Results of Operations and Financial Condition. On August 6, 2026, MDU Resources Group, Inc. (the “Company”) issued a news release (the “News Release”) announcing its financial results for the second quarter of 2026. A copy of the News Release is furnished as Exhibit 99 to this Current Report on Form 8-K, which, in its entirety, is incorporated herein by reference. The Company is webcasting a conference call on August 6, 2026, to discuss its second quarter 2026 financial results, during which…

The filing details changes to the company's long-term performance-based incentive plan and does not involve any management movement.

Results of Operations and Financial Condition. On May 7, 2026, MDU Resources Group, Inc. (the “Company”) issued a news release (the “News Release”) announcing its financial results for the first quarter of 2026. A copy of the News Release is furnished as Exhibit 99 to this Current Report on Form 8-K, which, in its entirety, is incorporated herein by reference. The Company is webcasting a conference call on May 7, 2026, to discuss its first quarter 2026 financial results, during which the Comp…

Results of Operations and Financial Condition. On February 5, 2026, MDU Resources Group, Inc. (the “Company”) issued a news release (the “News Release”) announcing its financial results for the fourth quarter and full-year of 2025. A copy of the News Release is furnished as Exhibit 99 to this Current Report on Form 8-K, which, in its entirety, is incorporated herein by reference. The Company is webcasting a conference call on February 5, 2026 to discuss its fourth quarter and full-year 2025 f…

Entry into a Material Definitive Agreement. On January 15, 2026, WBI Energy Transmission, Inc. (“WBI”), an indirect subsidiary of MDU Resources Group, Inc. (the “Company”), entered into Amendment No. 1 to the Second Amended and Restated Note Purchase and Private Shelf Agreement (the “Private Shelf Amendment”), by and among WBI, PGIM, Inc. (“Prudential”), and the others purchasers named therein, to amend that certain Note Purchase and Private Shelf Agreement, originally dated as of December 23…

Creation of Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant The disclosure set forth above under

Entry into a Material Definitive Agreement. As previously disclosed, on December 3, 2025, MDU Resources Group, Inc. (the “Company”) entered into an Underwriting Agreement (the “Underwriting Agreement”) with Wells Fargo Securities, LLC, BofA Securities, Inc. and J.P. Morgan Securities, LLC, as representatives of the several underwriters named therein (the “Underwriters”), Wells Fargo Bank, National Association, Bank of America, N.A. and JPMorgan Chase Bank, National Association, New York Branc…

Other Events. On December 23, 2025, the Underwriters exercised in full their option to purchase the Additional Forward Shares pursuant to the Underwriting Agreement. All of the Forward Shares were borrowed from third parties and sold to the Underwriters by the Forward Sellers. The Offering has been registered under the Securities Act of 1933, as amended (the “Securities Act”), pursuant to the Company’s automatic shelf registration statement filed with the U.S. Securities and Exchange Commissi…

Creation of Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant The disclosure set forth above under

Entry into a Material Definitive Agreement. On December 11, 2025, MDU Resources Group, Inc. (the “Company”) entered into an Amended and Restated Credit Agreement (the “Credit Agreement”) with U.S. Bank National Association, as administrative agent (“U.S. Bank”), and the several lenders party thereto, as lenders (collectively, the “Lending Parties”), to amend and restate that certain Five-Year Revolving Credit Agreement (the “Previous Credit Agreement”), dated May 31, 2023, among the Company,…

Entry into a Material Definitive Agreement. On December 3, 2025, MDU Resources Group, Inc. (the “Company”) entered into separate forward sale agreements (the “Forward Sale Agreements”) with each of Wells Fargo Bank, National Association, Bank of America, N.A. and JPMorgan Chase Bank, National Association, New York Branch (the “Forward Purchasers”), relating to an aggregate of 10,152,284 shares (the “Forward Shares”) of the Company’s common stock, par value $1.00 per share (the “Common Stock”)…

of this Current Report on Form 8-K. The Forward Sale Agreements provide for settlement on a settlement date or dates to be specified at the Company’s discretion by December 6, 2027. On a settlement date or dates, if the Company decides to physically settle the Forward Sale Agreements, the Company will issue shares of Common Stock to the Forward Purchasers at the then-applicable forward sale price. The forward sale price will initially be $19.04 per share, which is the price at which the Under…

