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Table of Contents
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

FORM 10-Q

☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
For the quarterly period ended September 30, 2023
or
☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
For the transition period from to
Name of Registrant, State of Incorporation, Address of Principal Executive Offices, Telephone Number, Commission File Number, IRS Employer Identification Number
ALLIANT ENERGY CORPORATION
(a Wisconsin Corporation)
4902 N. Biltmore Lane
Madison, Wisconsin 53718
Telephone (608) 458-3311
Commission File Number - 1-9894
IRS Employer Identification Number - 39-1380265
INTERSTATE POWER & LIGHT COMPANY
(an Iowa corporation)
Alliant Energy Tower
Cedar Rapids, Iowa 52401
Telephone (319) 786-4411
Commission File Number - 1-4117
IRS Employer Identification Number - 42-0331370
WISCONSIN POWER & LIGHT COMPANY
(a Wisconsin corporation)
4902 N. Biltmore Lane
Madison, Wisconsin 53718
Telephone (608) 458-3311
Commission File Number - 0-337
IRS Employer Identification Number - 39-0714890
This combined Form 10-Q is separately filed by Alliant Energy Corporation, Interstate Power and Light Company and Wisconsin Power and Light Company. Information contained in the Form 10-Q relating to Interstate Power and Light Company and Wisconsin Power and Light Company is filed by each such registrant on its own behalf. Each of Interstate Power and Light Company and Wisconsin Power and Light Company makes no representation as to information relating to registrants other than itself.
Securities registered pursuant to Section 12(b) of the Act:
Alliant Energy Corporation, Common Stock, $0.01 Par Value, Trading Symbol LNT, Nasdaq Global Select Market
Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.
Alliant Energy Corporation - Yes ☒ No ☐
Interstate Power and Light Company - Yes ☒ No ☐
Wisconsin Power and Light Company - Yes ☒ No ☐
Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).
Alliant Energy Corporation - Yes ☒ No ☐
Interstate Power and Light Company - Yes ☒ No ☐
Wisconsin Power and Light Company - Yes ☒ No ☐
Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.
Alliant Energy Corporation - Large Accelerated Filer ☒ Accelerated Filer ☐ Non-accelerated Filer ☐ Smaller Reporting Company ☐ Emerging Growth Company ☐
Interstate Power and Light Company - Large Accelerated Filer ☐ Accelerated Filer ☐ Non-accelerated Filer ☒ Smaller Reporting Company ☐ Emerging Growth Company ☐
Wisconsin Power and Light Company - Large Accelerated Filer ☐ Accelerated Filer ☐ Non-accelerated Filer ☒ Smaller Reporting Company ☐ Emerging Growth Company ☐
If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.
Alliant Energy Corporation ☐
Interstate Power and Light Company ☐
Wisconsin Power and Light Company ☐
Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).
Alliant Energy Corporation - Yes ☐ No ☒
Interstate Power and Light Company - Yes ☐ No ☒
Wisconsin Power and Light Company - Yes ☐ No ☒
Number of shares outstanding of each class of common stock as of September 30, 2023:
Alliant Energy Corporation, Common Stock, $0.01 par value, 255,179,087 shares outstanding
Interstate Power and Light Company, Common Stock, $2.50 par value, 13,370,788 shares outstanding (all outstanding shares are owned beneficially and of record by Alliant Energy Corporation)
Wisconsin Power and Light Company, Common Stock, $5 par value, 13,236,601 shares outstanding (all outstanding shares are owned beneficially and of record by Alliant Energy Corporation)

Table of Contents
TABLE OF CONTENTS

| Page
Definitions | 1
Forward-looking Statements | 1
Part I. Financial Information | 3
Item 1. Condensed Consolidated Financial Statements (Unaudited) | 3
Alliant Energy Corporation | 3
Interstate Power and Light Company | 6
Wisconsin Power and Light Company | 9
Combined Notes to Condensed Consolidated Financial Statements | 12
1. Summary of Significant Accounting Policies | 12
2. Regulatory Matters | 12
3. Property, Plant and Equipment | 13
4. Receivables | 13
5. Investments | 14
6. Common Equity | 14
7. Debt | 16
8. Revenues | 18
9. Income Taxes | 18
10. Benefit Plans | 19
1 1. Derivative Instruments | 20
1 2. Fair Value Measurements | 21
1 3. Commitments and Contingencies | 24
1 4. Segments of Business | 25
1 5. Related Parties | 27
Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations | 27
Item 3. Quantitative and Qualitative Disclosures About Market Risk | 37
Item 4. Controls and Procedures | 37
Part II. Other Information | 37
Item 1. Legal Proceedings | 37
Item 1A. Risk Factors | 37
Item 2. Unregistered Sales of Equity Securities and Use of Proceeds | 37
Item 5. Other Information | 37
Item 6. Exhibits | 38
Signatures | 38

Table of Contents
DEFINITIONS
The following abbreviations or acronyms used in this report are defined below:

Abbreviation or Acronym | Definition | Abbreviation or Acronym | Definition
2022 Form 10-K | Combined Annual Report on Form 10-K filed by Alliant Energy, IPL and WPL for the year ended Dec. 31, 2022 | IUB | Iowa Utilities Board
AEF | Alliant Energy Finance, LLC | MDA | Management’s Discussion and Analysis of Financial Condition and Results of Operations
AFUDC | Allowance for funds used during construction | MISO | Midcontinent Independent System Operator, Inc.
Alliant Energy | Alliant Energy Corporation | MW | Megawatt
ATC | American Transmission Company LLC | MWh | Megawatt-hour
ATC Holdings | Interest in American Transmission Company LLC and ATC Holdco LLC | N/A | Not applicable
Corporate Services | Alliant Energy Corporate Services, Inc. | Note(s) | Combined Notes to Condensed Consolidated Financial Statements
Dth | Dekatherm | OPEB | Other postretirement benefits
EGU | Electric generating unit | PPA | Purchased power agreement
EPA | U.S. Environmental Protection Agency | PSCW | Public Service Commission of Wisconsin
EPS | Earnings per weighted average common share | SEC | Securities and Exchange Commission
Financial Statements | Condensed Consolidated Financial Statements | U.S. | United States of America
FTR | Financial transmission right | West Riverside | West Riverside Energy Center and Solar Facility
GAAP | U.S. generally accepted accounting principles | Whiting Petroleum | Whiting Petroleum Corporation
IPL | Interstate Power and Light Company | WPL | Wisconsin Power and Light Company

