# Alliant Energy Corp: Form 10-Q for the period ended Sep 30, 2026

- Company: [Alliant Energy Corp](/companies/lnt.md) (CIK 352541)
- Form: 10-Q
- Filed: 2026-10-30
- Accepted by EDGAR: Oct 30, 2026, 11:21 ET
- Period: 2026-09-30
- Accession: 0000352541-26-000047
- Inline XBRL: yes
- Main document: https://www.sec.gov/Archives/edgar/data/352541/000035254126000047/lnt-20260930.htm
- All documents and exhibits: https://www.sec.gov/Archives/edgar/data/352541/000035254126000047/

## Management's discussion and analysis

As filed, 49,449 characters.

This MDA includes information relating to Alliant Energy, and IPL and WPL (collectively, the Utilities), as well as ATC Holdings, AEF and Corporate Services. Where appropriate, information relating to a specific entity has been segregated and labeled as such. The following discussion and analysis should be read in conjunction with the Financial Statements and the Notes included in this report, as well as the financial statements, notes and MDA included in the 2025 Form 10-K. Unless otherwise noted, all “per share” references in MDA refer to earnings per diluted share.

### 2026 HIGHLIGHTS

Key highlights since the filing of the 2025 Form 10-K include the following:

### Customer Investments:

- Over the next six years, Alliant Energy currently plans to develop and/or acquire energy resources to meet the growing energy demands of its customers, including approximately 2,800 MW of new natural gas resources, approximately 1,300 MW of new energy storage, approximately 1,300 MW of new renewable generation, improvements of approximately 280 MW at existing natural gas-fired EGUs, and refurbishments at approximately 450 MW of existing wind farms. Alliant Energy is currently evaluating the impact of potential additional large load growth customers and MISO’s resource adequacy requirements on its resource plans and will update these generation investment plans as needed in the future. Estimated capital expenditures for these planned projects for 2026 through 2030 are included in the “Generation” section in the construction and acquisition table in “Liquidity and Capital Resources.” Information on IPL’s and WPL’s regulatory filings and/or approvals for future generation and energy storage projects are as follows:
- In March 2026, the IUC approved advance rate-making principles for IPL for up to 1,000 MW of new wind generation in Iowa. The rate-making principles approved include a fixed cost cap of $3,020/kilowatt, including AFUDC and transmission costs, among other costs. IPL’s return on common equity will be the same as other assets without advance rate-making principles for the purposes of setting future rates and IPL’s blended return on common equity, which will be updated each year, will be used for IPL’s retail electric earnings sharing mechanism calculation.
- In March 2026, WPL filed a certificate of authority application with the PSCW for approval to construct, own and install equipment that will maintain and increase the capacity and efficiency of its Riverside Energy Center. A decision from the PSCW is currently expected in the second quarter of 2027.
- In April 2026, IPL filed a certificate of public convenience, use and necessity (GCU Certificate) application with the IUC for approval to construct, own and operate an approximately 720 MW simple-cycle natural gas-fired EGU in Linn County, Iowa. A decision from the IUC is currently expected in the first quarter of 2027.
- In July 2026, IPL filed a GCU Certificate application with the IUC for approval to construct, own and operate an approximately 1,200 MW simple-cycle natural gas-fired EGU near the site of its Emery Generating Station, known as the Riverhawk Energy Center. A decision from the IUC is currently expected in the second quarter of 2027.
- In July 2026, the PSCW issued an order authorizing WPL to construct, own and operate the Bent Tree North EGU, an approximately 153 MW wind farm.
- In July 2026, IPL filed a GCU Certificate application with the IUC for approval to construct, own and operate up to 175 MW of energy storage at the site of its Marshalltown Generating Station. A decision from the IUC is currently expected in the fourth quarter of 2026.
- In August 2026, the IUC issued an order authorizing IPL to construct, own and operate up to an additional 125 MW of energy storage at the site of its Whispering Willow - North wind farm. The order approved an increase to energy storage capacity at the site from the 75 MW previously approved to approximately 200 MW.
- In September 2026, IPL filed a GCU Certificate application with the IUC for approval to construct, own and operate up to 170 MW of energy storage at the site of its English Farms wind farm. A decision from the IUC is currently expected in the first quarter of 2027.
- In October 2026, the PSCW issued an order authorizing WPL to construct a 2 billion cubic feet liquefied natural gas facility in Rock County, Wisconsin.
- In June 2026, the Neenah Unit 2 and Sheboygan Falls Unit 2 advanced gas path projects were completed, which increased the efficiency and capacity at each of these EGUs.
- WPL currently plans to continue coal operations at Edgewater Unit 5 (414 MW) and Columbia Units 1 and 2 (595 MW in aggregate) at least through 2030 and will continue to monitor environmental regulatory developments and evaluate potential alternatives for these facilities to support system reliability, affordability and customer energy needs.
- IPL and WPL have incurred development costs associated with certain renewable generation projects. Development of these projects is dependent upon customer interest, market conditions, regulatory approvals, permitting requirements, interconnection arrangements and other economic and operational factors. Changes in these factors may result in delays, modifications or discontinuation of development activities and could result in some or all of the related project development costs not being recoverable.

### Rate Matters:

Large Load Tariff – In connection with its June 2026 approval of an individual customer rate (ICR), the PSCW directed WPL to file a large load tariff applicable to all customers with demand requirements of 100 MW or greater. The requirement to file a large load tariff did not affect the PSCW’s June 2026 approval of the ICR. In addition, customers served under approved ICRs must be treated as a separate customer class for purposes of future cost-of-service studies in WPL’s next retail electric rate review. Refer to “Growing Customer Demand” for additional information regarding the approved ICR. In September 2026, WPL filed an application with the PSCW for approval of a large load tariff. The large load tariff specifies the rates, terms and conditions applicable to customers meeting the applicable threshold and describes the standards and protections WPL will apply when evaluating electric service agreements with large load growth customers. The proposed tariff would require qualifying customers to commit to an initial service term of 15 years and includes minimum demand commitments, termination charges, customer reimbursement obligations and credit support requirements. The proposed tariff is intended to require customers receiving service under the tariff to pay the generation, distribution, transmission, operating and other costs associated with serving their load and is designed to help ensure such costs are not subsidized by or shifted to other customers. A decision from the PSCW is currently expected in the first half of 2027.