Results of Operations and Financial Condition. On November 6, 2025, MDU Resources Group, Inc. (the “Company”) issued a news release (the “News Release”) announcing its financial results for the third quarter of 2025. A copy of the News Release is furnished as Exhibit 99 to this Current Report on Form 8-K, which, in its entirety, is incorporated herein by reference. The Company is webcasting a conference call on November 6, 2025, to discuss its third quarter 2025 financial results, during whic…

Director — Charles M. Kelley and Tammy J. Miller: The filing discloses the routine election of two new independent directors to the board, which is a standard governance action rather than an executive departure.

Entry into a Material Definitive Agreement. On August 7, 2025, MDU Resources Group, Inc. (the “Company”) entered into a distribution agreement (the “Distribution Agreement”) with Wells Fargo Securities, LLC (“Wells Fargo”) and BofA Securities, Inc. (“BofA Securities” and, together with Wells Fargo, the “Agents” and “Forward Sellers”), and Bank of America, N.A. and Wells Fargo Bank, National Association (collectively, the “Forward Purchasers”) relating to the issuance, offer, and sale from tim…

Results of Operations and Financial Condition. On August 7, 2025, MDU Resources Group, Inc. (the “Company”) issued a news release (the “News Release”) announcing its financial results for the second quarter of 2025. A copy of the News Release is furnished as Exhibit 99 to this Current Report on Form 8-K, which, in its entirety, is incorporated herein by reference. The Company is webcasting a conference call on August 7, 2025, to discuss its second quarter 2025 financial results, during which…

The filing discloses the approval of a Long-Term Incentive Plan (compensatory arrangement) rather than a change in directors or officers.

Results of Operations and Financial Condition. On May 8, 2025, MDU Resources Group, Inc. (the "Company") issued a news release (the "News Release") announcing its financial results for the first quarter of 2025. A copy of the News Release is furnished as Exhibit 99 to this Current Report on Form 8-K, which, in its entirety, is incorporated herein by reference. The Company is webcasting a conference call on May 8, 2025, to discuss its first quarter 2025 financial results, during which the Comp…

Entry into a Material Definitive Agreement. On February 13, 2025, Montana-Dakota Utilities Co. (the “Buyer”), a Delaware corporation and wholly-owned subsidiary of MDU Resources Group, Inc. (the “Company”), entered into a definitive Purchase and Sale Agreement (the “Agreement”) with Badger Wind, LLC (the “Seller,” and together with the Buyer, the “Parties”), a Delaware limited liability company, and a subsidiary of Orsted Onshore North America, LLC. Pursuant to the terms of the Agreement, the…

Results of Operations and Financial Condition. On February 6, 2025, MDU Resources Group, Inc. (the “Company”) issued a news release (the “News Release”) announcing its financial results for the fourth quarter and full-year of 2024. A copy of the News Release is furnished as Exhibit 99 to this Current Report on Form 8-K, which, in its entirety, is incorporated herein by reference. The Company is webcasting a conference call on February 6, 2025 to discuss its fourth quarter and full-year 2024 f…

Director — Vernon A. Dosch: The filing discloses the election of a new independent director to the board, which is a routine governance event and not a departure of a senior executive.

Results of Operations and Financial Condition and

Entry into a Material Definitive Agreement. In connection with the Separation and in order to govern the relationship between the parties following the Separation and Distribution, on October 31, 2024, the Company entered into a Separation and Distribution Agreement, a Transition Services Agreement, a Tax Matters Agreement and an Employee Matters Agreement with Everus. A summary of the material terms of such agreements can be found in the section entitled “Certain Relationships and Related Pa…

Completion of Acquisition or Disposition of Assets. The description of the Distribution set forth above under the Explanatory Note,

Termination of a Material Definitive Agreement. In connection with the Separation and Distribution, on November 1, 2024, the Company made a voluntary prepayment of all outstanding loans and obligations pursuant to that certain Term Loan Agreement, dated as of May 31, 2023, among the Company, the lenders party thereto and U.S. Bank National Association, as administrative agent .