FORWARD-LOOKING STATEMENTS
Statements contained in this report that are not of historical fact are forward-looking statements intended to qualify for the safe harbors from liability established by the Private Securities Litigation Reform Act of 1995. These forward-looking statements can be identified as such because the statements include words such as “may,” “believe,” “expect,” “anticipate,” “plan,” “project,” “will,” “projections,” “estimate,” or other words of similar import. Similarly, statements that describe future financial performance or plans or strategies are forward-looking statements. Such forward-looking statements are subject to certain risks and uncertainties that could cause actual results to differ materially from those expressed in, or implied by, such statements. Some, but not all, of the risks and uncertainties of Alliant Energy, IPL and WPL that could materially affect actual results include:
•the direct or indirect effects resulting from cybersecurity incidents or attacks on Alliant Energy, IPL, WPL, or their suppliers, contractors and partners, or responses to such incidents;
•the impact of customer- and third party-owned generation, including alternative electric suppliers, in IPL’s and WPL’s service territories on system reliability, operating expenses and customers’ demand for electricity;
•the impact of energy efficiency, franchise retention and customer disconnects on sales volumes and margins;
•the impact that price changes may have on IPL’s and WPL’s customers’ demand for electric, gas and steam services and their ability to pay their bills;
•inflation and higher interest rates;
•changes in the price of delivered natural gas, transmission, purchased electricity and delivered coal, particularly during elevated market prices, and any resulting changes to counterparty credit risk, due to shifts in supply and demand caused by market conditions, regulations and MISO’s seasonal resource adequacy process;
•IPL’s and WPL’s ability to obtain adequate and timely rate relief to allow for, among other things, the recovery of and/or the return on costs, including fuel costs, operating costs, transmission costs, capacity costs, deferred expenditures, deferred tax assets, tax expense, interest expense, capital expenditures, and remaining costs related to EGUs that may be permanently closed and certain other retired assets, decreases in sales volumes, earning their authorized rates of return, and the payments to their parent of expected levels of dividends;
•the ability to obtain regulatory approval for construction projects with acceptable conditions;
•the ability to complete construction of renewable generation and storage projects by planned in-service dates and within the cost targets set by regulators due to cost increases of and access to materials, equipment and commodities, which could result from tariffs, duties or other assessments, such as any additional tariffs resulting from U.S. Department of Commerce investigations into and any decisions made regarding the sourcing of solar project materials and equipment from certain countries, labor issues or supply shortages, the ability to successfully resolve warranty issues or contract disputes, the ability to achieve the expected level of tax benefits based on tax guidelines, project costs and the level of electricity output generated by qualifying generating facilities, and the ability to efficiently utilize the renewable generation and storage project tax benefits for the benefit of customers;
•the ability to utilize tax credits generated to date, and those that may be generated in the future, before they expire, as well as the ability to transfer tax credits that may be generated in the future at adequate pricing;
•disruptions to ongoing operations and the supply of materials, services, equipment and commodities needed to construct solar generation, battery storage and electric and gas distribution projects, which may result from geopolitical issues, supplier manufacturing constraints, labor issues or transportation issues, and thus affect the ability to meet capacity requirements and result in increased capacity expense;
•the future development of technologies related to electrification, and the ability to reliably store and manage electricity;
•federal and state regulatory or governmental actions, including the impact of legislation, and regulatory agency orders;
•the impacts of changes in the tax code, including tax rates, minimum tax rates, adjustments made to deferred tax assets and liabilities, and changes impacting the availability of renewable tax credits;

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•employee workforce factors, including the ability to hire and retain employees with specialized skills, impacts from employee retirements, changes in key executives, ability to create desired corporate culture, collective bargaining agreements and negotiations, work stoppages or restructurings;
•disruptions in the supply and delivery of natural gas, purchased electricity and coal;
•changes to the creditworthiness of, or performance of obligations by, counterparties with which Alliant Energy, IPL and WPL have contractual arrangements, including participants in the energy markets and fuel suppliers and transporters;
•the impact of penalties or third-party claims related to, or in connection with, a failure to maintain the security of personally identifiable information, including associated costs to notify affected persons and to mitigate their information security concerns;
•impacts that terrorist attacks may have on Alliant Energy’s, IPL’s and WPL’s operations and recovery of costs associated with restoration activities, or on the operations of Alliant Energy’s investments;
•any material post-closing paym ents related to any past asset divestitures, including the sale of Whiting Petroleum, which could result from, among other things, indemnification agreements, warranties, guarantees or litigation;
•weather effects on results of utility operations;
•continued access to the capital markets on competitive terms and rates, and the actions of credit rating agencies;
•changes to MISO’s resource adequacy process establishing capacity planning reserve margin and capacity accreditation requirements that may impact how and when new and existing generating facilities, including IPL’s and WPL’s additional solar generation, may be accredited with energy capacity, and may require IPL and WPL to adjust their current resource plans, to add resources to meet the requirements of MISO’s process, or procure capacity in the market whereby such costs might not be recovered in rates;
•issues associated with environmental remediation and environmental compliance, including compliance with all environmental and emissions permits and future changes in environmental laws and regulations, including changes to the Coal Combustion Residuals Rule, Cross-State Air Pollution Rule and federal, state or local regulations for greenhouse gases emissions reductions from new and existing fossil-fueled EGUs under the Clean Air Act, and litigation associated with environmental requirements;
•increased pressure from customers, investors and other stakeholders to more rapidly reduce greenhouse gases emissions;
•the ability to defend against environmental claims brought by state and federal agencies, such as the EPA and state natural resources agencies, or third parties, such as the Sierra Club, and the impact on operating expenses of defending and resolving such claims;
•the direct or indirect effects resulting from breakdown or failure of equipment in the operation of electric and gas distribution systems, such as mechanical problems and explosions or fires, and compliance with electric and gas transmission and distribution safety regulations, including regulations promulgated by the Pipeline and Hazardous Materials Safety Administration;
•issues related to the availability and operations of EGUs, including start-up risks, breakdown or failure of equipment, availability of warranty coverage and successful resolution of warranty issues or contract disputes for equipment breakdowns or failures, performance below expected or contracted levels of output or efficiency, operator error, employee safety, transmission constraints, compliance with mandatory reliability standards and risks related to recovery of resulting incremental operating, fuel-related and capital costs through rates;
•impacts that excessive heat, excessive cold, storms, wildfires, or natural disasters may have on Alliant Energy’s, IPL’s and WPL’s operations and construction activities, and recovery of costs associated with restoration activities, or on the operations of Alliant Energy’s investments;
•the direct or indirect effects resulting from the ongoing novel coronavirus (COVID-19) pandemic and the spread of variant strains;
•Alliant Energy’s ability to sustain its dividend payout ratio goal;
•changes to costs of providing benefits and related funding requirements of pension and OPEB plans due to the market value of the assets that fund the plans, economic conditions, financial market performance, interest rates, timing and form of benefits payments, life expectancies and demographics;
•material changes in employee-related benefit and compensation costs, including settlement losses related to pension plans;
•risks associated with operation and ownership of non-utility holdings;
•changes in technology that alter the channels through which customers buy or utilize Alliant Energy’s, IPL’s or WPL’s products and services;
•impacts on equity income from unconsolidated investments from changes in valuations of the assets held, as well as potential changes to ATC’s authorized return on equity;
•impacts of IPL’s future tax benefits from Iowa rate-making practices, including deductions for repairs expenditures, allocation of mixed service costs and state depreciation, and recoverability of the associated regulatory assets from customers, when the differences reverse in future periods;
•current or future litigation, regulatory investigations, proceedings or inquiries;
•reputational damage from negative publicity, protests, fines, penalties and other negative consequences resulting in regulatory and/or legal actions;
•the effect of accounting standards issued periodically by standard-setting bodies;
•the ability to successfully complete tax audits and changes in tax accounting methods with no material impact on earnings and cash flows; and
•other factors listed in MDA and Risk Factors in Item 1A in the 2022 Form 10-K.
Alliant Energy, IPL and WPL each assume no obligation, and disclaim any duty, to update the forward-looking statements in this report, except as required by law.
Available Information. Alliant Energy routinely posts important information on its website and considers the Investors section of its website, www.alliantenergy.com/investors, a channel of distribution for material information. Information contained on Alliant Energy’s website is not incorporated herein.

