Item 2. MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

83K characters. Original on sec.gov · Markdown

Item 2. MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

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 2024 Form 10-K. Unless otherwise noted, all “per share” references in MDA refer to earnings per diluted share.

2025 HIGHLIGHTS

Key highlights since the filing of the 2024 Form 10-K include the following:

Customer Investments:

  • Over the next six years, Alliant Energy currently plans to develop and/or acquire new generation investments to add flexibility with evolving load growth, including approximately 2,000 MW of natural gas resources, approximately 1,300 MW of new energy storage, approximately 1,100 MW of new renewable generation, improvements of approximately 530 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 seasonal 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 2025 through 2029 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 February 2025, WPL filed a certificate of authority (CA) application with the PSCW for approval to construct a 2 billion cubic feet, or 25 million gallon, liquified natural gas facility in Rock County, Wisconsin. A decision from the PSCW is currently expected in the second quarter of 2026.

  • In April 2025, the PSCW issued an order authorizing WPL to construct, own and operate a 17.5 MW natural gas-fired EGU using Reciprocating Internal Combustion Engine (RICE) technology, at the site of its Riverside Energy Center.

  • In April 2025, WPL filed a CA application with the PSCW for approval to construct, own and operate the Bent Tree North EGU, an approximate 153 MW wind farm. A decision from the PSCW is currently expected in the second quarter of 2026.

28

Table of Contents

  • In May 2025, the PSCW issued an order authorizing WPL to refurbish the Bent Tree wind farm.

  • In June 2025, the IUC issued an order authorizing IPL to construct, own and operate the Cedar River Generating Station, a 94 MW natural gas-fired EGU using RICE technology, at the site of its Prairie Creek Generating Station.

  • In June 2025, the PSCW issued an order authorizing WPL to construct, own and operate an approximately 20 MW compressed carbon dioxide-based long-duration energy storage system at the site of its Columbia Energy Center.

  • In July 2025, IPL filed for advance rate-making principles with the IUC for up to 1,000 MW of new wind generation in Iowa. The advance rate-making principles filing included requests for a fixed cost cap of $3,020/kilowatt, including allowance for funds used during construction and transmission upgrade costs among other costs, and a return on common equity of 11.25%. A decision from the IUC is currently expected in the first quarter of 2026.

  • In July 2025, the IUC issued an order authorizing IPL to construct, own and operate up to 150 MW of energy storage at the site of its retired Lansing Generating Station.

  • In July 2025, WPL completed construction of approximately 100 MW of energy storage at the site of its Grant County solar facility.

  • In August 2025, the IUC issued an order authorizing IPL to construct, own and operate up to 75 MW of energy storage at the site of its Golden Plains wind farm.

  • In August 2025, IPL filed a certificate of public convenience, use and necessity (GCU Certificate) application with the IUC for approval to construct, own and operate an approximate 720 MW simple-cycle natural gas-fired EGU at the site of its Marshalltown Generating Station, known as the Bobcat Energy Center. A decision from the IUC is currently expected in the first quarter of 2026.

  • In September 2025, the IUC issued an order authorizing IPL to construct, own and operate up to 75 MW of energy storage at the site of its Whispering Willow - North wind farm.

  • In October 2025, WPL completed construction of approximately 75 MW of energy storage at the site of its Wood County solar facility.

  • In November 2025, IPL filed a GCU Certificate application with the IUC for approval to construct, own and operate a 94 MW natural gas-fired EGU using RICE technology at the site of its Burlington Generating Station. A decision from the IUC is currently expected in the first quarter of 2026.

Rate Matters:

  • In September 2025, WPL filed a unanimous settlement agreement with the PSCW for the 2026/2027 forward-looking Test Period. In November 2025, the PSCW issued an oral decision approving the settlement agreement. A written order from the PSCW is currently expected by the end of 2025. The settlement agreement reflects the following:

  • Annual incremental rate increases for its retail electric customers of $79 million and $73 million in 2026 (effective January 1, 2026) and 2027 (effective January 1, 2027), respectively, and an average retail electric rate base of $6,234 million and $6,549 million in 2026 and 2027, respectively.

  • Annual incremental rate increases for its retail gas customers of $7 million and $5 million in 2026 (effective January 1, 2026) and 2027 (effective January 1, 2027), respectively, and an average retail gas rate base of $558 million and $593 million in 2026 and 2027, respectively.