IPL’s Retail Electric and Gas Rate Reviews (October 2024 Through September 2025 Forward-looking Test Period) - In August 2026, the IUC issued an order for IPL’s retail electric and gas subsequent proceeding, ordering IPL to maintain its current retail electric rates and to reduce annual base rates by $3 million for retail residential gas customers effective on October 6, 2026. The IUC also opened a separate docket to gather information to review IPL’s management efficiency.

Planned Rate Review - WPL currently expects to file a retail electric and gas rate review with the PSCW in the second quarter of 2027 for the 2028/2029 forward-looking Test Period. The key drivers for the anticipated filing include revenue requirement impacts of increasing electric and gas rate base. Any rate changes granted from this pending request are expected to be effective on January 1, 2028, with a decision from the PSCW expected by the end of 2027.

### Growing Customer Demand:

- In April 2026, IPL entered into an electric service agreement with a customer who currently expects to build a data center in IPL’s service territory. This electric service agreement includes contracted peak demand of approximately 370 MW. The actual timing and amount of increases in IPL’s load are subject to various factors, including interconnections and actual customer demand, and any executed or future agreements with customers are not expected to result in immediate increases in load. In October 2026, IPL filed a request with the IUC for approval of an ICR for a data center expected to be constructed in its service territory. A decision from the IUC is currently expected in the first quarter of 2027.
- In June 2026, the PSCW approved an ICR for a customer who is constructing a data center in WPL’s service territory, subject to certain conditions, including the recognition of demand revenue received prior to WPL’s next retail electric rate review through WPL’s retail electric fuel cost recovery mechanism. Refer to “Rate Matters” for additional information regarding the large load tariff requirements established by the PSCW in connection with its approval of the ICR.

### Environmental Matters:

Coal Combustion Residuals (CCR) Rule - In April 2026, the EPA proposed a rule that would significantly reduce the scope of the CCR Rule, which is currently anticipated to be finalized by the end of 2026. Alliant Energy, IPL and WPL continue to evaluate the revised CCR Rule and are unable to predict with certainty the future outcome or impact of these updates, including resolution of ongoing litigation.

Effluent Limitation Guidelines and Standards (ELGs) - In May 2026, the EPA proposed changes to the 2024 ELG Rule, which are currently anticipated to be finalized by the end of 2026. The proposed rule would revise discharge limits for specific categories of wastewater from certain existing steam EGUs. If finalized, the revised limitations would be implemented in the wastewater discharge permits issued by state agencies to affected facilities. Alliant Energy, IPL and WPL continue to evaluate the revised 2024 ELG Rule and are unable to predict with certainty the future outcome or impact of these updates, including resolution of ongoing or potential litigation.

Clean Air Act Section 111(d) - In September 2026, the EPA finalized a rule repealing the Section 111(d) emission guidelines for existing fossil-fueled EGUs, which would have imposed compliance requirements beginning in 2030 for certain affected Alliant Energy, IPL and WPL generating facilities through measures such as retirement, enforceable limits on operations, co-firing with low-GHG fuels or carbon capture and storage technology. Alliant Energy, IPL and WPL are currently unable to predict with certainty the future outcome or impact of these matters, including resolution of ongoing or potential litigation.

Clean Air Act Section 111(b) - In September 2026, the EPA finalized a rule partially repealing the 2024 revised standards under Section 111(b), which established carbon dioxide (CO2) emission limits from certain new and reconstructed fossil-fueled EGU combustion turbines that commence operation after May 23, 2023 with a capacity greater than 25 MW. The partial repeal removes standards based on carbon capture and storage that would have been effective by January 1, 2032. However, standards requiring low-emitting fossil-fuels and highly efficient EGU design technology with best operation and maintenance practices remain in effect for certain newly constructed fossil-fueled EGUs. The EPA also issued a supplemental proposal that would rescind the greenhouse gas findings for fossil-fueled EGUs and repeal the remaining CO2 regulations for fossil-fueled EGUs under Section 111 of the Clean Air Act. Alliant Energy, IPL and WPL are currently unable to predict with certainty the future outcome or impact of these matters, including resolution of ongoing or potential litigation.

### Legislative Matters:

- In April 2026, the State of Wisconsin enacted 2025 Wisconsin Act 193, which requires utilities to include their capacity costs and revenues in their annual fuel cost plans. The most significant provisions of the legislation for Alliant Energy and WPL are the requirement that fuel cost calculations in approved fuel cost plans account for both the cost of purchasing capacity and the revenue generated from selling it. The legislation applies to fuel cost plans filed on or after January 1, 2027.
- In October 2026, legislation was enacted revising the Major Economic Growth Attraction program in Iowa for projects located in rural counties. The legislation allows the Iowa Economic Development Authority to provide either an investment tax credit of up to 10% of a qualifying investment for a project located in a rural county or investment tax credits of up to 5% of qualifying investments for up to two projects. The most significant provision of this program for Alliant Energy encourages economic development in IPL’s service territory by supporting certain projects with capital investments greater than $1 billion and may support the development of certain large load growth projects, including the proposed construction of a steel plant in Southeast Iowa.

### Financings and Common Stock Dividends:

- Refer to “Results of Operations” for discussion of expected future issuances of common stock in 2026 through 2030 and common stock dividends in 2027, and expected future issuances and retirements of long-term debt by the end of 2027.
- In October 2026, IPL and WPL entered into loan guarantee agreements with the U.S. Department of Energy (DOE), who may guarantee borrowings of up to $3.5 billion and $1.6 billion, respectively. Refer to “U.S. Department of Energy Loan Guarantee Borrowings” in Liquidity and Capital Resources for further details.