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PART I. FINANCIAL INFORMATION
ITEM 1. CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (UNAUDITED)
ALLIANT ENERGY CORPORATION
CONDENSED CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED)

| For the Three Months |  | For the Nine Months
| Ended September 30, |  | Ended September 30,
| 2023 |  | 2022 |  | 2023 |  | 2022
| (in millions, except per share amounts)
Revenues: |  |  |  |  |  |  |
Electric utility | $995 |  | $1,039 |  | $2,562 |  | $2,624
Gas utility | 47 |  | 62 |  | 400 |  | 418
Other utility | 13 |  | 11 |  | 38 |  | 35
Non-utility | 22 |  | 23 |  | 66 |  | 70
Total revenues | 1,077 |  | 1,135 |  | 3,066 |  | 3,147
Operating expenses: |  |  |  |  |  |  |
Electric production fuel and purchased power | 231 |  | 274 |  | 553 |  | 633
Electric transmission service | 154 |  | 157 |  | 438 |  | 428
Cost of gas sold | 12 |  | 26 |  | 226 |  | 242
Other operation and maintenance | 160 |  | 172 |  | 499 |  | 492
Depreciation and amortization | 170 |  | 169 |  | 503 |  | 501
Taxes other than income taxes | 28 |  | 28 |  | 87 |  | 82
Total operating expenses | 755 |  | 826 |  | 2,306 |  | 2,378
Operating income | 322 |  | 309 |  | 760 |  | 769
Other (income) and deductions: |  |  |  |  |  |  |
Interest expense | 99 |  | 83 |  | 289 |  | 235
Equity income from unconsolidated investments, net | (14) |  | (5) |  | (45) |  | (37)
Allowance for funds used during construction | (28) |  | (10) |  | (71) |  | (34)
Other | 1 |  | — |  | 2 |  | —
Total other (income) and deductions | 58 |  | 68 |  | 175 |  | 164
Income before income taxes | 264 |  | 241 |  | 585 |  | 605
Income tax expense | 5 |  | 14 |  | 3 |  | 26
Net income attributable to Alliant Energy common shareowners | $259 |  | $227 |  | $582 |  | $579
Weighted average number of common shares outstanding: |  |  |  |  |  |  |
Basic | 253.5 |  | 251.0 |  | 252.1 |  | 250.8
Diluted | 253.8 |  | 251.3 |  | 252.4 |  | 251.1
Earnings per weighted average common share attributable to Alliant Energy common shareowners (basic and diluted) | $1.02 |  | $0.90 |  | $2.31 |  | $2.31

Refer to accompanying Combined Notes to Condensed Consolidated Financial Statements.

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ALLIANT ENERGY CORPORATION
CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED)

| September 30, 2023 |  | December 31, 2022
| (in millions, except per share and share amounts)
ASSETS |  |  |
Current assets: |  |  |
Cash and cash equivalents | $206 |  | $20
Accounts receivable, less allowance for expected credit losses | 486 |  | 516
Production fuel, at weighted average cost | 44 |  | 53
Gas stored underground, at weighted average cost | 87 |  | 132
Materials and supplies, at weighted average cost | 196 |  | 140
Regulatory assets | 179 |  | 166
Other | 174 |  | 223
Total current assets | 1,372 |  | 1,250
Property, plant and equipment, net | 16,633 |  | 16,247
Investments: |  |  |
ATC Holdings | 380 |  | 358
Other | 214 |  | 201
Total investments | 594 |  | 559
Other assets: |  |  |
Regulatory assets | 2,090 |  | 1,880
Deferred charges and other | 215 |  | 227
Total other assets | 2,305 |  | 2,107
Total assets | $20,904 |  | $20,163

LIABILITIES AND EQUITY |  |  |
Current liabilities: |  |  |
Current maturities of long-term debt | $409 |  | $408
Commercial paper | 451 |  | 642
Other short-term borrowings | 50 |  | —
Accounts payable | 604 |  | 756
Regulatory liabilities | 92 |  | 206
Other | 329 |  | 351
Total current liabilities | 1,935 |  | 2,363
Long-term debt, net (excluding current portion) | 8,429 |  | 7,668
Other liabilities: |  |  |
Deferred tax liabilities | 1,913 |  | 1,943
Regulatory liabilities | 1,095 |  | 1,118
Pension and other benefit obligations | 262 |  | 277
Other | 544 |  | 518
Total other liabilities | 3,814 |  | 3,856
Commitments and contingencies (Note 1 3) |  |  |
Equity: |  |  |
Alliant Energy Corporation common equity: |  |  |
Common stock - $0.01 par value - 480,000,000 shares authorized; 255,179,087 and 251,134,966 shares outstanding | 3 |  | 3
Additional paid-in capital | 2,982 |  | 2,777
Retained earnings | 3,750 |  | 3,509
Accumulated other comprehensive income | 4 |  | —
Shares in deferred compensation trust - 393,781 and 402,134 shares at a weighted average cost of $34.13 and $32.63 per share | (13) |  | (13)
Total Alliant Energy Corporation common equity | 6,726 |  | 6,276
Total liabilities and equity | $20,904 |  | $20,163

Refer to accompanying Combined Notes to Condensed Consolidated Financial Statements.

