MDU Resources Reports Director Departure and Shareholder Votes

BISMARCK, N.D., May 13, 2026 — MDU Resources Group Inc. (NYSE: MDU) reported the departure of a board member along with voting outcomes from its annual shareholder meeting, according to an 8-K filed with the SEC on May 13, 2026.

The filing covers Item 5.02 on the departure or election of directors or principal officers, Item 5.05, Item 5.07 on the submission of matters to a vote of security holders, and Item 9.01 on financial statements and exhibits. MDU Resources Group Inc. is a Fortune 500 company with operations in regulated energy delivery and construction materials and services across 48 states.

Under Item 5.02, one director departed the board. The filing identifies the individual, role, effective date and any cited cause as required by SEC rules for officer and director changes. The departure alters the board's composition from its prior state and takes effect on the date stated in the filing.

Item 5.07 details specific proposals voted on by shareholders, including the precise vote tallies for each matter.

The operational change requires the company to update its board structure and committee assignments. It also obligates MDU to file any additional Form 8-K or proxy-related disclosures if further elections occur to fill the vacancy. Standard SEC deadlines now apply for any subsequent Form 4 or Form 5 filings tied to the departing director's holdings, and the board must operate with its new membership for all governance decisions until a replacement is named.

Downstream, the departure initiates the board's nomination and election process under the company's bylaws and SEC rules governing director vacancies. Shareholders who rely on the proxy statement for voting will see the updated board list in the next definitive proxy filing.

If the departed director served on key committees such as audit or compensation, those committees must reconstitute to maintain compliance with NYSE listing standards and SEC independence requirements. The company must also reflect the change in its next annual report or quarterly filing that discloses board membership.

This filing constitutes the primary public record of the board change and vote results. It follows standard practice for public companies to report such events within four business days under SEC rules. The Items section language in the 8-K directly supplies the names, dates, vote counts and effective timing that govern all subsequent compliance steps.