2020 A NNUAL R EPORT to our stockholders Fellow Stockholders, Today we are optimistic about the direction of the U.S. economy and the prospects for a strong recovery. NBT is well positioned to participate in that recovery for many reasons. Our Company grew stronger and even more resolved to succeed as we leveraged our culture and capabilities in 2020 to meet the relentless challenges of the COVID-19 pandemic and its wide-ranging impacts. Through uncertain times, our team maintained unwavering customer focus. When we were unable to meet customers in person, we continued to serve them through drive-up windows, calls, emails, and video conferencing. We used our lending, operational, and technical expertise to participate in the SBA’s Paycheck Protection Program (PPP), securing 3,000 loans for over $540 million that helped retain more than 61,000 jobs. Our industry played a crucial role in delivering this relief to provide businesses and their employees with a bridge to To understand our optimism, we must look back at a year a post-pandemic economy. These efforts continue as we where no aspect of life or business was untouched by adversity. aggressively assist current and new customers in the latest In early 2020, NBT was off to a strong start when the pandemic round of PPP funding. forced the world to alter course. We acted immediately and decisively to protect the health and safety of our employees, to offer relief and financial solutions to distressed customers, and to provide support to our communities. Amid this volatility, we posted solid 2020 financial results with reported net income of $104.4 million or $2.37 per diluted share. Our profitability measures were influenced by the adoption of the Current Expected Credit Loss (CECL) accounting standard, Our previous technology investments and comprehensive which drove the doubling of loan provision expense resulting pandemic response plan enabled us to quickly transition over from the pandemic’s perceived impact on the economy in the 90% of our non-branch staff to remote work. New health protocols and work processes were implemented to keep branch teams and other onsite workers safe. We offered additional health benefits and resources for dependent care, eldercare, and well-being to employees as we cross-trained and redeployed team members to the areas of greatest need. Through it all we are proud our efforts allowed us to maintain our dedicated workforce with no layoffs in 2020. As the pandemic drove adoption of digital products and services to new levels, our long-established technology roadmap positioned us to meet this need. Despite the unprecedented disruption, we were not deterred from executing on major planned enhancements in 2020, including the successful implementation of new mobile, online, and mortgage platforms. company profile • NBT Bancorp Inc. is a financial holding company incorporated in 1986 in the state of Delaware. markets where we do business. Our allowance for loan losses to total loans under the CECL methodology increased to 1.47%. We believe this level of allowance coverage and our low observed level of charge-offs in 2020 positions us well to absorb any potential trailing impacts of the pandemic on our loan portfolio. Loans were up over 5%, and deposits increased 20%. Both sides of the balance sheet were impacted by stimulus programs. In support of our clients and communities, we crossed the critical $10 billion asset threshold. This places us in the top 100 U.S. banks by asset size and is supported by years of preparation to become a “midsize” community bank. Our fee-based businesses delivered strong results. Total fee income was up 5% and represented nearly 32% of total revenue. This reflects contributions from wealth management, commercial banking, core banking fees, and the acquisition of Alliance Benefit Group in Illinois. We completed this acquisition on April 1, 2020 during the pandemic lockdown and successfully integrated new clients and team mates into our EPIC Retirement Plan Services business, increasing our total number of plan participants nationwide to over 265,000 and extending our • The Company primarily operates through NBT Bank, N.A. mission of “Helping America Retire.” and two financial services companies. • NBT Bank, N.A. offers personal banking, commercial banking, and wealth management services through online and mobile channels and 141 locations in New