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ALLIANT ENERGY CORPORATION
CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED)

| For the Nine Months
| Ended September 30,
| 2023 |  | 2022
| (in millions)
Cash flows from operating activities: |  |  |
Net income | $582 |  | $579
Adjustments to reconcile net income to net cash flows from operating activities: |  |  |
Depreciation and amortization | 503 |  | 501
Equity component of allowance for funds used during construction | (53) |  | (25)
Other | 15 |  | 25
Other changes in assets and liabilities: |  |  |
Accounts receivable | (279) |  | (425)
Materials and supplies | (56) |  | (13)
Derivative assets | 102 |  | (184)
Regulatory assets | 40 |  | (102)
Accounts payable | (91) |  | 90
Derivative liabilities | (13) |  | 89
Regulatory liabilities | (126) |  | 89
Other | (2) |  | (139)
Net cash flows from operating activities | 622 |  | 485
Cash flows used for investing activities: |  |  |
Construction and acquisition expenditures: |  |  |
Utility business | (1,201) |  | (873)
Other | (92) |  | (69)
Cash receipts on sold receivables | 306 |  | 358
Proceeds from sales of partial ownership interest in West Riverside | 120 |  | —
Other | (85) |  | (15)
Net cash flows used for investing activities | (952) |  | (599)
Cash flows from financing activities: |  |  |
Common stock dividends | (341) |  | (322)
Proceeds from issuance of common stock, net | 201 |  | 19
Proceeds from issuance of long-term debt | 1,158 |  | 1,238
Payments to retire long-term debt | (404) |  | (379)
Net change in commercial paper and other short-term borrowings | (141) |  | (132)
Contributions from noncontrolling interest | — |  | 29
Distributions to noncontrolling interest | — |  | (29)
Other | 42 |  | (3)
Net cash flows from financing activities | 515 |  | 421
Net increase in cash, cash equivalents and restricted cash | 185 |  | 307
Cash, cash equivalents and restricted cash at beginning of period | 24 |  | 40
Cash, cash equivalents and restricted cash at end of period | $209 |  | $347
Supplemental cash flows information: |  |  |
Cash paid during the period for: |  |  |
Interest | ($280) |  | ($220)
Income taxes, net | ($6) |  | ($7)
Significant non-cash investing and financing activities: |  |  |
Accrued capital expenditures | $287 |  | $403
Beneficial interest obtained in exchange for securitized accounts receivable | $236 |  | $248

Refer to accompanying Combined Notes to Condensed Consolidated Financial Statements.

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INTERSTATE POWER AND LIGHT COMPANY
CONDENSED CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED)

| For the Three Months |  | For the Nine Months
| Ended September 30, |  | Ended September 30,
| 2023 |  | 2022 |  | 2023 |  | 2022
| (in millions)
Revenues: |  |  |  |  |  |  |
Electric utility | $551 |  | $596 |  | $1,370 |  | $1,438
Gas utility | 31 |  | 33 |  | 224 |  | 224
Steam and other | 12 |  | 11 |  | 36 |  | 34
Total revenues | 594 |  | 640 |  | 1,630 |  | 1,696
Operating expenses: |  |  |  |  |  |  |
Electric production fuel and purchased power | 99 |  | 140 |  | 213 |  | 290
Electric transmission service | 115 |  | 115 |  | 316 |  | 303
Cost of gas sold | 12 |  | 14 |  | 127 |  | 126
Other operation and maintenance | 84 |  | 90 |  | 264 |  | 260
Depreciation and amortization | 97 |  | 95 |  | 288 |  | 285
Taxes other than income taxes | 14 |  | 15 |  | 43 |  | 43
Total operating expenses | 421 |  | 469 |  | 1,251 |  | 1,307
Operating income | 173 |  | 171 |  | 379 |  | 389
Other (income) and deductions: |  |  |  |  |  |  |
Interest expense | 38 |  | 37 |  | 113 |  | 111
Allowance for funds used during construction | (6) |  | (3) |  | (13) |  | (8)
Other | 2 |  | (1) |  | 3 |  | (2)
Total other (income) and deductions | 34 |  | 33 |  | 103 |  | 101
Income before income taxes | 139 |  | 138 |  | 276 |  | 288
Income tax benefit | (31) |  | (16) |  | (55) |  | (39)
Net income | $170 |  | $154 |  | $331 |  | $327

Earnings per share data is not disclosed given Alliant Energy Corporation is the sole shareowner of all shares of IPL’s common stock outstanding during the periods presented.
Refer to accompanying Combined Notes to Condensed Consolidated Financial Statements.

