ALABAMA POWER CO

(L)SEGMENT AND RELATED INFORMATION

See Note 16 to the financial statements in Item 8 of the Form 10-K for additional information.

The primary businesses of the Southern Company system are electricity sales by the traditional electric operating companies and Southern Power and the distribution of natural gas by Southern Company Gas. The traditional electric operating companies are vertically integrated utilities providing electric service inthree Southeastern states. Southern Power develops, constructs, acquires, owns, operates, and manages power generation assets, including renewable energy and battery energy storage projects, and sells electricity at market-based rates in the wholesale market. Southern Company Gas distributes natural gas through its natural gas distribution utilities and is involved in several other complementary businesses including gas pipeline investments and gas marketing services.

Southern Company's reportable business segments are the sale of electricity by the traditional electric operating companies, the sale of electricity in the competitive wholesale market by Southern Power, and the sale of natural gas and other complementary products and services by Southern Company Gas. While the traditional electric operating companies represent three separate operating segments, they are vertically integrated utilities providing electric service to retail customers, as well as wholesale customers, in the Southeast and have been aggregated intoone reportable segment. Revenues from sales by Southern Power to the traditional electric operating companies were $112 million and $341 million for the three and nine months ended September 30, 2025, respectively, and $102 million and $280 million for the three and nine months ended September 30, 2024, respectively. Revenues from sales of natural gas from Southern Company Gas to the traditional electric operating companies and Southern Power were immaterial for all periods presented. The "All Other" column includes the Southern Company parent entity, which does not allocate operating expenses to business segments. Also, this category includes segments below the quantitative threshold for separate disclosure. These segments include providing distributed energy and resilience solutions and deploying microgrids for commercial, industrial, governmental, and utility customers, as well as investments in telecommunications. All other inter-segment revenues are not material.

Southern Company's CODM utilizes segment net income, including variances to budget and forecasts, to assess performance and is not provided with segment expense information. To achieve the consolidated net income goal, Southern Company's CODM sets net income expectations for each operating segment, which is expected to monitor its expenses in order to achieve its assigned net income target. Therefore, Southern Company has no reportable significant segment expenses.

Financial data for business segments for the three and nine months ended September 30, 2025 and 2024 was as follows:

(a)Primarily consists of fuel, purchased power, cost of natural gas, cost of other sales, other operations and maintenance, taxes other than income taxes, AFUDC equity, non-service cost-related retirement benefits income, and net income (loss) attributable to noncontrolling interests.

(b)For the traditional electric operating companies, includes pre-tax credits to income at Georgia Power related to the estimated probable loss associated with the completion of Plant Vogtle Units 3 and 4 of $33 million ($25 million after tax) for the three and nine months ended September 30, 2025 and $21 million ($16 million after tax) for the nine months ended September 30, 2024. Also includes a pre-tax gain at Georgia Power of approximately $114 million ($84 million after tax) for the nine months ended September 30, 2024 related to the sale of transmission line assets under the integrated transmission system agreement. See Note 2 to the financial statements under "Georgia Power" in Item 8 of the Form 10-K for additional information.

(c)For Southern Power, includes accelerated depreciation related to the repowering of the Kay Wind, Grant Plains, Grant Wind, and Wake Wind facilities of $112 million ($80 million after tax, net of noncontrolling interest impacts) and $181 million ($130 million after tax, net of noncontrolling interest impacts) for the three and nine months ended September 30, 2025, respectively. See Note (K) under "Southern Power – Wind Repowering Projects" herein and Note 15 to the financial statements under "Southern Power – Development Projects" in Item 8 of the Form 10-K for additional information.

(d)Attributable to Southern Company.

(e)For All Other, includes a pre-tax loss of $129 million ($97 million after tax) associated with the extinguishment of debt at the parent company. See Note (F) under "Convertible Senior Notes" herein for additional information.

(f)For the traditional electric operating companies, includes a pre-tax impairment loss at Alabama Power of $36 million ($27 million after tax) related to Alabama Power discontinuing the development of a multi-use commercial facility, which was sold in July 2025. See Note 1 to the financial statements under "Impairment of Long-Lived Assets" in Item 8 of the Form 10-K for additional information.

Traditional Electric Operating Companies

Each of the traditional electric operating companies' single reportable business segment is the sale of electricity.

Alabama Power and Georgia Power have identified utility operations and maintenance expenses as significant segment expenses provided to their CODMs. Utility operations and maintenance expenses is calculated as other operations and maintenance, as reflected on the statements of income, less expenses from unregulated products and services, losses (gains) on asset dispositions, impairment charges, amortization of cloud software, and, for Georgia Power, charges (credits) for estimated loss on Plant Vogtle Units 3 and 4. Alabama Power's utility operations and maintenance expenses are disaggregated into expenses related to Rate RSE and Rate CNP Compliance. See Note 2 to the financial statements under "Alabama Power" in Item 8 of the Form 10-K for additional information.

