From May 17 to 19, 2026, Brian Bird, president and chief executive officer, Crystal Lail, vice president and chief financial officer, Travis Meyer, director corporate development and investor relations officer, and Emilie Ng, treasurer, of NorthWestern Energy Group, Inc. d/b/a NorthWestern Energy (Nasdaq: NWE) (the “Company”) will be attending the AGA Financial Conference in Scottsdale, Arizona, and, beginning on May 18, 2026, hosting one-on-one meetings with existing and potential investors. During these meetings, they will be providing certain information concerning the Company in a slide presentation and will be affirming the Company's 2026 non-GAAP earnings guidance range of $3.68 to $3.83 per diluted share.