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INTERSTATE POWER AND LIGHT COMPANY
CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED)

| September 30, 2023 |  | December 31, 2022
| (in millions, except per share and share amounts)
ASSETS |  |  |
Current assets: |  |  |
Cash and cash equivalents | $188 |  | $15
Accounts receivable, less allowance for expected credit losses | 258 |  | 259
Production fuel, at weighted average cost | 22 |  | 23
Gas stored underground, at weighted average cost | 40 |  | 60
Materials and supplies, at weighted average cost | 111 |  | 83
Regulatory assets | 86 |  | 85
Other | 70 |  | 93
Total current assets | 775 |  | 618
Property, plant and equipment, net | 8,042 |  | 8,046
Other assets: |  |  |
Regulatory assets | 1,504 |  | 1,301
Deferred charges and other | 106 |  | 110
Total other assets | 1,610 |  | 1,411
Total assets | $10,427 |  | $10,075

LIABILITIES AND EQUITY |  |  |
Current liabilities: |  |  |
Accounts payable | $255 |  | $239
Accounts payable to associated companies | 59 |  | 28
Accrued taxes | 68 |  | 52
Accrued interest | 41 |  | 35
Regulatory liabilities | 63 |  | 114
Other | 84 |  | 113
Total current liabilities | 570 |  | 581
Long-term debt, net | 3,944 |  | 3,646
Other liabilities: |  |  |
Deferred tax liabilities | 987 |  | 1,047
Regulatory liabilities | 592 |  | 640
Pension and other benefit obligations | 59 |  | 62
Other | 286 |  | 291
Total other liabilities | 1,924 |  | 2,040
Commitments and contingencies (Note 1 3) |  |  |
Equity: |  |  |
Interstate Power and Light Company common equity: |  |  |
Common stock - $2.50 par value - 24,000,000 shares authorized; 13,370,788 shares outstanding | 33 |  | 33
Additional paid-in capital | 2,867 |  | 2,807
Retained earnings | 1,089 |  | 968
Total Interstate Power and Light Company common equity | 3,989 |  | 3,808
Total liabilities and equity | $10,427 |  | $10,075

Refer to accompanying Combined Notes to Condensed Consolidated Financial Statements.

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INTERSTATE POWER AND LIGHT COMPANY
CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED)

| For the Nine Months
| Ended September 30,
| 2023 |  | 2022
| (in millions)
Cash flows from operating activities: |  |  |
Net income | $331 |  | $327
Adjustments to reconcile net income to net cash flows from operating activities: |  |  |
Depreciation and amortization | 288 |  | 285
Deferred tax benefit and tax credits | (17) |  | (24)
Other | (6) |  | (8)
Other changes in assets and liabilities: |  |  |
Accounts receivable | (306) |  | (397)
Derivative assets | 53 |  | (118)
Regulatory assets | 55 |  | 18
Accounts payable | (45) |  | 71
Derivative liabilities | (25) |  | 62
Regulatory liabilities | (90) |  | 61
Deferred income taxes | (44) |  | (30)
Other | (3) |  | (81)
Net cash flows from operating activities | 191 |  | 166
Cash flows from (used for) investing activities: |  |  |
Construction and acquisition expenditures | (427) |  | (269)
Cash receipts on sold receivables | 306 |  | 358
Other | (56) |  | (5)
Net cash flows from (used for) investing activities | (177) |  | 84
Cash flows from (used for) financing activities: |  |  |
Common stock dividends | (210) |  | (240)
Capital contributions from parent | 60 |  | —
Proceeds from issuance of long-term debt | 296 |  | —
Other | 13 |  | 1
Net cash flows from (used for) financing activities | 159 |  | (239)
Net increase in cash, cash equivalents and restricted cash | 173 |  | 11
Cash, cash equivalents and restricted cash at beginning of period | 15 |  | 34
Cash, cash equivalents and restricted cash at end of period | $188 |  | $45
Supplemental cash flows information: |  |  |
Cash (paid) refunded during the period for: |  |  |
Interest | ($107) |  | ($111)
Income taxes, net | $36 |  | $33
Significant non-cash investing and financing activities: |  |  |
Accrued capital expenditures | $108 |  | $43
Beneficial interest obtained in exchange for securitized accounts receivable | $236 |  | $248

Refer to accompanying Combined Notes to Condensed Consolidated Financial Statements.

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WISCONSIN POWER AND LIGHT COMPANY
CONDENSED CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED)

| For the Three Months |  | For the Nine Months
| Ended September 30, |  | Ended September 30,
| 2023 |  | 2022 |  | 2023 |  | 2022
| (in millions)
Revenues: |  |  |  |  |  |  |
Electric utility | $444 |  | $443 |  | $1,192 |  | $1,186
Gas utility | 16 |  | 29 |  | 176 |  | 194
Other | 1 |  | — |  | 2 |  | 1
Total revenues | 461 |  | 472 |  | 1,370 |  | 1,381
Operating expenses: |  |  |  |  |  |  |
Electric production fuel and purchased power | 132 |  | 134 |  | 341 |  | 343
Electric transmission service | 39 |  | 42 |  | 122 |  | 125
Cost of gas sold | — |  | 13 |  | 99 |  | 117
Other operation and maintenance | 64 |  | 70 |  | 197 |  | 193
Depreciation and amortization | 71 |  | 71 |  | 208 |  | 211
Taxes other than income taxes | 13 |  | 11 |  | 40 |  | 35
Total operating expenses | 319 |  | 341 |  | 1,007 |  | 1,024
Operating income | 142 |  | 131 |  | 363 |  | 357
Other (income) and deductions: |  |  |  |  |  |  |
Interest expense | 38 |  | 31 |  | 110 |  | 86
Allowance for funds used during construction | (22) |  | (7) |  | (58) |  | (26)
Other | (2) |  | — |  | (3) |  | —
Total other (income) and deductions | 14 |  | 24 |  | 49 |  | 60
Income before income taxes | 128 |  | 107 |  | 314 |  | 297
Income tax expense | 21 |  | 16 |  | 47 |  | 50
Net income | $107 |  | $91 |  | $267 |  | $247

Earnings per share data is not disclosed given Alliant Energy Corporation is the sole shareowner of all shares of WPL’s common stock outstanding during the periods presented.
Refer to accompanying Combined Notes to Condensed Consolidated Financial Statements.

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WISCONSIN POWER AND LIGHT COMPANY
CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED)

| September 30, 2023 |  | December 31, 2022
| (in millions, except per share and share amounts)
ASSETS |  |  |
Current assets: |  |  |
Cash and cash equivalents | $16 |  | $5
Accounts receivable, less allowance for expected credit losses | 214 |  | 244
Production fuel, at weighted average cost | 21 |  | 29
Gas stored underground, at weighted average cost | 47 |  | 73
Materials and supplies, at weighted average cost | 82 |  | 54
Regulatory assets | 93 |  | 81
Prepaid gross receipts tax | 36 |  | 42
Other | 50 |  | 60
Total current assets | 559 |  | 588
Property, plant and equipment, net | 8,085 |  | 7,722
Other assets: |  |  |
Regulatory assets | 586 |  | 579
Deferred charges and other | 71 |  | 98
Total other assets | 657 |  | 677
Total assets | $9,301 |  | $8,987