  • Return on common equity of 9.8% and common equity component of its regulatory capital structure of 54.5%.

  • Key drivers include revenue requirement impacts of increasing electric and gas rate base, including wind refurbishment projects, energy storage, existing natural gas-fired EGU improvements, solar generation costs incurred that exceed the construction cost estimates previously approved by the PSCW (refer to Note 3 for further discussion), and electric and gas distribution investments.

  • Extension, with certain modifications, of current earnings sharing mechanism through 2027, including deferral of a portion of earnings if the annual regulatory return on common equity exceeds 10.05% during the 2026/2027 Test Period (deferral of 50% of its excess earnings between 10.05% and 10.55%, and 100% of any excess earnings above 10.55%).

  • Allowance for funds used during construction applied to 100% of construction work in progress balances related to construction activity on capital projects requiring PSCW approval and are impacted by federal law changes.

  • IPL currently expects to file a subsequent proceeding with the IUC in the fourth quarter of 2025 for its October 2024 through September 2025 forward-looking Test Period retail electric and gas rate reviews, which will compare actual revenues and costs to those initially forecasted by IPL. IPL currently does not expect any rate adjustments from the subsequent proceeding.

Growing Customer Demand:

  • WPL has entered into electric service agreements with two new customers, who currently expect to build data centers in WPL’s service territory. The actual timing and amount of increases in WPL’s load are subject to various factors, including interconnections, siting approvals and actual customer demand, and any executed or future agreements with customers are not expected to result in immediate increases in load. IPL’s and WPL’s currently executed electric service agreements include aggregate, peak demands of approximately 3 gigawatts. The energy resources to serve this expected load are included in the construction and acquisition table in “Liquidity and Capital Resources.”

  • In May 2025 and October 2025, the IUC issued orders, with certain conditions, approving individual customer rates for data centers expected to be constructed in IPL’s service territory. In April 2025, WPL filed a request with the PSCW for approval of an individual customer rate for a data center expected to be constructed in its service territory. A decision from the PSCW is currently expected in the first quarter of 2026.

29

Table of Contents

Environmental Matters and Stewardship:

  • In March 2025, the EPA announced it expects to initiate a formal reconsideration of various environmental regulations and programs, including the Cross-State Air Pollution Rule and Effluent Limitation Guidelines. In June 2025, the EPA proposed to repeal emissions standards and guidelines issued under Clean Air Act Sections 111(b) and 111(d) for electric generating units. In July 2025, the EPA proposed to repeal its 2009 finding that GHG contributes to climate change, which gave it authority to regulate GHG under the Clean Air Act. In October 2025, the EPA proposed a rule to revise certain deadlines and other provisions of the 2024 Effluent Limitation Guidelines. The EPA also expects to expedite review of state programs to delegate implementation of the Coal Combustion Residuals Rule and reconsider compliance deadlines. Alliant Energy, IPL and WPL are currently unable to predict with certainty the future outcome or impact of these matters, including resolution of ongoing and potential litigation.

  • Alliant Energy’s current voluntary environmental stewardship goals include the following:

  • By 2030, reduce GHG emissions from its utility operations by 50% from 2005 levels, reduce its electric utility water supply by 75% from 2005 levels and electrify 100% of its owned light-duty fleet vehicles.

  • By 2040, eliminate all coal-fired EGUs from its generating fleet.

  • By 2050, aspire to achieve net-zero GHG emissions from its utility operations.

  • Alliant Energy’s aspirational GHG goal includes EPA reportable emissions based on applicable regulatory compliance requirements for carbon dioxide, methane and nitrous oxide from its owned fossil-fueled EGUs and distribution of natural gas. Alliant Energy’s voluntary environmental stewardship goals may be revised, or their achievement may be delayed, based on increasing customer energy needs, reliability and resource adequacy requirements, and tax policy changes, and the ability to achieve these goals is subject to various additional risk factors included in the 2024 Form 10-K. These goals are not meant to be considered guidance.