### RESULTS OF OPERATIONS

**Financial Results Overview -** The table below includes diluted EPS for Utilities and Corporate Services, ATC Holdings, and Non-utility and Parent, which are non-GAAP financial measures. Alliant Energy believes these non-GAAP financial measures are useful to investors because they facilitate an understanding of performance and trends, and provide additional information about Alliant Energy’s operations on a basis consistent with the measures that management uses to manage its operations and evaluate its performance. Alliant Energy’s net income and diluted EPS attributable to Alliant Energy common shareowners for the three and nine months ended September 30 were as follows (dollars in millions, except per share amounts):

|  | For the Three Months Ended September 30, 2026 Income (Loss) | EPS | 2025 Income (Loss) | EPS | For the Nine Months Ended September 30, 2026 Income (Loss) | EPS | 2025 Income (Loss) | EPS |
| --- | ---: | ---: | ---: | ---: | ---: | ---: | ---: | ---: |
| Utilities and Corporate Services | **$412** | **$1.58** | $292 | $1.13 | **$775** | **$2.98** | $707 | $2.75 |
| ATC Holdings | **13** | **0.05** | 10 | 0.04 | **36** | **0.14** | 31 | 0.12 |
| Non-utility and Parent | **(27)** | **(0.11)** | (21) | (0.08) | **(19)** | **(0.08)** | (70) | (0.28) |
| Alliant Energy Consolidated | **$398** | **$1.52** | $281 | $1.09 | **$792** | **$3.04** | $668 | $2.59 |

Alliant Energy’s Utilities and Corporate Services net income increased by $120 million for the three-month period, primarily due to the timing of income taxes, higher revenue requirements from IPL’s and WPL’s capital investments, higher allowance for funds used during construction and higher retail electric sales. These items were partially offset by higher other operation and maintenance, financing and depreciation expenses.

Alliant Energy’s Non-utility and Parent net income decreased by $6 million for the three-month period, primarily due to the timing of income taxes and higher financing expense, partially offset by higher equity earnings from corporate venture investments and a state income tax apportionment charge in 2025.

Alliant Energy’s Utilities and Corporate Services net income increased by $68 million for the nine-month period, primarily due to higher revenue requirements from IPL’s and WPL’s capital investments, the timing of income taxes, higher allowance for funds used during construction and higher retail electric sales. These items were partially offset by higher other operation and maintenance, financing and depreciation expenses.

Alliant Energy’s Non-utility and Parent net income increased by $51 million for the nine-month period, primarily due to higher equity earnings from corporate venture investments, a state income tax apportionment benefit in 2026 and a state income tax apportionment charge in 2025, partially offset by higher financing expense.

**Net Income Variances -** The following items contributed to increased (decreased) net income for the three and nine months ended September 30, 2026 compared to the same periods in 2025 (in millions):

| Revenues: | Three Months Alliant Energy | IPL | WPL | Nine Months Alliant Energy | IPL | WPL |
| --- | ---: | ---: | ---: | ---: | ---: | ---: |
| Changes in electric utility (Refer to details below) | $78 | $23 | $55 | $123 | $44 | $79 |
| Changes in gas utility (Refer to details below) | 5 | 5 | — | 42 | 12 | 30 |
| Changes in other utility (Refer to Note 7 for details) | (11) | (11) | — | (31) | (32) | 1 |
| Changes in non-utility | 3 | — | — | 8 | — | — |
| Changes in total revenues | 75 | 17 | 55 | 142 | 24 | 110 |
| **Operating expenses:** |  |  |  |  |  |  |
| Changes in electric production fuel and purchased power (Refer to details below) | 17 | 17 | — | 42 | 15 | 27 |
| Changes in electric transmission service (Refer to details below) | (10) | (4) | (6) | (16) | 2 | (18) |
| Changes in cost of gas sold (Refer to details below) | (1) | (3) | 2 | (43) | (17) | (26) |
| Changes in other operation and maintenance (Refer to details below) | (24) | (4) | (19) | (88) | (34) | (51) |
| Changes in depreciation and amortization (Higher primarily due to energy storage and electric distribution placed in service in 2025) | (12) | (6) | (6) | (34) | (14) | (21) |
| Changes in taxes other than income taxes | (5) | (1) | (4) | (8) | (3) | (5) |
| Changes in total operating expenses | (35) | (1) | (33) | (147) | (51) | (94) |
| **Changes in operating income** | 40 | 16 | 22 | (5) | (27) | 16 |
| **Other income and deductions:** |  |  |  |  |  |  |
| Changes in interest expense (Higher primarily due to financings completed in 2026 and 2025) | (17) | (6) | (6) | (58) | (20) | (17) |
| Changes in equity income from unconsolidated investments, net (Refer to Note 4 for details) | 27 | — | — | 69 | — | — |
| Changes in allowance for funds used during construction (Primarily due to changes in levels of construction work in progress balances related to energy storage, gas generation and refurbishments of existing wind farms) | 14 | 11 | 3 | 34 | 28 | 6 |
| Changes in Other | 4 | — | 5 | 12 | 1 | 11 |
| Changes in total other income and deductions | 28 | 5 | 2 | 57 | 9 | — |
| **Changes in income before income taxes** | 68 | 21 | 24 | 52 | (18) | 16 |
| Changes in income taxes (Refer to Note 8 for details) | 49 | 65 | 9 | 72 | 54 | 14 |
| **Changes in net income** | $117 | $86 | $33 | $124 | $36 | $30 |

**Electric and Gas Revenues and Sales Summary -** Electric and gas revenues (in millions), and MWh and Dth sales (in thousands), for the three and nine months ended September 30 were as follows:

| Alliant Energy Three Months | Electric Revenues 2026 | 2025 | MWhs Sold 2026 | 2025 | Gas Revenues 2026 | 2025 | Dths Sold 2026 | 2025 |
| --- | ---: | ---: | ---: | ---: | ---: | ---: | ---: | ---: |
| Retail | **$1,055** | $996 | **7,146** | 6,974 | **$40** | $38 | **3,191** | 3,252 |
| Sales for resale: |  |  |  |  |  |  |  |  |
| Wholesale | **45** | 51 | **599** | 713 | **N/A** | N/A | **N/A** | N/A |
| Bulk power and other | **87** | 64 | **1,391** | 1,497 | **N/A** | N/A | **N/A** | N/A |
| Transportation/Other | **15** | 13 | **14** | 13 | **16** | 13 | **29,980** | 34,593 |
|  | **$1,202** | $1,124 | **9,150** | 9,197 | **$56** | $51 | **33,171** | 37,845 |
| Nine Months |  |  |  |  |  |  |  |  |
| Retail | **$2,630** | $2,514 | **19,270** | 19,075 | **$367** | $327 | **31,490** | 33,188 |
| Sales for resale: |  |  |  |  |  |  |  |  |
| Wholesale | **115** | 148 | **1,607** | 2,055 | **N/A** | N/A | **N/A** | N/A |
| Bulk power and other | **170** | 133 | **4,066** | 4,050 | **N/A** | N/A | **N/A** | N/A |
| Transportation/Other | **36** | 33 | **40** | 41 | **41** | 39 | **92,749** | 92,758 |
|  | **$2,951** | $2,828 | **24,983** | 25,221 | **$408** | $366 | **124,239** | 125,946 |