LIABILITIES AND EQUITY |  |  |
Current liabilities: |  |  |
Commercial paper | $120 |  | $290
Accounts payable | 281 |  | 456
Regulatory liabilities | 29 |  | 92
Other | 117 |  | 111
Total current liabilities | 547 |  | 949
Long-term debt, net | 3,069 |  | 2,770
Other liabilities: |  |  |
Deferred tax liabilities | 796 |  | 789
Regulatory liabilities | 503 |  | 478
Pension and other benefit obligations | 128 |  | 140
Other | 393 |  | 370
Total other liabilities | 1,820 |  | 1,777
Commitments and contingencies (Note 1 3) |  |  |
Equity: |  |  |
Wisconsin Power and Light Company common equity: |  |  |
Common stock - $5 par value - 18,000,000 shares authorized; 13,236,601 shares outstanding | 66 |  | 66
Additional paid-in capital | 2,478 |  | 2,233
Retained earnings | 1,321 |  | 1,192
Total Wisconsin Power and Light Company common equity | 3,865 |  | 3,491
Total liabilities and equity | $9,301 |  | $8,987

Refer to accompanying Combined Notes to Condensed Consolidated Financial Statements.

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WISCONSIN POWER AND LIGHT COMPANY
CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED)

| For the Nine Months
| Ended September 30,
| 2023 |  | 2022
| (in millions)
Cash flows from operating activities: |  |  |
Net income | $267 |  | $247
Adjustments to reconcile net income to net cash flows from operating activities: |  |  |
Depreciation and amortization | 208 |  | 211
Equity component of allowance for funds used during construction | (43) |  | (19)
Other | 5 |  | 23
Other changes in assets and liabilities: |  |  |
Derivative assets | 55 |  | (66)
Regulatory assets | (16) |  | (120)
Accounts payable | (55) |  | 5
Regulatory liabilities | (37) |  | 28
Other | 53 |  | (30)
Net cash flows from operating activities | 437 |  | 279
Cash flows used for investing activities: |  |  |
Construction and acquisition expenditures | (774) |  | (604)
Proceeds from sales of partial ownership interest in West Riverside | 120 |  | —
Other | (26) |  | (8)
Net cash flows used for investing activities | (680) |  | (612)
Cash flows from financing activities: |  |  |
Common stock dividends | (138) |  | (133)
Capital contributions from parent | 245 |  | 420
Proceeds from issuance of long-term debt | 297 |  | 588
Net change in commercial paper | (170) |  | (236)
Contributions from noncontrolling interest | — |  | 29
Distributions to noncontrolling interest | — |  | (29)
Other | 20 |  | (9)
Net cash flows from financing activities | 254 |  | 630
Net increase in cash, cash equivalents and restricted cash | 11 |  | 297
Cash, cash equivalents and restricted cash at beginning of period | 5 |  | 2
Cash, cash equivalents and restricted cash at end of period | $16 |  | $299
Supplemental cash flows information: |  |  |
Cash paid during the period for: |  |  |
Interest | ($106) |  | ($78)
Income taxes, net | ($63) |  | ($51)
Significant non-cash investing and financing activities: |  |  |
Accrued capital expenditures | $172 |  | $355

Refer to accompanying Combined Notes to Condensed Consolidated Financial Statements.

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ALLIANT ENERGY CORPORATION
INTERSTATE POWER AND LIGHT COMPANY
WISCONSIN POWER AND LIGHT COMPANY
COMBINED NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (UNAUDITED)
NOTE 1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
NOTE 1(a) General - The interim unaudited Financial Statements included herein have been prepared pursuant to the rules and regulations of the SEC. Accordingly, certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted, although management believes that the disclosures are adequate to make the information presented not misleading. These Financial Statements should be read in conjunction with the financial statements and the notes thereto included in the 2022 Form 10-K.
In the opinion of management, all adjustments, which unless otherwise noted are normal and recurring in nature, necessary for a fair presentation of the results of operations, financial position and cash flows have been made. Results for the nine months ended September 30, 2023 are not necessarily indicative of results that may be expected for the year ending December 31, 2023.
A change in management’s estimates or assumptions could have a material impact on financial condition and results of operations during the period in which such change occurred. Certain prior period amounts in the Financial Statements and Notes have been reclassified to conform to the current period presentation for comparative purposes.
NOTE 1(b) Cash and Cash Equivalents - At September 30, 2023, Alliant Energy’s, IPL’s and WPL’s cash and cash equivalents included $189 million, $180 million and $9 million of money market fund investments, respectively, with weighted average interest rates of 5%.
NOTE 2. REGULATORY MATTERS
Regulatory Assets and Regulatory Liabilities -
Regulatory assets were comprised of the following items (in millions):

| Alliant Energy |  | IPL |  | WPL
| September 30, 2023 |  | December 31, 2022 |  | September 30, 2023 |  | December 31, 2022 |  | September 30, 2023 |  | December 31, 2022
Tax-related | $919 |  | $929 |  | $825 |  | $848 |  | $94 |  | $81
Pension and OPEB costs | 371 |  | 392 |  | 187 |  | 197 |  | 184 |  | 195
Assets retired early | 282 |  | 70 |  | 267 |  | 53 |  | 15 |  | 17
Asset retirement obligations (AROs) | 199 |  | 151 |  | 155 |  | 110 |  | 44 |  | 41
Commodity cost recovery | 138 |  | 160 |  | 11 |  | 1 |  | 127 |  | 159
Derivatives | 72 |  | 84 |  | 27 |  | 48 |  | 45 |  | 36
IPL’s Duane Arnold Energy Center PPA amendment | 48 |  | 66 |  | 48 |  | 66 |  | — |  | —
WPL’s Western Wisconsin gas distribution expansion investments | 46 |  | 48 |  | — |  | — |  | 46 |  | 48
Other | 194 |  | 146 |  | 70 |  | 63 |  | 124 |  | 83
| $2,269 |  | $2,046 |  | $1,590 |  | $1,386 |  | $679 |  | $660

Tax-related - Refer to Note 9 for discussion of Iowa Tax Reform, which resulted in a decrease in Alliant Energy’s and IPL’s tax-related regulatory assets in the third quarter of 2023.
Assets retired early and Asset retirement obligations - In May 2023, IPL retired the coal-fired Lansing Generating Station and reclassified the remaining net book value of this EGU from property, plant and equipment to a regulatory asset (assets retired early) on Alliant Energy’s and IPL’s balance sheets. The related regulatory asset balance as of September 30, 2023 was $221 million, which is currently included in IPL’s rate base and IPL is earning a return of and a return on the remaining balance. In September 2023, the Federal Energy Regulatory Commission approved continued recovery of the remaining net book value of Lansing from IPL’s wholesale customers. IPL’s retail electric rate review for the October 2024 through September 2025 forward-looking Test Period includes a request for continued recovery of the remaining net book value of Lansing through 2037. In addition, IPL reclassified the remaining net book value of the associated AROs from property, plant and equipment to a regulatory asset (AROs) on Alliant Energy’s and IPL’s balance sheets.
Derivatives - Refer to Note 11 for discussion of changes in Alliant Energy’s, IPL’s and WPL’s derivative liabilities/assets during the nine months ended September 30, 2023, which resulted in comparable changes to regulatory assets/liabilities on the balance sheets.

