ALABAMA POWER CO

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D. C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

(ADelaware Corporation)

30 Ivan Allen Jr. Boulevard, N.W.

(404)506-5000

(An Alabama Corporation)

600 North 18th Street

Birmingham, Alabama 35203

(205)257-1000

(AGeorgia Corporation)

241 Ralph McGill Boulevard, N.E.

(404)506-6526

(AMississippi Corporation)

2992 West Beach Boulevard

Gulfport, Mississippi 39501

(228)864-1211

(ADelaware Corporation)

30 Ivan Allen Jr. Boulevard, N.W.

(404)506-5000

(AGeorgia Corporation)

725 W. Peachtree Street, N.E.

(404)584-4000

The names and addresses of the registrants have not changed since the last report.

This combined Form 8-K is furnished separately by six registrants: The Southern Company, Alabama Power Company, Georgia Power Company, Mississippi Power Company, Southern Power Company and Southern Company Gas. Information contained herein relating to each registrant is furnished by each registrant solely on its own behalf. Each registrant makes no representation as to information relating to the other registrants.

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrants under any of the following provisions:

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). (Response applicable to each registrant)

Emerging growth company☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

The information in this Current Report on Form 8-K, including the exhibits attached hereto, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities under that Section. Furthermore, such information, including the exhibits attached hereto, shall not be deemed to be incorporated by reference in any filing under the Securities Act of 1933, as amended, except as shall be expressly set forth by specific reference in such filing.

On November 5, 2026, The Southern Company (“Southern Company”) issued a press release regarding its earnings for the three-month and nine-month periods ended September 30, 2026, including certain additional information regarding the financial results for such periods. A copy of this release is being furnished as Exhibit 99 to this Current Report on Form 8-K.

Use of Non-GAAP Financial Measures

Exhibit 99 to this Current Report on Form 8-K includes earnings and earnings per share in accordance with generally accepted accounting principles (“GAAP”) for the three-month and nine-month periods ended September 30, 2026 and 2025. The exhibit also includes earnings and earnings per share (1) for the three-month and nine-month periods ended September 30, 2026 and 2025, excluding accelerated depreciation and decommissioning costs related to the repowering of certain wind facilities at Southern Power Company, (2) for the three-month and nine-month periods ended September 30, 2026 and the nine-month period ended September 30, 2025, excluding costs associated with the extinguishment of debt at Southern Company, (3) for the three-month and nine-month periods ended September 30, 2026, excluding an estimated loss at Southern Company Gas related to costs associated with Nicor Gas capital investments disallowed by the Illinois Commerce Commission, (4) for the nine-month period ended September 30, 2026 and the three-month and nine-month periods ended September 30, 2025, excluding charges (net of salvage proceeds) and credits, associated legal expenses (net of insurance recoveries), and tax impacts related to plants under construction, (5) for the nine-month period ended September 30, 2026, excluding an income tax refund and related contingency fee expenses at Southern Company Gas, and (6) for the three-month and nine-month periods ended September 30, 2025, excluding disposition impacts related to the sale of a multi-use commercial facility development at Alabama Power Company. The attached exhibit includes additional information regarding these excluded items, as well as reconciliations of each non-GAAP financial measure to the most comparable financial measure under GAAP. Southern Company believes the presentation of earnings and earnings per share, excluding these items, is useful to investors because it provides investors with additional information to evaluate the performance of Southern Company’s ongoing business activities. Southern Company management also uses earnings and earnings per share, excluding the effect of these items, to evaluate the performance of Southern Company’s ongoing business activities. The presentation of this additional information is not meant to be considered a substitute for financial measures prepared in accordance with GAAP.

Exhibits

Exhibit 99 contains business segment information for Alabama Power Company, Georgia Power Company, Mississippi Power Company, Southern Power Company and Southern Company Gas. Accordingly, this report is also being furnished on behalf of each such registrant.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, each of the registrants has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.