MDU RESOURCES GROUP INC

Regulatory Filings • Nov 20, 2025

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): November 20, 2025

MDU Resources Group, Inc.

(Exact name of registrant as specified in its charter)

Delaware	1-03480	30-1133956
(State or other jurisdiction of	(Commission File Number)	(IRS Employer Identification No.)
incorporation)

1200 West Century Avenue

P.O. Box 5650

Bismarck , North Dakota

(Address of principal executive offices)

58506
(Zip Code)

Registrant’s telephone number, including area code: ( 701 ) 530-1000

N/A
(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 Securities Exchange Act of 1934:

Title of each class	Trading Symbol(s)	Name of each exchange on which registered
Common Stock, par value $1.00 per share	MDU	New York Stock Exchange

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

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 7.01. Regulation FD Disclosure.

On November 20, 2025, MDU Resources Group, Inc. (the "Company") issued a news release announcing its five-year capital investment plan. A copy of the news release, which the Company is furnishing to the U.S. Securities and Exchange Commission, is attached as Exhibit 99 and incorporated herein by reference.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits.

Exhibit No.	Description
99	News release, dated November 20, 2025, announcing five-year capital investment plan.
104	Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURE

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

	MDU RESOURCES GROUP, INC.
Date: November 20, 2025	By: /s/ Jason L. Vollmer
	Jason L. Vollmer
	Chief Financial Officer