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Regulatory liabilities were comprised of the following items (in millions):

| Alliant Energy |  | IPL |  | WPL
| September 30, 2023 |  | December 31, 2022 |  | September 30, 2023 |  | December 31, 2022 |  | September 30, 2023 |  | December 31, 2022
Tax-related | $569 |  | $579 |  | $301 |  | $303 |  | $268 |  | $276
Cost of removal obligations | 397 |  | 398 |  | 249 |  | 259 |  | 148 |  | 139
Derivatives | 91 |  | 210 |  | 52 |  | 115 |  | 39 |  | 95
Commodity cost recovery | 41 |  | 40 |  | 11 |  | 38 |  | 30 |  | 2
WPL’s West Riverside liquidated damages | 9 |  | 32 |  | — |  | — |  | 9 |  | 32
Electric transmission cost recovery | 6 |  | 20 |  | 6 |  | 10 |  | — |  | 10
Other | 74 |  | 45 |  | 36 |  | 29 |  | 38 |  | 16
| $1,187 |  | $1,324 |  | $655 |  | $754 |  | $532 |  | $570

WPL’s West Riverside liquidated damages - Pursuant to PSCW authorization, WPL’s amortization of liquidated damages related to West Riverside construction procurement contracts was used to offset increases in WPL’s retail electric 2022/2023 Test Period revenue requirement, which resulted in decreases in regulatory liabilities on Alliant Energy’s and WPL’s balance sheets and decreases in depreciation and amortization expenses in Alliant Energy’s and WPL’s income statements for the three and nine months ended September 30, 2023.
NOTE 3. PROPERTY, PLANT AND EQUIPMENT
In March 2023 and June 2023, Madison Gas and Electric Company and WEC Energy Group, Inc., respectively, acquired partial ownership interests in West Riverside. The related proceeds are included in “Proceeds from sales of partial ownership interest in West Riverside” in investing activities in Alliant Energy’s and WPL’s cash flows statements for the nine months ended September 30, 2023. As a result of these transactions, WPL’s undivided current ownership interest in West Riverside is 73.8%.
NOTE 4. RECEIVABLES
NOTE 4(a) - Accounts Receivable - For the three and nine months ended September 30, 2023, Alliant Energy’s, IPL’s and WPL’s gross write-offs for accounts receivable were as follows (in millions):

| Originated in 2022 |  | Originated in 2023
| Three Months |  | Nine Months |  | Three Months |  | Nine Months
Alliant Energy | $3 |  | $11 |  | $6 |  | $8
IPL | 2 |  | 7 |  | 4 |  | 5
WPL | 1 |  | 4 |  | 2 |  | 3

NOTE 4(b) - Sales of Accounts Receivable - IPL maintains a Receivables Purchase and Sale Agreement (Receivables Agreement) whereby it may sell its customer accounts receivables, unbilled revenues and certain other accounts receivables to a third party through wholly-owned and consolidated special purpose entities. In March 2023, IPL amended and extended through March 2024 the purchase commitment from the third party to which it sells its receivables. The limit on cash proceeds fluctuates between $5 million and $110 million, which IPL may change periodically throughout the year. The transfers of receivables meet the criteria for sale accounting established by the transfer of financial assets accounting rules. As of September 30, 2023, IPL had $109 million of available capacity under its sales of accounts receivable program. IPL’s maximum and average outstanding cash proceeds (based on daily outstanding balances) related to the sales of accounts receivable program for the three and nine months ended September 30 were as follows (in millions):

| Three Months |  | Nine Months
| 2023 |  | 2022 |  | 2023 |  | 2022
Maximum outstanding aggregate cash proceeds | $94 |  | $36 |  | $110 |  | $66
Average outstanding aggregate cash proceeds | 46 |  | 3 |  | 68 |  | 8

The attributes of IPL’s receivables sold under the Receivables Agreement were as follows (in millions):

| September 30, 2023 |  | December 31, 2022
Customer accounts receivable | $161 |  | $145
Unbilled utility revenues | 88 |  | 132
Other receivables | 1 |  | —
Receivables sold to third party | 250 |  | 277
Less: cash proceeds | 1 |  | 80
Deferred proceeds | 249 |  | 197
Less: allowance for expected credit losses | 13 |  | 12
Fair value of deferred proceeds | $236 |  | $185

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As of September 30, 2023, outstanding receivables past due under the Receivables Agreement were $18 million. Additional attributes of IPL’s receivables sold under the Receivables Agreement for the three and nine months ended September 30 were as follows (in millions):

| Three Months |  | Nine Months
| 2023 |  | 2022 |  | 2023 |  | 2022
Collections | $616 |  | $670 |  | $1,720 |  | $1,731
Write-offs, net of recoveries | 5 |  | 3 |  | 9 |  | 6

Effective October 2023, the limit on cash proceeds under the Receivables Agreement is $5 million.
NOTE 5. INVESTMENTS
Unconsolidated Equity Investments - Alliant Energy’s equity (income) loss from unconsolidated investments accounted for under the equity method of accounting for the three and nine months ended September 30 was as follows (in millions):

| Three Months |  | Nine Months
| 2023 |  | 2022 |  | 2023 |  | 2022
ATC Holdings | ($12) |  | ($7) |  | ($37) |  | ($29)
Other | (2) |  | 2 |  | (8) |  | (8)
| ($14) |  | ($5) |  | ($45) |  | ($37)

NOTE 6. COMMON EQUITY
Common Share Activity - A summary of Alliant Energy’s common stock activity was as follows:

