UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): October 27, 2025

NBT BANCORP INC.

(Exact name of registrant as specified in its charter)

Delaware	000-14703	16-1268674
(State or other jurisdiction of incorporation or organization)	(Commission File Number)	(I.R.S. Employer Identification No.)

52 South Broad Street, Norwich, New York 13815

(Address of principal executive offices) (Zip Code)

Registrant’s telephone number, including area code: (607) 337-2265

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐	Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐	Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐	Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐	Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of class	Trading Symbol	Name of exchange on which registered
Common Stock, par value $0.01 per share	NBTB	The NASDAQ Stock Market LLC

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02

Results of Operations and Financial Condition

On October 27, 2025, NBT Bancorp Inc. issued a press release describing its results of operations for the quarter ended September 30, 2025. That press release is furnished as Exhibit 99.1 hereto. A conference call will be held at 10:00 a.m. Eastern Time on Tuesday, October 28, 2025, to review the third quarter 2025 financial results. The audio webcast link, along with the corresponding presentation slides, will be available on the Event Calendar page of the Company’s website at www.nbtbancorp.com.

Item 9.01

Financial Statements and Exhibits.

(a)	Not applicable.

(b)	Not applicable.

(c)	Not applicable.

(d)

Exhibits.

Exhibit No.		Description
99.1		Press release of NBT Bancorp Inc. October 27, 2025
104		Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	NBT BANCORP INC.

Date: October 27, 2025	By:	/s/ Annette L. Burns
		Annette L. Burns
		Executive Vice President and Chief Financial Officer

NBT BANCORP INC 8-K