UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE FISCAL YEAR ENDED DECEMBER 31, 2018 COMMISSION FILE NUMBER: 0-14703 NBT BANCORP INC. (Exact name of registrant as specified in its charter) (State or other jurisdiction of incorporation or organization) (IRS Employer Identification No.) Delaware 16-1268674 52 SOUTH BROAD STREET NORWICH, NEW YORK 13815 (Address of principal executive of ...