During the third quarter 2025, Mississippi Power updated the information provided to its CODM. As a result, Mississippi Power has identified certain operational and environmental compliance expenses as significant segment expenses and has recast prior period information to conform to the current period presentation.

Financial data for significant segment expenses and other segment information for the three and nine months ended September 30, 2025 and 2024 was as follows:

(a)Primarily consists of fuel, purchased power, expenses from unregulated products and services, losses (gains) on asset dispositions, amortization of cloud software, taxes other than income taxes, AFUDC equity, and non-service cost-related retirement benefits income. For Alabama Power, includes impairment charges. For Georgia Power, includes credits for estimated loss on Plant Vogtle Units 3 and 4. For Mississippi Power, includes employee benefit expenses and affiliate billings. Also includes earnings from equity method investments, which were immaterial for all periods presented.

(b)For the three and nine months ended September 30, 2024, includes a pre-tax impairment loss of $36 million ($27 million after tax) related to Alabama Power discontinuing the development of a multi-use commercial facility, which was sold in July 2025. See Note 1 to the financial statements under "Impairment of Long-Lived Assets" in Item 8 of the Form 10-K for additional information.

(c)Includes pre-tax credits to income related to the estimated probable loss associated with the completion of Plant Vogtle Units 3 and 4 of $33 million ($25 million after tax) for the three and nine months ended September 30, 2025 and $21 million ($16 million after tax) for the nine months ended September 30, 2024. Also includes a pre-tax gain of approximately $114 million ($84 million after tax) for the nine months ended September 30, 2024 related to the sale of transmission line assets under the integrated transmission system agreement. See Note 2 to the financial statements under "Georgia Power" in Item 8 of the Form 10-K for additional information.

(d)Consists of certain operations and maintenance expenses related to PEP and the MRA tariff, including labor costs, materials, contract services, and other normal operational costs. See Note (B) under "Mississippi Power" herein and Note 2 to the financial statements under "Mississippi Power" in Item 8 of the Form 10-K for additional information regarding PEP and the MRA tariff.

(e)Consists of environmental compliance expenses related to ECO Plan and the MRA tariff. See Note (B) under "Mississippi Power" herein and Note 2 to the financial statements under "Mississippi Power" in Item 8 of the Form 10-K for additional information regarding ECO Plan and the MRA tariff.

Southern Power's single reportable business segment is the sale of electricity in the competitive wholesale market. Southern Power's CODM utilizes segment expense information in the form of variances to budget to assess performance; therefore, Southern Power has no reportable significant segment expenses.

Financial data for segment information for the three and nine months ended September 30, 2025 and 2024 was as follows:

(a)Primarily consists of fuel, purchased power, other operations and maintenance, taxes other than income taxes, and net income (loss) attributable to noncontrolling interests.

(b)For the three and nine months ended September 30, 2025, includes accelerated depreciation of $112 million ($80 million after tax, net of noncontrolling interest impacts) and $181 million ($130 million after tax, net of noncontrolling interest impacts), respectively, related to the repowering of the Kay Wind, Grant Plains, Grant Wind, and Wake Wind facilities. See Note (K) under "Southern Power – Wind Repowering Projects" herein and Note 15 to the financial statements under "Southern Power – Development Projects" in Item 8 of the Form 10-K for additional information.

(c)Southern Power had no earnings from equity method investments for any period presented.

Southern Company Gas manages its business through three reportable segments – gas distribution operations, gas pipeline investments, and gas marketing services. The non-reportable segments are combined and presented as all other.

The gas distribution operations segment is the largest component of Southern Company Gas' business and includes natural gas local distribution utilities that construct, manage, and maintain intrastate natural gas pipelines and gas distribution facilities infour states.

The gas pipeline investments segment consists of joint ventures in natural gas pipeline investments including a 50% interest in SNG and a 50% joint ownership interest in the Dalton Pipeline. These natural gas pipelines enable the provision of diverse sources of natural gas supplies to the customers of Southern Company Gas. See Note 7 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information.

The gas marketing services segment provides natural gas marketing to end-use customers primarily in Georgia through SouthStar.

The "All Other" column includes segments and subsidiaries that fall below the quantitative threshold for separate disclosure.

Southern Company Gas' CODM utilizes segment expense information in the form of variances to budget to assess performance; therefore, Southern Company Gas has no reportable significant segment expenses.

Financial data for business segments for the three and nine months ended September 30, 2025 and 2024 was as follows:

(*)Primarily consists of cost of natural gas, other operations and maintenance, taxes other than income taxes, AFUDC equity, and non-service cost-related retirement benefits income.