Legislative Matters:

  • In July 2025, the One Big Beautiful Bill Act was enacted, which modifies various clean energy tax credits under the Inflation Reduction Act of 2022, including production tax credits and investment tax credits. The most significant provisions of the new legislation for Alliant Energy, IPL and WPL relate to the accelerated phase out of clean energy tax credits for eligible projects for which construction begins more than 12 months after the date of enactment or for projects placed in service after 2027, and restricted access to clean energy tax credits for projects that begin construction after 2025 and receive impermissible amounts of construction support from entities with ties to certain foreign countries, including China. Additionally, in July 2025, the Presidential Administration directed the U.S. Department of the Treasury to strictly enforce the termination of clean energy tax credits, including issuing new and revised guidance in August 2025, to ensure that requirements concerning the beginning of construction are not circumvented. Refer to “2025 Highlights” for discussion of Alliant Energy’s, IPL’s and WPL’s current plans to develop and/or acquire new clean energy resources. Alliant Energy, IPL and WPL currently expect these clean energy projects would continue to be eligible for clean energy tax credits. If these clean energy projects do not begin construction within the anticipated timeframes or fail to meet other eligibility requirements, the amount of clean energy tax credits could be significantly reduced, which could adversely impact Alliant Energy’s, IPL’s and WPL’s financial condition and results of operations.

Financings and Common Stock Dividends:

  • Refer to “Results of Operations” for discussion of expected future issuances of common stock in 2026 through 2029 and common stock dividends in 2026, and expected future issuances and retirements of long-term debt by the end of 2026.

  • In April 2025, WPL submitted an application to the U.S. Army Corps of Engineers for up to $45 million in loans through the Corps Water Infrastructure Financing Program. If finalized, such loans would provide low interest financing for various proposed safety projects at WPL’s Kilbourn and Prairie du Sac hydro EGUs.

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 EPS attributable to Alliant Energy common shareowners for the three months ended September 30 were as follows (dollars in millions, except per share amounts):

20252024
Income (Loss)EPSIncome (Loss)EPS
Utilities and Corporate Services$292$1.13$308$1.20
ATC Holdings100.0490.04
Non-utility and Parent(21)(0.08)(22)(0.09)
Alliant Energy Consolidated$281$1.09$295$1.15

Alliant Energy’s Utilities and Corporate Services net income decreased by $16 million for the three-month period, primarily due to higher other operation and maintenance expenses, the timing of income tax expense, higher depreciation and financing expenses. These items were partially offset by higher revenue requirements from IPL’s and WPL’s capital investments.

30

Table of Contents

Alliant Energy’s Non-utility and Parent net income increased $1 million for the three-month period, primarily due to the timing of income taxes, partially offset by a state income tax apportionment charge.

Net Income Variances - The following items contributed to increased (decreased) net income for the three and nine months ended September 30, 2025 compared to the same periods in 2024 (in millions):

Three MonthsNine Months
Alliant EnergyIPLWPLAlliant EnergyIPLWPL
Revenues:
Changes in electric utility (Refer to details below)$125$85$40$249$137$112
Changes in gas utility (Refer to details below)2—2441034
Changes in other utility—1(1)12(1)
Changes in non-utility2——(1)——
Changes in total revenues1298641293149145
Operating expenses:
Changes in electric production fuel and purchased power (Refer to details below)(47)(27)(21)(71)(18)(53)
Changes in electric transmission service (Refer to details below)(1)—(2)(10)(5)(4)
Changes in cost of gas sold (Refer to details below)11—(28)(4)(24)
Asset valuation charge for IPL’s Lansing Generating Station in the second quarter of 2024 (Refer to Note 2 for details)———6060—
Changes in other operation and maintenance (Refer to details below)(30)(12)(12)(20)6(22)
Changes in depreciation and amortization (Higher primarily due to solar generation placed in service in 2024 and updated electric depreciation rates for IPL effective October 1, 2024)(16)(16)(1)(60)(52)(6)
Changes in taxes other than income taxes—(1)1(1)1(1)
Changes in total operating expenses(93)(55)(35)(130)(12)(110)
Changes in operating income3631616313735
Other income and deductions:
Changes in interest expense (Higher primarily due to financings completed in 2024 and 2025)(14)(10)(1)(43)(26)(5)
Changes in equity income from unconsolidated investments, net (Refer to Note 5 for details)4——(3)——
Changes in allowance for funds used during construction422734
Changes in Other—(1)(1)(1)2(5)
Changes in total other income and deductions(6)(9)—(40)(21)(6)
Changes in income before income taxes3022612311629
Changes in income taxes (Refer to Note 9 for details)(44)(47)35(14)22
Changes in net income($14)($25)$9$128$102$51
31