33

| IPL Three Months | Electric Revenues 2026 | 2025 | MWhs Sold 2026 | 2025 | Gas Revenues 2026 | 2025 | Dths Sold 2026 | 2025 |
| --- | ---: | ---: | ---: | ---: | ---: | ---: | ---: | ---: |
| Retail | **$606** | $574 | **3,860** | 3,812 | **$23** | $20 | **1,430** | 1,489 |
| Sales for resale: |  |  |  |  |  |  |  |  |
| Wholesale | **3** | 11 | **3** | 135 | **N/A** | N/A | **N/A** | N/A |
| Bulk power and other | **15** | 17 | **477** | 503 | **N/A** | N/A | **N/A** | N/A |
| Transportation/Other | **7** | 6 | **8** | 7 | **9** | 7 | **10,099** | 10,309 |
|  | **$631** | $608 | **4,348** | 4,457 | **$32** | $27 | **11,529** | 11,798 |
| Nine Months |  |  |  |  |  |  |  |  |
| Retail | **$1,452** | $1,377 | **10,529** | 10,537 | **$175** | $162 | **14,871** | 15,928 |
| Sales for resale: |  |  |  |  |  |  |  |  |
| Wholesale | **3** | 39 | **8** | 478 | **N/A** | N/A | **N/A** | N/A |
| Bulk power and other | **26** | 19 | **1,469** | 1,199 | **N/A** | N/A | **N/A** | N/A |
| Transportation/Other | **18** | 20 | **23** | 23 | **22** | 23 | **32,289** | 32,675 |
|  | **$1,499** | $1,455 | **12,029** | 12,237 | **$197** | $185 | **47,160** | 48,603 |

| WPL Three Months | Electric Revenues 2026 | 2025 | MWhs Sold 2026 | 2025 | Gas Revenues 2026 | 2025 | Dths Sold 2026 | 2025 |
| --- | ---: | ---: | ---: | ---: | ---: | ---: | ---: | ---: |
| Retail | **$449** | $422 | **3,286** | 3,162 | **$17** | $18 | **1,761** | 1,763 |
| Sales for resale: |  |  |  |  |  |  |  |  |
| Wholesale | **42** | 40 | **596** | 578 | **N/A** | N/A | **N/A** | N/A |
| Bulk power and other | **72** | 47 | **914** | 994 | **N/A** | N/A | **N/A** | N/A |
| Transportation/Other | **8** | 7 | **6** | 6 | **7** | 6 | **19,881** | 24,284 |
|  | **$571** | $516 | **4,802** | 4,740 | **$24** | $24 | **21,642** | 26,047 |
| Nine Months |  |  |  |  |  |  |  |  |
| Retail | **$1,178** | $1,137 | **8,741** | 8,538 | **$192** | $165 | **16,619** | 17,260 |
| Sales for resale: |  |  |  |  |  |  |  |  |
| Wholesale | **112** | 109 | **1,599** | 1,577 | **N/A** | N/A | **N/A** | N/A |
| Bulk power and other | **144** | 114 | **2,597** | 2,851 | **N/A** | N/A | **N/A** | N/A |
| Transportation/Other | **18** | 13 | **17** | 18 | **19** | 16 | **60,460** | 60,083 |
|  | **$1,452** | $1,373 | **12,954** | 12,984 | **$211** | $181 | **77,079** | 77,343 |

**Sales Trends and Temperatures -** Alliant Energy’s retail electric sales volumes increased 2% and increased 1% for the three and nine months ended September 30, 2026, respectively, compared to the same periods in 2025, primarily due to higher sales to commercial and industrial customers at WPL and changes in temperatures, which increased sales volumes for the three-month period and decreased sales volumes for the nine-month period, compared to the same periods in 2025. Alliant Energy’s retail gas sales volumes decreased 2% and decreased 5% for the three and nine months ended September 30, 2026, respectively, compared to the same periods in 2025, primarily due to changes in temperatures and lower sales to industrial customers at IPL.

Estimated increases (decreases) to operating income from the impacts of temperatures for the three and nine months ended September 30 were as follows (in millions):

|  | Electric Three Months 2026 | 2025 | Change | Nine Months 2026 | 2025 | Change | Gas Three Months 2026 | 2025 | Change | Nine Months 2026 | 2025 | Change |
| --- | ---: | ---: | ---: | ---: | ---: | ---: | ---: | ---: | ---: | ---: | ---: | ---: |
| IPL | **$14** | $11 | $3 | **$5** | $12 | ($7) | **$—** | $— | $— | **($6)** | ($4) | ($2) |
| WPL | **6** | (1) | 7 | **(3)** | — | (3) | **—** | — | — | **(3)** | (1) | (2) |
| Total Alliant Energy | **$20** | $10 | $10 | **$2** | $12 | ($10) | **$—** | $— | $— | **($9)** | ($5) | ($4) |

**Electric Sales for Resale -** Alliant Energy’s and IPL’s wholesale sales volumes decreased for the three and nine months ended September 30, 2026, respectively, compared to the same periods in 2025, primarily due to the expiration of IPL’s wholesale power agreement with Southern Minnesota Energy Cooperative in 2025.

Bulk power and other volume changes were due to changes in sales in the wholesale energy markets operated by MISO. These changes are impacted by several factors, including the availability and dispatch of Alliant Energy’s EGUs and electricity demand within these wholesale energy markets. Changes in bulk power and other revenues were largely offset by changes in fuel-related costs, and therefore did not have a significant impact on operating income.

**Gas Transportation/Other -** Gas transportation/other sales volume changes were largely due to changes in the gas volumes supplied to Alliant Energy’s natural gas-fired EGUs caused by the availability and dispatch of such EGUs.

