NISOURCE INC. — Form 8-K

NiSource Inc. issued $750 million aggregate principal amount of 6.250% Fixed-to-Fixed Reset Rate Junior Subordinated Notes due April 15, 2057, dated August 18, 2026, under a Fourth Supplemental Indenture with The Bank of New York Mellon as trustee. The notes bear interest at 6.250% annually until April 15, 2032 (First Reset Date), then reset every five years to the Five-year U.S. Treasury Rate plus 1.930% spread, with a floor of 6.250%. NiSource may defer interest payments for up to 20 consecutive semi-annual periods and has optional redemption rights beginning 90 days before the First Reset Date at par plus accrued interest, or at 100%, 101%, or 102% of principal under specified tax or rating agency events.