York, Pennsylvania, Vermont, Massachusetts, New Hampshire, and Maine. NBT Bank is currently entering Connecticut. Our strong balance sheet and capital position, disciplined approach to credit and risk management, technology investments, and diversified fee business provided NBT with flexibility to navigate these difficult times. In June 2020, we accessed the capital markets and raised $100 million in capital that we will deploy into growth opportunities in 2021 • EPIC Retirement Plan Services is a full-service 401(k) and beyond. recordkeeping firm based in Rochester, NY. We also maintained NBT’s long history of delivering consistent • NBT Insurance Agency, llc is a full-service insurance dividends with 2020 being our 163rd year of uninterrupted agency based in Norwich, NY. dividend payments. In addition, recognizing our responsibility NBT BANCORP INC. financial highlights (In thousands, except per share data) to return capital to stockholders, we repurchased shares in FOR THE YEAR 2020 2019 2020 and continued this activity in the first quarter of 2021. Recently, NBT’s Board of Directors took action to articulate our commitment to diversity, inclusion, and sustainability by resolving to define, measure, and highlight our long-established organizational values and corporate responsibility initiatives around the Environmental, Social, and Governance (ESG) pillars. PERFORMANCE Net income . . . . . . . . . . . . . . . . . . . . . . . . . . . . $104,388 $121,021 Return on average assets . . . . . . . . . . . . . . . Return on average tangible equity . . . . . . Net interest margin . . . . . . . . . . . . . . . . . . . . . This more formalized framework brings together the guiding PER COMMON SHARE DATA principles of community banking that are embedded in our Diluted earnings . . . . . . . . . . . . . . . . . . . . . . . . culture, and it provides us with an opportunity to better identify and enhance our impact as we move forward. Cash dividends . . . . . . . . . . . . . . . . . . . . . . . . . Dividend yield . . . . . . . . . . . . . . . . . . . . . . . . . . 0.99% 12.48% 3.31% $2.37 $1.08 3.36% 1.26% 15.85% 3.58% $2.74 $1.05 2.59% Closely tied to our Board’s commitment to ESG principals is our concern for racial equity and justice. It is our responsibility to provide leadership on these issues in the markets we serve. Tangible book value per share . . . . . . . . . . $20.52 $19.03 AT DECEMBER 31 As an employer, we have worked to enhance the diversity of our BALANCE SHEET DATA Board, our management team, and our employee population. This activity will increase awareness of the challenges our society faces and promote inclusion. Total assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . $10,932,906 $9,715,925 Total loans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $7,498,885 $7,136,098 Allowance for loan losses . . . . . . . . . . . . . . . $110,000 $72,965 As we reflect on 2020 and its unprecedented events, there Deposits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $9,081,692 $7,587,820 are many to whom we offer our thanks. First, we recognize Total stockholders’ equity . . . . . . . . . . . . . . . $1,187,618 $1,120,397 our Board members for their guidance and perspective. We were pleased to welcome Johanna R. Ames as a Director in September 2020. In addition, the Board has supported the nomination of J. David Brown to serve as a Director, and his name is on the slate of 14 Directors submitted to you for election at our 2021 Annual Meeting of Stockholders. At that meeting, our colleague Robert A. Wadsworth will retire from the Board after 16 years of distinguished service. Bob’s steady guidance through events like the financial crisis of 2008-2009, the COVID-19 pandemic, and his consistent focus on NBT’s long-term strategic goals have made him a key contributor. He will be missed, and we wish Bob and his family all the best. Finally, there aren’t enough words to express our appreciation to all of NBT’s employees. The courage and commitment our team drew upon to serve our customers and support our communities while facing tremendous personal challenges is humbling. We are grateful. We entered 2020 with optimism and momentum and are thankful we ended the year in the same way. We believe 2021 will be an important year for NBT. We appreciate your ongoing support as we move forward with our strategies to continue our disciplined growth and build on the long-term value of your investment. ASSET QUALITY Net charge-offs to average loans . . . . . . . . Nonperforming loans to total loans . . . . . . Nonperforming assets to total assets . . . . Allowance for loan losses to total loans . . CAPITAL Common equity tier 1 capital ratio . . . . . . . Tier 1 capital ratio . . . . . . . . . . . . . . . . . . . . . . . Total risk-based capital ratio . . . . . . . . . . . . 