Table of Contents

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 EnergyElectricGas
RevenuesMWhs SoldRevenuesDths Sold
20252024202520242025202420252024
Three Months
Retail$996$8876,9746,697$38$383,2523,281
Sales for resale:
Wholesale5158713782N/AN/AN/AN/A
Bulk power and other64311,4971,363N/AN/AN/AN/A
Transportation/Other13231314131134,59330,239
$1,124$9999,1978,856$51$4937,84533,520
Nine Months
Retail$2,514$2,31219,07518,633$327$28933,18829,128
Sales for resale:
Wholesale1481472,0552,115N/AN/AN/AN/A
Bulk power and other133664,0504,120N/AN/AN/AN/A
Transportation/Other33544143393392,75893,248
$2,828$2,57925,22124,911$366$322125,946122,376
IPLElectricGas
RevenuesMWhs SoldRevenuesDths Sold
20252024202520242025202420252024
Three Months
Retail$574$4973,8123,647$20$211,4891,606
Sales for resale:
Wholesale1119135212N/AN/AN/AN/A
Bulk power and other17—503248N/AN/AN/AN/A
Transportation/Other67787610,30910,337
$608$5234,4574,115$27$2711,79811,943
Nine Months
Retail$1,377$1,25910,53710,302$162$15615,92814,491
Sales for resale:
Wholesale3945478568N/AN/AN/AN/A
Bulk power and other19(5)1,199777N/AN/AN/AN/A
Transportation/Other20192324231932,67531,621
$1,455$1,31812,23711,671$185$17548,60346,112
WPLElectricGas
RevenuesMWhs SoldRevenuesDths Sold
20252024202520242025202420252024
Three Months
Retail$422$3903,1623,050$18$171,7631,675
Sales for resale:
Wholesale4039578570N/AN/AN/AN/A
Bulk power and other47319941,115N/AN/AN/AN/A
Transportation/Other716666524,28419,902
$516$4764,7404,741$24$2226,04721,577
Nine Months
Retail$1,137$1,0538,5388,331$165$13317,26014,637
Sales for resale:
Wholesale1091021,5771,547N/AN/AN/AN/A
Bulk power and other114712,8513,343N/AN/AN/AN/A
Transportation/Other13351819161460,08361,627
$1,373$1,26112,98413,240$181$14777,34376,264
32

Table of Contents

Sales Trends and Temperatures - Alliant Energy’s retail electric sales volumes increased 4% and 2% for the three and nine months ended September 30, 2025, respectively, compared to the same periods in 2024, primarily due to changes in temperatures and higher sales to industrial customers. Alliant Energy’s retail gas sales volumes increased 14% for the nine months ended September 30, 2025, compared to the same period in 2024, primarily due to changes in temperatures.

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):

ElectricGas
Three MonthsNine MonthsThree MonthsNine Months
20252024Change20252024Change20252024Change20252024Change
IPL$11$1$10$12($7)$19$—($1)$1($4)($8)$4
WPL(1)—(1)—(11)11—(1)1(1)(7)6
Total Alliant Energy$10$1$9$12($18)$30$—($2)$2($5)($15)$10

Electric Sales for Resale - Bulk Power and Other - 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, 2025 compared to the same periods in 2024 (in millions):

Three MonthsNine Months
Alliant EnergyIPLWPLAlliant EnergyIPLWPL
Higher revenue requirements (a)(b)$118$100$18$319$271$48
Higher sales for resale bulk power and other revenues (c)331716672443
Estimated changes in sales volumes caused by temperatures910(1)301911
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)77—1414—
Higher (lower) revenues primarily due to changes in retail electric fuel-related costs (Refer to Electric Production Fuel and Purchased Power Expenses Variances below)2317610(1)11
Changes in WPL electric fuel-related costs, net of recoveries (d)1—17—7
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) (a)(27)(27)—(116)(116)—
Lower revenues at IPL due to credits on customers’ bills through the tax benefit rider in 2025 (partially offset by changes in income taxes) (a)(19)(19)—(53)(53)—
Lower revenues at IPL from discontinuation of renewable energy rider in 2024 (a)(15)(15)—(23)(23)—
Other(5)(5)—(6)2(8)
$125$85$40$249$137$112