**Electric Utility Revenue Variances -** The following items contributed to increased (decreased) electric utility revenues for the three and nine months ended September 30, 2026 compared to the same periods in 2025 (in millions):

|  | Three Months Alliant Energy | IPL | WPL | Nine Months Alliant Energy | IPL | WPL |
| --- | ---: | ---: | ---: | ---: | ---: | ---: |
| Higher revenue requirements (a) | $35 | $— | $35 | $88 | $— | $88 |
| Higher revenues at IPL due to credits on customers’ bills through the tax benefit rider in 2025 (partially offset by changes in wholesale revenues and income taxes) | 19 | 19 | — | 53 | 53 | — |
| Higher (lower) sales for resale bulk power and other revenues (b) | 23 | (2) | 25 | 37 | 7 | 30 |
| Higher revenues at IPL related to changes in recovery amounts for electric transmission service costs through the transmission cost rider (mostly offset in electric transmission service expense) (Refer to Electric Transmission Service Expense Variances below) | 13 | 13 | — | 23 | 23 | — |
| Higher revenues at IPL related to changes in recovery amounts for energy efficiency costs through the energy efficiency rider (mostly offset by changes in energy efficiency expense) | — | — | — | 9 | 9 | — |
| Lower revenues primarily due to changes in retail electric fuel-related costs (Refer to Electric Production Fuel and Purchased Power Expenses Variances below) (a) | (25) | (13) | (12) | (40) | (15) | (25) |
| Changes in WPL refunds/collections of previous over-/under-collection of retail electric fuel-related costs (offset in electric production fuel and purchased power expenses) | (15) | — | (15) | (39) | — | (39) |
| Lower wholesale revenues at IPL primarily due to lower sales from the expiration of IPL’s wholesale power agreement with Southern Minnesota Energy Cooperative in 2025 | (8) | (8) | — | (36) | (36) | — |
| Lower revenues at IPL due to credits on customers’ bills related to production tax credits through its fuel-related cost recovery mechanism (offset by changes in income taxes) | (4) | (4) | — | (13) | (13) | — |
| Estimated changes in sales volumes caused by temperatures | 10 | 3 | 7 | (10) | (7) | (3) |
| Other (primarily due to higher temperature-normalized retail sales) | 30 | 15 | 15 | 51 | 23 | 28 |
|  | $78 | $23 | $55 | $123 | $44 | $79 |

(a) In December 2025, the PSCW issued an order authorizing an annual base rate increase of $69 million for WPL’s retail electric customers, covering the 2026 forward-looking Test Period, which reflects revenue requirement impacts of increasing electric rate base, including wind refurbishment projects, energy storage, existing natural gas-fired EGU improvements and electric distribution investments and lower forecasted fuel-related expenses.

(b) Sales for resale bulk power and other revenues increased for the three and nine months ended September 30, 2026 compared to the same periods in 2025, primarily due to higher prices for electricity and capacity sold by WPL to MISO wholesale energy markets. These changes were largely offset by changes in fuel-related costs.

**Gas Utility Revenue Variances -** The following items contributed to increased (decreased) gas utility revenues for the three and nine months ended September 30, 2026 compared to the same periods in 2025 (in millions):

|  | Three Months Alliant Energy | IPL | WPL | Nine Months Alliant Energy | IPL | WPL |
| --- | ---: | ---: | ---: | ---: | ---: | ---: |
| Higher (lower) revenues due to changes in gas costs (Refer to Cost of Gas Sold Expense Variances below) | $1 | $2 | ($1) | $43 | $17 | $26 |
| Higher revenue requirements (a) | 1 | — | 1 | 4 | — | 4 |
| Estimated changes in sales volumes caused by temperatures | — | — | — | (4) | (2) | (2) |
| Lower revenues at IPL related to changes in recovery amounts for energy efficiency costs through the energy efficiency rider (mostly offset by changes in energy efficiency expense) | — | — | — | (3) | (3) | — |
| Other | 3 | 3 | — | 2 | — | 2 |
|  | $5 | $5 | $— | $42 | $12 | $30 |

(a) In December 2025, the PSCW issued an order authorizing an annual base rate increase of $7 million for WPL’s retail gas customers, covering the 2026 forward-looking Test Period, which reflects revenue requirement impacts of increasing gas rate base.

**Electric Production Fuel and Purchased Power Expenses Variances -** The following items contributed to (increased) decreased electric production fuel and purchased power expenses for the three and nine months ended September 30, 2026 compared to the same periods in 2025 (in millions):

|  | Three Months Alliant Energy | IPL | WPL | Nine Months Alliant Energy | IPL | WPL |
| --- | ---: | ---: | ---: | ---: | ---: | ---: |
| Changes in WPL refunds/collections of previous over-/under-collection of retail electric fuel-related costs (offset in electric utility revenue) | $15 | $— | $15 | $39 | $— | $39 |
| (Higher) lower purchased power expense (a) | (6) | (7) | 1 | 22 | 22 | — |
| Changes in regulatory recovery of retail electric fuel-related costs | 9 | 16 | (7) | 5 | (9) | 14 |
| (Higher) lower electric production fuel costs (b) | 5 | 7 | (2) | (17) | 1 | (18) |
| Other | (6) | 1 | (7) | (7) | 1 | (8) |
|  | $17 | $17 | $— | $42 | $15 | $27 |

(a) Purchased power expense decreased for the nine months ended September 30, 2026 compared to the same period in 2025, primarily due to lower prices for electricity purchased at IPL.

(b) Electric production fuel costs increased for the nine months ended September 30, 2026 compared to the same period in 2025, primarily due to higher natural gas prices and higher natural gas volumes at WPL due to higher dispatch of natural gas-fired EGUs, partially offset by lower coal volumes at WPL due to lower dispatch of coal-fired EGUs.

