments are the result of our team’s focus on key themes and strategies. The most important element of our future success lies in our efficient pursuit of organic growth across our lines of business and across our footprint. From time to time, we supplement that growth with strategic acquisitions. In 2022, we grew our Retirement Plan Administration and Insurance businesses in this way. In December, we were very pleased to announce a definitive agreement with Salisbury Bancorp, Inc. of Lakeville, CT to merge Salisbury Bank with and into NBT Bank. Our teams have been working to plan a seamless transition for Salisbury customers. We anticipate that, pending regulatory and Salisbury shareholder approval, the merger will close in the second quarter of 2023. We look forward to coming together with this high-quality, like-minded community bank and expanding our We have diverse and granular loan and deposit portfolios. footprint into northwest Connecticut, southwest Massachusetts Our 2022 lending highlights included new commercial loan and New York’s Hudson Valley. production of over $1 billion for the second consecutive year, a 9% increase in business banking loan originations, and over $1.4 billion in home, personal, auto, and residential solar loan production. On the funding side, we continued to successfully add net new accounts in 2022. company profile • NBT Bancorp Inc. is a financial holding company incorporated in 1986 in the state of Delaware. • The Company primarily operates through NBT Bank, N.A. and two financial services companies. • NBT Bank, N.A. offers personal banking, commercial banking and wealth management services through online and mobile channels and 140 locations in New York, Pennsylvania, Vermont, Massachusetts, New Hampshire, Maine and Connecticut. • EPIC Retirement Plan Services is a national benefits administration firm based in Rochester, NY. Significant new opportunities for long-term organic growth also emerged in 2022 with news of transformational chip fabrication investments in upstate New York. This includes the recent announcement of a $100 billion investment in Onondaga County by Micron Technology Inc. over the next 20 years and IBM’s planned investment of $20 billion in the Hudson Valley over the next decade. NBT is uniquely positioned to support this regional growth. Our branch network is ideally situated along the Chip Corridor with coverage from greater Syracuse to the Mohawk Valley Well Positioned TO SUPPORT GROWTH ALONG NY CHIP CORRIDOR and Capital District that will extend to the Hudson Valley through our planned Salisbury acquisition. Our leaders are connected to key economic and workforce development initiatives, and we are ready to assist our customers and communities in being a part of this historic growth opportunity. Our Digital Mindset. We continue to operate with a customer- first digital mindset and constantly upgrade the mobile and online services we provide to customers, who have embraced • NBT Insurance Agency, llc is a full-service insurance them with a 94% increase in consumer digital adoption over agency based in Norwich, NY. the last three years. NBT BANCORP INC. financial highlights (In thousands, except per share data) Our technology roadmap guides the ongoing enhancement FOR THE YEAR 2022 2021 of the customer and employee experience at NBT. Last year, our team continued to optimize new digital platforms for commercial lending, small business lending, consumer lending and financing through auto dealers. We also invested in technology to streamline and enhance the employee experience with new platforms for human capital management and accounting and finance. PERFORMANCE Net income . . . . . . . . . . . . . . . . . . . . . . . . . . . . $151,995 $154,885 Return on average assets . . . . . . . . . . . . . . . Return on average tangible equity . . . . . . Net interest margin . . . . . . . . . . . . . . . . . . . . . 1.29% 16.89% 3.34% 1.33% 16.92% 3.03% PER COMMON SHARE DATA Impacting Our Communities. As we have made great progress in moving our business forward, our team is also having a Diluted earnings . . . . . . . . . . . . . . . . . . . . . . . . Cash dividends . . . . . . . . . . . . . . . . . . . . . . . . . $3.52 $1.16 $3.54 $1.10 significant impact on the communities we serve. In addition to contributing $2 million to community organizations and logging thousands of employee volunteer hours, NBT helped make quality banking resources more accessible by opening more than 3,500 NBT iSelect Accounts across our footprint in 2022. This account is certified by the Cities for Financial Empowerment Fund as meeting the Bank On National Account Standards, and it assists accountholders in establishing a stable financial foundation. We also launched the NBT CEI-Boulos Impact Fund— a $10 million real estate equity investment fund with NBT Bank as the sole investor. This fund is designed to support individuals Dividend yield . . . . . . . . . . . . . . . . . . . . . . . . . . 2.67% 2.86% Tangible book value per share . . . . . . . . . . $20.65 $22.26 AT DECEMBER 31 BALANCE SHEET DATA Total assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . $11,739,296 $12,012,111 Total loans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $8,150,147 $7,498,459 Allowance for loan losses . . . . . . . . . . . . . . . $100,800 $92,000 Deposits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $9,495,933 $10,234,469 Total shareholders’ equity . . . . . . . . . . . . . . . $1,173,554 $1,250,453 ASSET QUALITY and communities with low and moderate incomes through Net charge-offs to average loans . . . . . . . . investments in high-impact, community-supported, commercial Nonperforming loans to total loans . . . . . . real estate projects located within the bank’s Community Nonperforming assets to total assets . . . . Reinvestment Act assessment areas in New York State. Allowance for loan losses to total loans . . The Power of Our People. NBT’s success is truly powered by our people. We have a dedicated team devoted to the