(a)In September 2024, the IUC issued an order authorizing an annual base rate increase of $185 million for IPL’s retail electric customers, with customers receiving partially offsetting credits for the first 12 months through a tax benefit rider, for the October 2024 through September 2025 forward-looking Test Period. Rate changes were effective October 1, 2024, which reflect revenue requirement impacts of increasing electric rate base including investments in solar generation, updated depreciation rates, and certain incremental costs incurred resulting from the 2020 derecho windstorm. In addition, effective October 1, 2024, IPL’s renewable energy rider was discontinued, and certain production tax credits are credited to IPL’s retail electric customers through IPL’s fuel-related cost recovery mechanism. Credits on IPL’s customers’ bills have been and are expected to be offset by a reduction in income tax expense.

(b)In December 2023, the PSCW issued an order authorizing an annual base rate increase of $60 million for WPL’s retail electric customers, covering the 2025 forward-looking Test Period, which reflects revenue requirement impacts of increasing electric rate base including investments in solar generation and energy storage.

33

Table of Contents

(c)Sales for resale bulk power and other revenues increased primarily due to higher prices for electricity and capacity sold by IPL and WPL to MISO wholesale energy markets. These changes were largely offset by changes in fuel-related costs.

(d)WPL’s cost recovery mechanism for retail fuel-related expenses supports deferrals of amounts that fall outside an approved fuel monitoring range of forecasted fuel-related expenses determined by the PSCW each year. The difference between revenue collected and actual fuel-related expenses incurred within the fuel monitoring range increases or decreases Alliant Energy’s and WPL’s electric utility revenues. WPL estimates the increase (decrease) to electric utility revenues from amounts within the fuel monitoring range were approximately $1 million and $3 million for the three and nine months ended September 30, 2025, respectively, compared to $0 and ($4) million for the three and nine months ended September 30, 2024, respectively.

Gas Utility Revenue Variances - The following items contributed to increased (decreased) gas utility revenues for the three and nine months ended September 30, 2025 compared to the same periods in 2024 (in millions):

Three MonthsNine Months
Alliant EnergyIPLWPLAlliant EnergyIPLWPL
Higher (lower) revenues due to changes in gas costs (Refer to Cost of Gas Sold Expense Variances below)($1)($1)$—$28$4$24
Estimated changes in sales volumes caused by temperatures2111046
Higher revenue requirements (a)11—66—
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)———(6)(6)—
Other—(1)1624
$2$—$2$44$10$34

(a)In September 2024, the IUC issued an order authorizing an annual base rate increase of $10 million for IPL’s retail gas customers, for the October 2024 through September 2025 forward-looking Test Period. Rate changes were effective October 1, 2024, which reflect 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, 2025 compared to the same periods in 2024 (in millions):

Three MonthsNine Months
Alliant EnergyIPLWPLAlliant EnergyIPLWPL
Higher electric production fuel costs (a)($27)($20)($7)($55)($37)($18)
Lower (higher) purchased power expense (b)(3)2(5)(13)6(19)
Changes in regulatory recovery of retail electric fuel-related costs(17)(9)(8)(4)13(17)
Other——(1)1—1
($47)($27)($21)($71)($18)($53)

(a)Electric production fuel costs increased for the three and nine months ended September 30, 2025 compared to the same periods in 2024, primarily due to higher coal volumes due to higher dispatch of coal-fired EGUs and higher natural gas prices, partially offset by lower natural gas volumes due to lower dispatch of natural gas-fired EGUs.

(b)Purchased power expense increased for the three and nine months ended September 30, 2025 compared to the same periods in 2024, primarily due to higher prices for electricity purchased at WPL.