0.23% 0.64% 0.45% 1.47% 11.84% 13.09% 15.62% 0.36% 0.40% 0.31% 1.02% 11.29% 12.56% 13.52% Closing stock price . . . . . . . . . . . . . . . . . . . . . $32.10 $40.56 Market capitalization . . . . . . . . . . . . . . . . . . . $1,400,494 $1,776,391 2021 annual meeting Tuesday, May 25, 2021 | 10:00 a.m. www.virtualshareholdermeeting.com/NBTB2021 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 John H. Watt, Jr. President and Chief Executive Officer Martin A. Dietrich forward-looking statements contained in this letter. For a discussion Chairman of the Board of the factors that might cause such differences, please refer to our filings with the Securities and Exchange Commission. 2020 ANNUAL REPORT leadership Executive Management Team John H. Watt, Jr. President and Chief Executive Officer Timothy L. Brenner Executive Vice President and President of Wealth Management Sarah A. Halliday Executive Vice President and President of Commercial Banking Shauna M. Hyle Executive Vice President, Consumer Lending Angela Wolfe Kelley Executive Vice President, General Counsel and Corporate Secretary John V. Moran, cfa® Executive Vice President and Chief Financial Officer* Catherine M. Scarlett Executive Vice President and Chief Ethics and Human Resources Officer Joseph R. Stagliano Executive Vice President, President of Retail Community Banking and Chief Information Officer Amy Wiles Executive Vice President and Chief Credit and Risk Officer Operating Committee The following NBT leaders serve on the Operating Committee with the Executive Management Team. Annette L. Burns, Senior Vice President and Chief Accounting Officer* Leonard P. Chinski, Senior Vice President and Director of Audit Jeffrey S. Delepine II, Senior Vice President, Chief Compliance Officer and Chief Diversity Officer Kurt T. Edwards, Senior Vice President and Chief Consumer Credit Officer Dawn D. Gillette, Senior Vice President and Head of FinTech Partners and Specialty Lending Amy S. Hurta, Senior Vice President and Senior Director of Operations David A. Kavney, Regional President, Mohawk Valley David Krupski, Regional President, Capital Region Jeffrey D. Lake, Regional President, Greater Binghamton Tucker H. Lounsbury, cIc, President, NBT Insurance Agency, llc Stephen P. Lubelczyk, President of New England Mark R. Mershon, Corporate Senior Vice President and Treasurer Richard J. Shirtz, Regional President, Central New York David R. Theleman, Senior Vice President, Chief Commercial Credit Officer stockholder information NBT Bank Honorary Directors Richard Chojnowski Daryl R. Forsythe Paul D. Horger, Esq. Janet H. Ingraham Van Ness D. Robinson Paul M. Solomon Paul O. Stillman Additional information regarding our Executive Management Team and Board of Directors can be found in the proxy statement for our 2021 Annual Meeting of Stockholders. EPIC Retirement Plan Services Manuel Marques, cpc, qpa, qka, qpfc, aIf® President NBT Insurance Agency, llc Tucker H. Lounsbury, cIc President Board of Directors Martin A. Dietrich Chairman John H. Watt, Jr. President and Chief Executive Officer Johanna R. Ames Patricia T. Civil Timothy E. Delaney James H. Douglas Andrew S. Kowalczyk, III, Esq. John C. Mitchell V. Daniel Robinson, II Matthew J. Salanger Joseph A. Santangelo Lowell A. Seifter, Esq. Robert A. Wadsworth Jack H. Webb Regional Presidents Andreas A. Kapetanopoulos Connecticut David A. Kavney Mohawk Valley David Krupski Capital Region Jeffrey D. Lake Greater Binghamton Stephen P. Lubelczyk New Hampshire Richard J. Shirtz Central New York Kimberly J. Twitchell Maine Daniel P. Werme Vermont and Massachusetts 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. Stockholder 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 * John Moran will resign from his position as CFO on May 7, 2021, and Annette Burns will become Interim CFO and serve on the Executive Management Team in that capacity. www.nbtbancorp.com | 800.NBT.BANK www.nbtinsurance.com www.nbtbank.com www.epicrps.com NBT BANCORP INC.NBTBNasdaq Global Select Market