**Electric Transmission Service Expense Variances -** The following items contributed to (increased) decreased electric transmission service expense for the three and nine months ended September 30, 2026 compared to the same periods in 2025 (in millions):

|  | Three Months Alliant Energy | IPL | WPL | Nine Months Alliant Energy | IPL | WPL |
| --- | ---: | ---: | ---: | ---: | ---: | ---: |
| Changes in regulatory recovery for the difference between actual electric transmission service costs and those costs used to determine rates | $11 | $11 | $— | $27 | $27 | $— |
| Other (primarily due to changes in transmission service costs provided by third parties) | (21) | (15) | (6) | (43) | (25) | (18) |
|  | ($10) | ($4) | ($6) | ($16) | $2 | ($18) |

**Cost of Gas Sold Expense Variances -** The following items contributed to (increased) decreased cost of gas sold expense for the three and nine months ended September 30, 2026 compared to the same periods in 2025 (in millions):

|  | Three Months Alliant Energy | IPL | WPL | Nine Months Alliant Energy | IPL | WPL |
| --- | ---: | ---: | ---: | ---: | ---: | ---: |
| Changes in retail gas volumes and natural gas prices | ($2) | ($1) | ($1) | ($47) | ($23) | ($24) |
| Changes in the regulatory recovery of gas costs | — | (2) | 2 | 3 | 5 | (2) |
| Other | 1 | — | 1 | 1 | 1 | — |
|  | ($1) | ($3) | $2 | ($43) | ($17) | ($26) |

36

**Other Operation and Maintenance Expenses Variances -** The following items contributed to (increased) decreased other operation and maintenance expenses for the three and nine months ended September 30, 2026 compared to the same periods in 2025 (in millions):

|  | Three Months Alliant Energy | IPL | WPL | Nine Months Alliant Energy | IPL | WPL |
| --- | ---: | ---: | ---: | ---: | ---: | ---: |
| Higher incentive compensation expense | ($17) | ($9) | ($8) | ($37) | ($20) | ($17) |
| Higher generation and energy delivery expenses | (6) | — | (6) | (23) | (7) | (16) |
| Higher energy efficiency expense at IPL (mostly offset by higher revenues) | — | — | — | (9) | (9) | — |
| Other | (1) | 5 | (5) | (19) | 2 | (18) |
|  | ($24) | ($4) | ($19) | ($88) | ($34) | ($51) |

**Other Future Considerations** - In addition to items discussed in this report, the following key items could impact Alliant Energy’s, IPL’s and WPL’s future financial condition or results of operations:

- **Financing Plans -**
- Common Stock - For the remainder of 2026, Alliant Energy currently expects to physically settle up to $650 million of outstanding forward sale agreements in aggregate under the 2025 and/or 2026 at-the-market offering programs (ATM programs). From 2027 through 2030, Alliant Energy currently expects to issue up to $2.7 billion of common stock in aggregate through the ATM programs, its Shareowner Direct Plan (approximately $25 million in common stock annually) and additional future equity offerings. Refer to Note 5 for further details of common stock issuances and settlements under the 2025 and 2026 ATM programs.
- Long-term Debt - For the remainder of 2026, IPL and WPL currently expect to issue up to $200 million and $300 million of long-term debt, respectively, and in 2027, up to $1.3 billion and $500 million of long-term debt, respectively. Future IPL and WPL long-term debt issuances may include funding through the DOE Loan Guarantee Program. Refer to Liquidity and Capital Resources for further details of the program. In 2027, AEF and/or Alliant Energy at the parent company level expect to issue up to $1 billion of long-term debt in aggregate. AEF and WPL have $375 million and $300 million, respectively, of long-term debt maturing in 2027.
- **Common Stock Dividends** - Alliant Energy announced a 5% increase in its targeted 2027 annual common stock dividend to $2.25 per share, which is equivalent to a quarterly rate of $0.5625 per share, beginning with the February 2027 dividend payment. The timing and amount of future dividends is subject to approval of quarterly dividend declarations from Alliant Energy’s Board of Directors, and is dependent upon earnings expectations, capital requirements, and general financial business conditions, among other factors.
- **Cash Flows from Operating Activities** - Alliant Energy, IPL and WPL currently expect an increase in future cash flows from operating activities resulting from the transfer of future renewable tax credits to other corporate taxpayers. Refer to Note 8 for renewable tax credits transferred in October 2026. In addition, Alliant Energy, IPL and WPL currently expect an increase in future cash flows from operating activities resulting from higher retail electric sales in 2027 driven by large load growth customers. Alliant Energy and WPL also expect an increase in future cash flows from operating activities resulting from higher earnings on WPL’s increasing rate base.
- **Higher Earnings on Increasing Rate Base** - Alliant Energy and WPL currently expect electric and gas utility revenues to increase in 2027 compared to 2026, primarily due to impacts from increasing revenue requirements related to investments in the utility business. IPL currently expects an increase in its effective income tax rate in 2027 compared to 2026 due to higher income before income taxes, partially offset by greater utilization of investment tax credits. Investment tax credits resulting from IPL energy storage projects placed in service and/or expected to be placed in service in 2026 and 2027 may be utilized to offset any revenue deficiency on an annual basis up to the earnings sharing mechanism threshold included in IPL’s retail electric rate review settlement agreement.
- **Sales Trends** - Alliant Energy, IPL and WPL currently expect an increase in retail electric sales in 2027 compared to 2026 driven by large load growth customers, including data center customers and other economic development activities. Refer to “Growing Customer Demand” for further discussion.
- **Depreciation and Amortization Expense** - Alliant Energy, IPL and WPL currently expect an increase in depreciation and amortization expense in 2027 compared to 2026 due to capital projects placed in service in 2026 and 2027.
- **Interest Expense** - Alliant Energy, IPL and WPL currently expect an increase in interest expense in 2027 compared to 2026 due to financings completed in 2026 and planned in 2027.
- **Equity Income from Unconsolidated Investments** - Alliant Energy’s equity earnings from certain corporate venture fund investments have increased during 2026 due to increased valuations of certain underlying investments within the venture funds. Refer to Note 4 for further details.
- **Allowance for Funds Used During Construction** - Alliant Energy, IPL and WPL currently expect an increase in allowance for funds used during construction in 2027 compared to 2026 largely due to changes in construction work in progress balances related to construction activity on capital projects.

### LIQUIDITY AND CAPITAL RESOURCES

The liquidity and capital resources summary included in the 2025 Form 10-K has not changed materially, except as described below.