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, 2025 compared to the same periods in 2024 (in millions):

Three MonthsNine Months
Alliant EnergyIPLWPLAlliant EnergyIPLWPL
Changes in regulatory recovery for the difference between actual electric transmission service costs and those costs used to determine rates$4$2$2$11$3$8
Other (primarily due to changes in transmission service costs provided by third parties)(5)(2)(4)(21)(8)(12)
($1)$—($2)($10)($5)($4)
34

Table of Contents

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, 2025 compared to the same periods in 2024 (in millions):

Three MonthsNine Months
Alliant EnergyIPLWPLAlliant EnergyIPLWPL
Changes in retail gas volumes and natural gas prices($6)$1($7)($29)($6)($23)
Changes in the regulatory recovery of gas costs7—712(1)
$1$1$—($28)($4)($24)

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, 2025 compared to the same periods in 2024 (in millions):

Three MonthsNine Months
Alliant EnergyIPLWPLAlliant EnergyIPLWPL
Higher generation and energy delivery expenses($13)($6)($7)($11)$—($11)
Higher incentive compensation expense(5)(3)(2)(10)(5)(5)
Higher energy efficiency expense at IPL (mostly offset by higher revenues)(7)(7)—(7)(7)—
Development costs for new generation(6)(4)(2)(6)(4)(2)
ARO charge in the second quarter of 2024 for steam assets at IPL (Refer to Note 1(d) for details)———2020—
Other18(1)(6)2(4)
($30)($12)($12)($20)$6($22)

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** - Alliant Energy currently expects to issue up to $2.4 billion of common stock in aggregate from 2026 through 2029 through the distribution agreement that was executed in May 2025, its Shareholder Direct Plan (up to $25 million in common stock annually) and additional future equity offerings. For the remainder of 2025, WPL currently expects to issue up to $300 million of long-term debt. In 2026, IPL and WPL currently expect to issue up to $500 million and $300 million, respectively, of long-term debt, and AEF and/or Alliant Energy at the parent company level expect to issue up to $300 million of long-term debt in aggregate. AEF and Alliant Energy at the parent company level have $500 million and $575 million, respectively, of long-term debt maturing in 2026.

  • Common Stock Dividends** - Alliant Energy announced a 5% increase in its targeted 2026 annual common stock dividend to $2.14 per share, which is equivalent to a quarterly rate of $0.535 per share, beginning with the February 2026 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.

  • Higher Earnings on Increasing Rate Base** - Alliant Energy and WPL currently expect increases in electric utility and gas utility revenues in 2026 compared to 2025 due to impacts from increasing revenue requirements related to investments in the utility business (refer to “Rate Matters” for further discussion). Additionally, Alliant Energy and IPL currently expect electric utility revenues to increase in 2026 compared to 2025 due to the expiration of tax benefit rider credits in 2025. Furthermore, Alliant Energy, IPL and WPL currently expect a decrease in the effective income tax rate in 2026 compared to 2025 due to additional renewable tax credits from renewable generation and energy storage projects placed in service and/or expected to be placed in service in 2025 and 2026. A majority of the differences between actual renewable tax credits and renewable tax credits used to determine rates are recorded in regulatory assets or regulatory liabilities on the balance sheets until they are reflected in future billings to customers. Investment tax credits resulting from IPL energy storage projects placed in service and/or expected to be placed in service in 2025 and 2026 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 2026 compared to 2025 driven by expected load growth from new customers who currently expect to build data centers in IPL’s and WPL’s service territories. Refer to “Growing Customer Demand” for further discussion.

  • Other Operation and Maintenance Expenses** - Alliant Energy, IPL and WPL currently expect an increase in other operation and maintenance expenses in 2026 compared to 2025 largely due to higher generation maintenance and energy delivery expenses.

  • Depreciation and Amortization Expense** - Alliant Energy, IPL and WPL currently expect an increase in depreciation and amortization expense in 2026 compared to 2025 due to capital projects placed in service in 2025 and 2026.

  • Interest Expense** - Alliant Energy, IPL and WPL currently expect an increase in interest expense in 2026 compared to 2025 due to financings completed in 2025 and planned in 2026 as discussed above.

  • Allowance for Funds Used During Construction** - Alliant Energy, IPL and WPL currently expect an increase in allowance for funds used during construction in 2026 compared to 2025 largely due to changes in construction work in progress balances related to construction activity on capital projects.

35

Table of Contents

LIQUIDITY AND CAPITAL RESOURCES

The liquidity and capital resources summary included in the 2024 Form 10-K has not changed materially, except as described below.

Liquidity Position - At September 30, 2025, Alliant Energy had $503 million of cash and cash equivalents, $250 million of short-term investments, $1,108 million ($550 million at the parent company, $350 million at IPL and $208 million at WPL) of available capacity under the single revolving credit facility and $4 million of available capacity at IPL under its sales of accounts receivable program.