ongoing pursuit of the strategies that have made us successful. We appreciate the guidance offered by our Board of Directors and extend best wishes to Joseph A. Santangelo, who will retire in May with 22 years of service. His commitment to our company and faithfulness to our community banking values have never wavered. We remain a strong, stable and well-capitalized company with various and long-established sources of liquidity. We could not be more optimistic about the future and the opportunities before us to grow our business and serve our customers and communities. Thank you for your support and confidence in NBT. Sincerely, John H. Watt, Jr. President and Chief Executive Officer Martin A. Dietrich Chairman of the Board 0.11% 0.26% 0.18% 1.24% 12.12% 13.19% 15.38% 0.13% 0.44% 0.27% 1.23% 12.25% 13.43% 15.73% CAPITAL Common equity tier 1 capital ratio . . . . . . . Tier 1 capital ratio . . . . . . . . . . . . . . . . . . . . . . . Total risk-based capital ratio . . . . . . . . . . . . Closing stock price . . . . . . . . . . . . . . . . . . . . . $43.42 $38.52 Market capitalization . . . . . . . . . . . . . . . . . . . $1,860,887 $1,662,832 2023 annual meeting Tuesday, May 16, 2023 | 10:00 a.m. ET www.virtualshareholdermeeting.com/NBTB2023 Forward-Looking Statements This letter contains statements that constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 and are subject to a number of risks and uncertainties. Such statements are not guarantees of future performance and actual results may differ materially from any forward-looking statements contained in this letter. For a discussion of the factors that might cause such differences, please refer to our filings with the Securities and Exchange Commission. 2022 ANNUAL REPORT leadership Executive Management Team John H. Watt, Jr. President and CEO Sarah A. Halliday Executive Vice President and President of Commercial Banking Shauna M. Hyle Executive Vice President, Consumer Lending Scott A. Kingsley Executive Vice President and Chief Financial Officer Ruth H. Mahoney Executive Vice President, President of Wealth Management and Regional President for the Capital District and North Country EPIC Retirement Plan Services Manuel Marques, cpc, qpa, qka, qpfc, aif® President NBT Insurance Agency, llc Tucker H. Lounsbury, cic President M. Randolph Sparks Executive Vice President, General Counsel, Chief Ethics Officer and Corporate Secretary Joseph R. Stagliano Executive Vice President, President of Retail Community Banking and Chief Information Officer Amy Wiles Executive Vice President, Chief Credit Officer and Chief Risk Officer Regional Presidents Ruth H. Mahoney Capital District and North Country David A. Kavney Central New York and Mohawk Valley Jeffrey D. Lake Greater Binghamton Stephen P. Lubelczyk New England Andreas A. Kapetanopoulos Connecticut Kimberly J. Twitchell Maine Justin L. Jennings New Hampshire Daniel P. Werme Vermont and Massachusetts Board of Directors Martin A. Dietrich Chairman of the Board John H. Watt, Jr. President and CEO Johanna R. Ames J. David Brown Timothy E. Delaney James H. Douglas Heidi M. Hoeller Andrew S. Kowalczyk lll, Esq. V. Daniel Robinson ll Matthew J. Salanger Joseph A. Santangelo Lowell A. Seifter, Esq. Jack H. Webb NBT Bank Honorary Directors Richard Chojnowski Patricia T. Civil Daryl R. Forsythe Paul D. Horger, Esq. Janet H. Ingraham John C. Mitchell Van Ness D. Robinson Paul M. Solomon Paul O. Stillman Robert A. Wadsworth Additional information regarding our Executive Management Team and Board of Directors can be found in the proxy statement for our 2023 Annual Meeting of Stockholders. Operating Committee The following NBT leaders serve on the Operating Committee with the Executive Management Team and Regional Presidents. Annette L. Burns, SVP and Chief Accounting Officer Leonard P. Chinski, SVP and Chief Audit Officer Matthew K. Colgan, SVP and Regional Commercial Banking Manager, Pennsylvania Jeffrey S. Delepine II, SVP and Senior Director of Enterprise Risk Management Kurt T. Edwards, SVP and Chief Consumer Credit Officer Kenneth J. Entenmann, cfa®, SVP, Chief Investment Officer and Chief Economist Dawn D. Gillette, SVP and Head of FinTech Partners and Specialty Lending Amy S. Hurta, SVP and Senior Director of Operations David Krupski, SVP and Commercial Chief of Staff Tucker H. Lounsbury, cic, President, NBT Insurance Agency, llc Marc J. Monahan, SVP and Regional Executive, Glens Falls Joseph M. Ondesko, SVP and Corporate Treasurer Manuel S. Orta, SVP and Director of Business Development, Wealth Management Karen A. Sastri, VP and Chief Diversity Officer Cynthia A. Smaniotto, SVP and Chief Human Resources Officer Thomas M. Sutton, SVP and Director of Retail Banking Jennifer R. Telesky, SVP and Regional Commercial Banking Manager, Southern Tier Alfred V. Testa, SVP and Commercial Banking Executive, Capital Region Tara F. Trafton, SVP and Chief Commercial Credit Officer shareholder information Corporate Headquarters NBT Bancorp Inc. 52 South Broad Street Norwich, NY 13815 800.NBT.BANK Independent Auditors KPMG llP 515 Broadway Albany, NY 12207 Financial Reports and Releases Copies of the Company’s annual report to the Securities and Exchange Commission on Form 10-K, quarterly reports on Form 10-Q, and news releases may be obtained without charge by visiting our website at www.nbtbancorp.com or by writing to the attention of our Chief Financial Officer at the corporate headquarters address. Investor Relations Information regarding the Company, our dividend reinvestment and stock purchase plan, and direct deposit of dividends can be found on our website at www.nbtbancorp.com. Those seeking additional information may contact us by phone at 800.NBT.BANK (800.628.2265, Option 7) or by mail at the corporate headquarters address. Stock Transfer and Registrar Agent American Stock Transfer & Trust Company, LLC 6201 15th Avenue Brooklyn, NY 11219 800.NBT.BANK (800.628.2265, Option 7) www.astfinancial.com help@astfinancial.com www.nbtbancorp.com NBTBNasdaq Global Select Market