**Liquidity Position -** At September 30, 2026, Alliant Energy had $26 million of cash and cash equivalents, $596 million ($139 million at the parent company, $300 million at IPL and $157 million at WPL) of available capacity under the single revolving credit facility and no available capacity at IPL under its sales of accounts receivable program at the current limit on cash proceeds.

**Capital Structure -** The following table shows financial capital structures as of September 30, 2026, as well as an adjusted capitalization structure that Alliant Energy believes is consistent with how a majority of the rating agencies currently view its junior subordinated notes (in millions):

|  | Alliant Energy Actual | Adjusted (a) | IPL Actual | WPL Actual |
| --- | ---: | ---: | ---: | ---: |
| Common equity | $7,808 | $8,171 | $5,284 | $4,662 |
| Long-term debt (including current maturities) | 11,459 | 11,096 | 5,179 | 3,672 |
| Short-term debt | 1,104 | 1,104 | — | 143 |
| Total capitalization | $20,371 | $20,371 | $10,463 | $8,477 |
| Total debt | $12,563 | $12,200 | $5,179 | $3,815 |
| Ratio of debt to total capitalization | 62% | 60% | 49% | 45% |

(a) The long-term debt component of Alliant Energy’s financial capital structure includes junior subordinated notes classified as “Long-term debt, net” on Alliant Energy’s balance sheet. The adjusted presentation attributes 50% of the junior subordinated notes to common equity and 50% to long-term debt, to align with the debt-to-capital ratio used by the majority of rating agencies. The non-GAAP adjusted presentation reflecting this treatment is useful and relevant to investors in understanding how management and the rating agencies evaluate Alliant Energy’s capital structure.

**Cash Flows -** Selected information from the cash flows statements was as follows (in millions):

|  | Alliant Energy 2026 | 2025 | IPL 2026 | 2025 | WPL 2026 | 2025 |
| --- | ---: | ---: | ---: | ---: | ---: | ---: |
| Cash, cash equivalents and restricted cash, January 1 | **$556** | $81 | **$7** | $29 | **$37** | $51 |
| Cash flows from (used for): |  |  |  |  |  |  |
| Operating activities | **909** | 900 | **249** | 289 | **612** | 573 |
| Investing activities | **(1,538)** | (1,605) | **(686)** | (660) | **(714)** | (530) |
| Financing activities | **99** | 1,127 | **442** | 551 | **78** | (83) |
| Net increase (decrease) | **(530)** | 422 | **5** | 180 | **(24)** | (40) |
| Cash, cash equivalents and restricted cash, September 30 | **$26** | $503 | **$12** | $209 | **$13** | $11 |

**Operating Activities -** The following items contributed to increased (decreased) operating activity cash flows for the nine months ended September 30, 2026 compared to the same period in 2025 (in millions):

|  | Alliant Energy | IPL | WPL |
| --- | ---: | ---: | ---: |
| Higher collections from WPL’s retail electric and gas base rate increases | $92 | $— | $92 |
| Higher collections from IPL’s retail customers due to credits on customers’ bills related to the tax benefit rider in 2025 | 53 | 53 | — |
| Timing of WPL’s fuel-related cost recoveries from retail electric customers | (53) | — | (53) |
| Changes in interest payments | (40) | (12) | (10) |
| Lower wholesale revenues at IPL primarily due to lower sales from the expiration of IPL’s wholesale power agreement with Southern Minnesota Energy Cooperative in 2025 | (36) | (36) | — |
| Changes in levels of materials and supplies | (26) | (12) | (14) |
| Other (primarily due to other changes in working capital) | 19 | (33) | 24 |
|  | $9 | ($40) | $39 |

38

**Investing Activities -** The following items contributed to increased (decreased) investing activity cash flows for the nine months ended September 30, 2026 compared to the same period in 2025 (in millions):

|  | Alliant Energy | IPL | WPL |
| --- | ---: | ---: | ---: |
| Purchases of short-term investments in 2025 | $250 | $— | $— |
| Lower (higher) utility construction and acquisition expenditures (a)(b) | (156) | 8 | (221) |
| Other (b)(c) | (27) | (34) | 37 |
|  | $67 | ($26) | ($184) |

(a) Largely due to higher expenditures for IPL’s gas generation and WPL’s refurbishment of existing wind farms, partially offset by lower expenditures for IPL’s energy storage.

(b) Refer to Note 14 for details of the transfer of gas generation assets from WPL to IPL.

(c) Includes higher cash payments related to cost of removal obligations at IPL and WPL.

Construction and Acquisition Expenditures - Construction and acquisition expenditures and financing plans are reviewed, approved and updated as part of the strategic planning process. Changes may result from a number of reasons, including changes in expected load growth, regulatory requirements, changing legislation, not obtaining favorable and acceptable regulatory approval on certain projects, changing costs of projects due to market conditions and the impact of tariffs, improvements in technology, and improvements to ensure resiliency and reliability of the electric and gas distribution systems. Alliant Energy, IPL and WPL have not yet entered into contractual commitments relating to the majority of their anticipated future construction and acquisition expenditures. As a result, they have some discretion with regard to the level and timing of these expenditures. Construction and acquisition expenditures for 2026 through 2030 are currently anticipated as follows (in millions), which are focused on adding renewable generation and energy storage projects, dispatchable thermal generation and Liquified Natural Gas (LNG) projects to meet growing customer demand for electricity and natural gas, including expected future data center growth from currently executed electric service agreements, and strengthening the resiliency and reliability of the electric and gas distribution systems. Alliant Energy, IPL and WPL are currently evaluating the impacts of tariffs, recently enacted legislation and additional potential large load growth customers on their resource plans, and will update their anticipated construction and acquisition expenditures as needed in the future. Cost estimates represent Alliant Energy’s, IPL’s and WPL’s portion of construction expenditures and exclude allowance for funds used during construction and capitalized interest, if applicable. Refer to “Customer Investments” for further discussion of certain key utility business projects impacting construction and acquisition plans, and the related regulatory filings.