Capital Structure - Financial capital structures at September 30, 2025 were as follows (Long-term Debt (including current maturities) (LD); Short-term Debt (SD); Common Equity (CE)):

636637638

(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 (refer to Note 7 for additional information). 50% of the carrying amount of junior subordinated notes is excluded from the debt component of Alliant Energy’s debt-to-capital ratio used by the majority of rating agencies. Alliant Energy’s financial capital structure adjusted for the reclassification of 50% of the carrying amount of junior subordinated notes from long-term debt to common equity at September 30, 2025 was as follows: LD: 59%, CE: 40% and SD: 1%. 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 EnergyIPLWPL
202520242025202420252024
Cash, cash equivalents and restricted cash, January 1$81$63$29$53$51$7
Cash flows from (used for):
Operating activities900913289231573651
Investing activities(1,605)(940)(660)(332)(530)(464)
Financing activities1,127794551804(83)(125)
Net increase (decrease)422767180703(40)62
Cash, cash equivalents and restricted cash, September 30$503$830$209$756$11$69
36

Table of Contents

Operating Activities - The following items contributed to increased (decreased) operating activity cash flows for the nine months ended September 30, 2025 compared to the same period in 2024 (in millions):

Alliant EnergyIPLWPL
Lower collections from IPL’s retail customers due to credits on customers’ bills related to production tax credits through its fuel-related cost recovery mechanism($116)($116)$—
Lower collections from IPL’s retail customers due to credits on customers’ bills related to the tax benefit rider(53)(53)—
Changes in income taxes paid/received (a)(50)(20)(43)
Changes in interest payments(47)(31)(13)
Restructuring and voluntary employee separation payments in 2025(25)(11)(12)
Lower collections from IPL’s retail customers due to discontinuation of renewable energy rider in 2024(23)(23)—
Changes in gas stored underground and prepaid gas costs(23)(10)(13)
Higher collections from IPL’s and WPL’s retail electric and IPL’s retail gas base rate increases32527748
Increased collections from IPL’s and WPL’s retail customers caused by temperature impacts on electric and gas sales402317
Other (primarily due to other changes in working capital)(41)22(62)
($13)$58($78)

(a)Refer to the cash flows statements for details of renewable tax credits transferred to other corporate taxpayers during the nine months ended September 30, 2025 and 2024.

Investing Activities - The following items contributed to increased (decreased) investing activity cash flows for the nine months ended September 30, 2025 compared to the same period in 2024 (in millions):

Alliant EnergyIPLWPL
Purchases of short-term investments in 2025($250)$—$—
(Higher) lower utility construction and acquisition expenditures (a)(207)(274)67
Proceeds from sales of partial ownership interests in West Riverside in 2024(123)—(123)
Changes in the amount of cash receipts on sold receivables(67)(67)—
Other(18)13(10)
($665)($328)($66)

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

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 2025 through 2029 are currently anticipated as follows (in millions), which are focused on adding renewable generation and energy storage projects and dispatchable gas generation projects to meet growing customer demand for electricity, 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.

37

Table of Contents

Alliant EnergyIPLWPL
202520262027202820292025202620272028202920252026202720282029
Generation:
Renewables and energy storage projects$940$875$1,135$1,545$820$615$445$530$275$655$310$480$605$1,270$165
Gas projects4001,0551,5051,1809852306901,130920440120330375260545
Other1551801351751008080805545751005512055
Distribution:
Electric systems620550545570615355275260265275265275285305340
Gas systems11013514510510565708040404565656565
Other24525020022028050404040603540354055
$2,470$3,045$3,665$3,795$2,905$1,395$1,600$2,120$1,595$1,515$850$1,290$1,420$2,060$1,225

Financing Activities - The following items contributed to increased (decreased) financing activity cash flows for the nine months ended September 30, 2025 compared to the same period in 2024 (in millions):

Alliant EnergyIPLWPL
Higher (lower) net proceeds from issuance of long-term debt$561$245($297)
(Higher) lower payments to retire long-term debt5(300)—
Higher (lower) capital contributions from IPL’s and WPL’s parent company, Alliant Energy—(40)25
Net changes in the amount of commercial paper outstanding(221)(50)327
Higher common stock dividends(22)(119)(16)
Other10113
$333($253)$42

FERC Financing Authorization - In August 2025, IPL received authorization from FERC to increase the long-term debt securities issuances in 2024 and 2025 to $1,950 million. The remaining capacity as of September 30, 2025 is $400 million.

