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

NorthWestern Energy Group, Inc.

(Exact name of registrant as specified in its charter)

Delaware

000-56598

93-2020320

(State or other jurisdiction of
incorporation or organization)

(Commission File Number)

(I.R.S. Employer Identification No.)

3010 W. 69th Street

Sioux Falls

South Dakota

57108

(Address of principal executive offices)

(Zip Code)

Registrant’s telephone number, including area code: 605-978-2900

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 (see General Instruction A.2. below):

☐ 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:


Registrant	Title of each class	Trading Symbol(s)	Name of each exchange on which registered
NorthWestern Energy Group, Inc.	Common stock	NWE	Nasdaq Stock Market LLC

Indicate by check mark whether the registrant is an emerging growth company as defined in 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 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

(b) Resignation of Named Executive Officer

On October 27, 2025, John Hines, Vice President — Supply / Montana Government Affairs of NorthWestern Energy Group, Inc. (Nasdaq: NWE) (the "Company"), announced that he will retire from his position with the Company as of February 2, 2026.

The Company appreciates the 20 years of service, including nearly 15 years in his Vice President role, Mr. Hines has dedicated to shaping the Company’s energy future. His leadership helped rebuild the Company's electric portfolio in Montana following deregulation and maintain resource adequacy in Montana and South Dakota while also modernizing older and less efficient generators. The Company is deeply grateful for his leadership, integrity, and commitment to balancing the needs of shareholders, customers, and employees.

Item 9.01 Financial Statements and Exhibits.


Exhibit No.						Description of Document
104						Cover Page Interactive Data File – the cover page XBRL tags are embedded within the Inline XBRL document

Signatures

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.


						NorthWestern Energy Group, Inc.

			By:			/s/ Timothy P. Olson
						Timothy P. Olson
						Corporate Secretary

Date: October 31, 2025

NorthWestern Energy Group, Inc. 8-K