| Generation: | Alliant Energy 2026 | 2027 | 2028 | 2029 | 2030 | IPL 2026 | 2027 | 2028 | 2029 | 2030 | WPL 2026 | 2027 | 2028 | 2029 | 2030 |
| --- | ---: | ---: | ---: | ---: | ---: | ---: | ---: | ---: | ---: | ---: | ---: | ---: | ---: | ---: | ---: |
| Renewables and energy storage projects | $695 | $1,250 | $1,890 | $1,650 | $335 | $365 | $1,055 | $1,240 | $1,020 | $230 | $315 | $265 | $650 | $630 | $105 |
| Thermal generation & LNG | 1,250 | 2,090 | 1,855 | 1,655 | 1,205 | 830 | 1,630 | 1,535 | 1,485 | 1,065 | 385 | 460 | 320 | 170 | 140 |
| Distribution: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| Electric systems | 525 | 540 | 525 | 530 | 660 | 270 | 240 | 230 | 225 | 320 | 255 | 300 | 295 | 305 | 340 |
| Gas systems | 135 | 150 | 155 | 160 | 165 | 70 | 85 | 90 | 90 | 90 | 65 | 65 | 65 | 70 | 75 |
| Other | 255 | 275 | 310 | 290 | 245 | 55 | 50 | 40 | 65 | 70 | 45 | 35 | 40 | 55 | 40 |
|  | $2,860 | $4,305 | $4,735 | $4,285 | $2,610 | $1,590 | $3,060 | $3,135 | $2,885 | $1,775 | $1,065 | $1,125 | $1,370 | $1,230 | $700 |

**Financing Activities -** The following items contributed to increased (decreased) financing activity cash flows for the nine months ended September 30, 2026 compared to the same period in 2025 (in millions):

|  | Alliant Energy | IPL | WPL |
| --- | ---: | ---: | ---: |
| Lower net proceeds from issuance of long-term debt | ($1,678) | ($392) | $— |
| (Higher) lower payments to retire long-term debt | (775) | 300 | — |
| Changes in common stock dividends | (22) | 150 | (1) |
| Net changes in the amount of commercial paper outstanding | 982 | (38) | 134 |
| Higher proceeds from issuance of other short-term borrowings | 400 | — | — |
| Higher net proceeds from common stock issuances | 57 | — | — |
| Higher (lower) capital contributions from IPL’s and WPL’s parent company, Alliant Energy | — | (135) | 20 |
| Other | 8 | 6 | 8 |
|  | ($1,028) | ($109) | $161 |

Common Stock Issuances and Common Stock Dividends - Refer to Note 5 for discussion of common stock issuances by Alliant Energy in 2026 and Alliant Energy’s at-the-market offering programs. Refer to “Results of Operations” for discussion of expected future issuances of common stock for the remainder of 2026 through 2030 and common stock dividends in 2027.

Short-term Debt - Refer to Note 6(a) for discussion of Alliant Energy’s term loan credit agreement entered into in 2026.

Long-term Debt - Refer to Note 6(b) for discussion of issuances and/or retirements of long-term debt by Alliant Energy, AEF and IPL in 2026. Refer to “Results of Operations” for discussion of expected future issuances and retirements of long-term debt by the end of 2027.

U.S. Department of Energy (DOE) Loan Guarantee Borrowings - In October 2026, IPL and WPL each entered into a loan guarantee agreement with the DOE. Under the agreements, the DOE may guarantee borrowings of up to $3.5 billion for IPL and up to $1.6 billion for WPL, subject to satisfaction of applicable conditions and requirements. The guaranteed financing is intended to support eligible energy infrastructure projects and could provide lower-cost financing for the benefit of IPL’s and WPL’s customers. No amounts have been borrowed under the loan guarantee agreements.

### Impact of Credit Ratings on Liquidity and Collateral Obligations -

**Ratings Triggers -** In March 2026, Standard & Poor’s Ratings Services changed certain IPL credit ratings, which are not expected to have a material impact on Alliant Energy’s and IPL’s liquidity or collateral obligations. Alliant Energy’s, IPL’s and WPL’s current credit ratings and outlooks are as follows:

|  |  |  |
| --- | --- | --- |
|  |  | Standard & Poor’s Ratings Services |
| Alliant Energy: | Corporate/issuer | BBB+ |
|  | Commercial paper | A-2 |
|  | Senior unsecured long-term debt | BBB |
|  | Outlook | Stable |
| IPL: | Corporate/issuer | A- |
|  | Commercial paper | A-2 |
|  | Senior unsecured long-term debt | A- |
|  | Outlook | Stable |
| WPL: | Corporate/issuer | A- |
|  | Commercial paper | A-2 |
|  | Senior unsecured long-term debt | A- |
|  | Outlook | Stable |

**Off-Balance Sheet Arrangements and Certain Financial Commitments -** A summary of Alliant Energy’s and IPL’s off-balance sheet arrangements and Alliant Energy’s, IPL’s and WPL’s contractual obligations is included in the 2025 Form 10-K and has not changed materially from the items reported in the 2025 Form 10-K, except for the items described in Notes 3, 6 and 12.

## Market risk

As filed, 126 characters.

Quantitative and Qualitative Disclosures About Market Risk are reported in the 2025 Form 10-K and have not changed materially.

## Controls and procedures

As filed, 1,044 characters.

Alliant Energy’s, IPL’s and WPL’s management evaluated, with the participation of each of Alliant Energy’s, IPL’s and WPL’s Chief Executive Officer, Chief Financial Officer and Disclosure Committee, the effectiveness of the design and operation of Alliant Energy’s, IPL’s and WPL’s disclosure controls and procedures (as defined in Rule 13a-15(e) of the Securities Exchange Act of 1934, as amended) as of September 30, 2026 pursuant to the requirements of the Securities Exchange Act of 1934, as amended. Based on their evaluation, the Chief Executive Officer and the Chief Financial Officer concluded that Alliant Energy’s, IPL’s and WPL’s disclosure controls and procedures were effective as of the quarter ended September 30, 2026.

There was no change in Alliant Energy’s, IPL’s and WPL’s internal control over financial reporting that occurred during the quarter ended September 30, 2026 that has materially affected, or is reasonably likely to materially affect, Alliant Energy’s, IPL’s or WPL’s internal control over financial reporting.

Filed Oct 30, 2026.
Source: SEC EDGAR, the filing index for accession 0000352541-26-000047. Last ingested by Listed: Nov 6, 2026, 14:16 ET. No prices; not investment advice.