Common Stock Issuances and Common Stock Dividends - Refer to Note 6 for discussion of common stock issuances by Alliant Energy in 2025 and Alliant Energy’s at-the-market offering program. Refer to “Results of Operations” for discussion of expected future issuances of common stock from 2026 through 2029 and common stock dividends in 2026.

Long-term Debt - Refer to Note 7(b) for discussion of AEF’s term loan credit agreements and various issuances and/or retirements of long-term debt by Alliant Energy and IPL in 2025. Refer to “Results of Operations” for discussion of expected future issuances and retirements of long-term debt by the end of 2026.

Impact of Credit Ratings on Liquidity and Collateral Obligations -

Ratings Triggers - In March 2025, Standard & Poor’s Ratings Services changed certain Alliant Energy, IPL and WPL credit ratings and outlooks, which are not expected to have a material impact on Alliant Energy’s, IPL’s and WPL’s liquidity or collateral obligations, and the current credit ratings and outlooks are as follows:

Standard & Poor’s Ratings Services
Alliant Energy:Corporate/issuerBBB+
Commercial paperA-2
Senior unsecured long-term debtBBB
OutlookStable
IPL:Corporate/issuerBBB+
Commercial paperA-2
Senior unsecured long-term debtBBB+
OutlookStable
WPL:Corporate/issuerA-
Commercial paperA-2
Senior unsecured long-term debtA-
OutlookStable

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 2024 Form 10-K and has not changed materially from the items reported in the 2024 Form 10-K, except for the items described in Notes 4, 7 and 13.

38

Table of Contents

OTHER MATTERS

Critical Accounting Estimates - The summary of critical accounting estimates included in the 2024 Form 10-K has not changed materially, except as described below.

Long-Lived Assets -

Regulated Operations -

Generating Units Subject to Early Retirement - WPL currently plans to continue coal operations at Columbia Units 1 and 2 at least through 2029 as well as evaluate the potential conversion of Columbia Unit 1 and/or Unit 2 to natural gas. WPL previously planned to cease coal operations at Columbia Units 1 and 2 by the end of 2029. As a result, Alliant Energy and WPL concluded that Columbia Units 1 and 2 no longer meet the criteria to be considered probable of abandonment as of September 30, 2025. Refer to Note 3 for further discussion of Columbia Units 1 and 2.

Solar Generation Projects Recently Completed - Construction costs associated with WPL’s approximately 1,100 MW of new solar generation exceeded the construction cost estimates previously approved by the PSCW by approximately $205 million. In September 2025, WPL filed a settlement agreement with the PSCW for the 2026/2027 forward-looking Test Period. In November 2025, the PSCW issued an oral decision approving the settlement agreement, which includes a full return of and on these solar generation construction costs from WPL’s retail electric customers. As a result, Alliant Energy and WPL concluded that there was not a probable disallowance of the higher rate base amounts as of September 30, 2025. Refer to Note 3 for further discussion.

Retroactive Tariffs on Solar Cells and Modules - In August 2023, the U.S. Department of Commerce (DOC) issued a final ruling that found solar cells and modules produced in certain Southeast Asian countries, including Cambodia, Malaysia, Thailand and Vietnam, using parts and components produced in China, were circumventing pre-existing antidumping and countervailing duties on China. Consistent with a June 2022 Presidential Proclamation, the DOC issued rules granting duty-free treatment of solar cells and modules imported from these four countries as of June 2022 until June 2024. In August 2025, the U.S. Court of International Trade (CIT) ruled that this two-year duty suspension, as issued, was impermissible. In September 2025, this ruling from the CIT was appealed to the Federal Circuit. The CIT's order has been stayed pending appeal. Alliant Energy, IPL and WPL continue to assess the potential impact of these tariffs on previously completed solar generation projects and are currently unable to predict with certainty the future outcome or impact of these matters, including resolution of ongoing litigation.

Previous: Item 1. CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (UNAUDITED) · Next: Item 3. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK