MDU RESOURCES GROUP INC

Please refer to the Company's risk factors that are disclosed in Part I, Item 1A. Risk Factors in the 2024 Annual Report that could be materially harmful to the Company's business, prospects, financial condition or financial results if they occur. At September 30, 2025, there were no material changes to the Company's risk factors provided in Part I, Item 1A. Risk Factors in the 2024 Annual Report other than as set forth below.

Tariffs and changes in trade policy could negatively impact the Company's operations.

The United States government has recently implemented changes to trade policy and introduced tariffs on a range of products from certain countries, in addition to applying baseline tariffs on imports from most countries. These actions have created uncertainty in global markets and have increased and may continue to increase the cost of raw materials, commodities, supplies and equipment purchased by the Company. Additionally, the tariff and trade policy changes could cause supply chain disruptions and delays in sourcing materials and equipment which could delay large capital projects and negatively impact the Company’s financial condition and results of operations. If the Company's regulators do not determine the increased costs are prudent, or otherwise disallow certain costs, it could affect the Company’s ability to recover the cost increases through rates or on a timely basis which could adversely affect the Company's financial condition and results of operations.