UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 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, 2023 Or ☐ Transition Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 For the transition period from ____________________ to ____________________ Commission file number 0-10592 TRUSTCO BANK CORP NY (Exact name of registrant as specified in its charter) NEW YORK 14-1630287 (S ...