Acquisitions and Divestitures	3 Months Ended
Dec. 31, 2025
Business Combination [Abstract]
Acquisitions and Divestitures	12. ACQUISITIONS AND DIVESTITURES Divestiture On January 1, 2026, after the close of the reporting period, the Company completed the sale of a non‑core equity interest that was outside its reportable segments. The investment had previously been accounted for under the equity method and carried an immaterial value. The Company received approximately $30.0 in cash proceeds from the sale and expect to recognize a pre-tax gain in its second quarter of fiscal 2026. Pending Acquisition On July 27, 2025, Spire entered into an agreement with Piedmont Natural Gas, a wholly-owned subsidiary of Duke Energy, to acquire its Tennessee natural gas business (“Piedmont Tennessee Transaction”). The purchase price is $2.48 billion in cash, subject to customary adjustments, including adjustments for net working capital, regulatory assets and liabilities, and capital expenditures at closing. Spire expects to fund the purchase price and related transaction and financing costs with: • $900.0 aggregate principal amount of its 6.250% Series A and 6.450% Series B junior subordinated notes due 2056, issued on November 24, 2025; • $825.0 aggregate principal amount of senior unsecured notes to be issued by Spire Tennessee upon closing of the Piedmont Tennessee Transaction through private placements pursuant to a master note purchase agreement dated December 17, 2025; and • a draw of approximately $725.0 under a bridge facility upon the closing of the Piedmont Tennessee Transaction. The Company entered into a committed senior unsecured bridge facility on August 22, 2025, provided by a syndicate of banks led by BMO Capital Markets. At December 31, 2025, the facility provided up to $725.0 of committed capacity, consisting of $125.0 bridge term loan and $600.0 delayed draw term loan. The loan bears interest at Adjusted Term SOFR plus 1.375% or Base Rate Plus 0.375% and matures 364 days after funding. As of December 31, 2025, the facility remains undrawn. While these issuances and the initial bridge draw will fund the acquisition at closing, the Company expects to subsequently refinance the bridge borrowings and optimize its capital structure through a balanced mix of debt, equity, and hybrid securities. In connection with the financing plan, Spire is considering selling certain non-core assets to help fund the acquisition. Any sales would be subject to board approval and customary closing conditions, including regulatory approval. The Company expects the acquisition to significantly increase Spire’s scale of regulated business in one of the fastest growing regions in the U.S., expand regulatory diversity and provide accretive earnings and supports dividend growth. Upon closing, Piedmont’s Tennessee business will operate as Spire Tennessee. The Piedmont Tennessee Transaction is expected to close in the first quarter of calendar 2026, subject to customary closing conditions, including approval by the Tennessee Public Utility Commission (“TPUC”). On October 31, 2025, FERC approved the transfer of gas supply contracts to Spire. The applicable waiting period under the Hart-Scott-Rodino Antitrust Improvements Act expired without objection, satisfying one of the key regulatory requirements for the transaction.

Acquisitions and Divestitures

3 Months Ended

Dec. 31, 2025

12. ACQUISITIONS AND DIVESTITURES

Divestiture

On January 1, 2026, after the close of the reporting period, the Company completed the sale of a non‑core equity interest that was outside its reportable segments. The investment had previously been accounted for under the equity method and carried an immaterial value. The Company received approximately $30.0 in cash proceeds from the sale and expect to recognize a pre-tax gain in its second quarter of fiscal 2026.

Pending Acquisition

On July 27, 2025, Spire entered into an agreement with Piedmont Natural Gas, a wholly-owned subsidiary of Duke Energy, to acquire its Tennessee natural gas business (“Piedmont Tennessee Transaction”). The purchase price is $2.48 billion in cash, subject to customary adjustments, including adjustments for net working capital, regulatory assets and liabilities, and capital expenditures at closing.

Spire expects to fund the purchase price and related transaction and financing costs with:

•

$900.0 aggregate principal amount of its 6.250% Series A and 6.450% Series B junior subordinated notes due 2056, issued on November 24, 2025;

•

$825.0 aggregate principal amount of senior unsecured notes to be issued by Spire Tennessee upon closing of the Piedmont Tennessee Transaction through private placements pursuant to a master note purchase agreement dated December 17, 2025; and

•

a draw of approximately $725.0 under a bridge facility upon the closing of the Piedmont Tennessee Transaction.

The Company entered into a committed senior unsecured bridge facility on August 22, 2025, provided by a syndicate of banks led by BMO Capital Markets. At December 31, 2025, the facility provided up to $725.0 of committed capacity, consisting of $125.0 bridge term loan and $600.0 delayed draw term loan. The loan bears interest at Adjusted Term SOFR

plus 1.375% or Base Rate Plus 0.375% and matures 364 days after funding. As of December 31, 2025, the facility remains undrawn. While these issuances and the initial bridge draw will fund the acquisition at closing, the Company expects to subsequently refinance the bridge borrowings and optimize its capital structure through a balanced mix of debt, equity, and hybrid securities.

In connection with the financing plan, Spire is considering selling certain non-core assets to help fund the acquisition. Any sales would be subject to board approval and customary closing conditions, including regulatory approval.

The Company expects the acquisition to significantly increase Spire’s scale of regulated business in one of the fastest growing regions in the U.S., expand regulatory diversity and provide accretive earnings and supports dividend growth. Upon closing, Piedmont’s Tennessee business will operate as Spire Tennessee.

The Piedmont Tennessee Transaction is expected to close in the first quarter of calendar 2026, subject to customary closing conditions, including approval by the Tennessee Public Utility Commission (“TPUC”). On October 31, 2025, FERC approved the transfer of gas supply contracts to Spire. The applicable waiting period under the Hart-Scott-Rodino Antitrust Improvements Act expired without objection, satisfying one of the key regulatory requirements for the transaction.