Shares outstanding, January 1, 2023 | 251,134,966 |
At-the-market offering program | 3,569,937 |
Shareowner Direct Plan | 339,850 |
Equity-based compensation plans | 134,334 |
Shares outstanding, September 30, 2023 | 255,179,087 |

At-the-Market Offering Program - In December 2022, Alliant Energy filed a prospectus supplement under which it may sell up to $225 million of its common stock through an at-the-market offering program. As of September 30, 2023, Alliant Energy issued 3,569,937 shares of common stock through this program and received cash proceeds of $183 million, net of $2 million in commissions and fees. The proceeds from the issuances of common stock were used for general corporate purposes.
Changes in Shareowners’ Equity - A summary of changes in shareowners’ equity was as follows (in millions):

Alliant Energy | Total Alliant Energy Common Equity |  |  |  |
|  |  |  |  |  |  | Accumulated |  | Shares in |  |  |  |
|  |  | Additional |  |  |  | Other |  | Deferred |  |  |  |
| Common |  | Paid-In |  | Retained |  | Comprehensive |  | Compensation |  | Noncontrolling |  | Total
| Stock |  | Capital |  | Earnings |  | Income |  | Trust |  | Interest |  | Equity
Three Months Ended September 30, 2023 |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning balance, June 30, 2023 | $3 |  | $2,854 |  | $3,606 |  | $3 |  | ($14) |  | $— |  | $6,452
Net income attributable to Alliant Energy common shareowners |  |  |  |  | 259 |  |  |  |  |  |  |  | 259
Common stock dividends ($0.4525 per share) |  |  |  |  | (115) |  |  |  |  |  |  |  | (115)
At-the-market offering program and Shareowner Direct Plan issuances |  |  | 125 |  |  |  |  |  |  |  |  |  | 125
Equity-based compensation plans and other |  |  | 3 |  |  |  |  |  | 1 |  |  |  | 4
Other comprehensive income, net of tax |  |  |  |  |  |  | 1 |  |  |  |  |  | 1
Ending balance, September 30, 2023 | $3 |  | $2,982 |  | $3,750 |  | $4 |  | ($13) |  | $— |  | $6,726
Three Months Ended September 30, 2022 |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning balance, June 30, 2022 | $3 |  | $2,759 |  | $3,387 |  | $— |  | ($12) |  | $29 |  | $6,166
Net income attributable to Alliant Energy common shareowners |  |  |  |  | 227 |  |  |  |  |  |  |  | 227
Common stock dividends ($0.4275 per share) |  |  |  |  | (106) |  |  |  |  |  |  |  | (106)
Shareowner Direct Plan issuances |  |  | 6 |  |  |  |  |  |  |  |  |  | 6
Equity-based compensation plans and other |  |  | 2 |  |  |  |  |  | (1) |  |  |  | 1
Distributions to noncontrolling interest |  |  |  |  |  |  |  |  |  |  | (29) |  | (29)
Ending balance, September 30, 2022 | $3 |  | $2,767 |  | $3,508 |  | $— |  | ($13) |  | $— |  | $6,265

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Alliant Energy | Total Alliant Energy Common Equity |  |  |  |
|  |  |  |  |  |  | Accumulated |  | Shares in |  |  |  |
|  |  | Additional |  |  |  | Other |  | Deferred |  |  |  |
| Common |  | Paid-In |  | Retained |  | Comprehensive |  | Compensation |  | Noncontrolling |  | Total
| Stock |  | Capital |  | Earnings |  | Income |  | Trust |  | Interest |  | Equity
Nine Months Ended September 30, 2023 |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2022 | $3 |  | $2,777 |  | $3,509 |  | $— |  | ($13) |  | $— |  | $6,276
Net income attributable to Alliant Energy common shareowners |  |  |  |  | 582 |  |  |  |  |  |  |  | 582
Common stock dividends ($1.3575 per share) |  |  |  |  | (341) |  |  |  |  |  |  |  | (341)
At-the-market offering program and Shareowner Direct Plan issuances |  |  | 201 |  |  |  |  |  |  |  |  |  | 201
Equity-based compensation plans and other |  |  | 4 |  |  |  |  |  |  |  |  |  | 4
Other comprehensive income, net of tax |  |  |  |  |  |  | 4 |  |  |  |  |  | 4
Ending balance, September 30, 2023 | $3 |  | $2,982 |  | $3,750 |  | $4 |  | ($13) |  | $— |  | $6,726
Nine Months Ended September 30, 2022 |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2021 | $3 |  | $2,749 |  | $3,250 |  | $— |  | ($12) |  | $— |  | $5,990
Net income attributable to Alliant Energy common shareowners |  |  |  |  | 579 |  |  |  |  |  |  |  | 579
Common stock dividends ($1.2825 per share) |  |  |  |  | (322) |  |  |  |  |  |  |  | (322)
Shareowner Direct Plan issuances |  |  | 19 |  |  |  |  |  |  |  |  |  | 19
Equity-based compensation plans and other |  |  | (1) |  | 1 |  |  |  | (1) |  |  |  | (1)
Contributions from noncontrolling interest |  |  |  |  |  |  |  |  |  |  | 29 |  | 29
Distributions to noncontrolling interest |  |  |  |  |  |  |  |  |  |  | (29) |  | (29)
Ending balance, September 30, 2022 | $3 |  | $2,767 |  | $3,508 |  | $— |  | ($13) |  | $— |  | $6,265

IPL |  |  | Additional |  |  |  |  |  | Total
| Common |  | Paid-In |  | Retained |  |  |  | Common
| Stock |  | Capital |  | Earnings |  |  |  | Equity
Three Months Ended September 30, 2023 |  |  |  |  |  |  |  |  |
Beginning balance, June 30, 2023 | $33 |  | $2,847 |  | $989 |  |  |  | $3,869
Net income |  |  |  |  | 170 |  |  |  | 170
Common stock dividends |  |  |  |  | (70) |  |  |  | (70)
Capital contributions from parent |  |  | 20 |  |  |  |  |  | 20
Ending balance, September 30, 2023 | $33 |  | $2,867 |  | $1,089 |  |  |  | $3,989
Three Months Ended September 30, 2022 |  |  |  |  |  |  |  |  |
Beginning balance, June 30, 2022 | $33 |  | $2,807 |  | $942 |  |  |  | $3,782
Net income |  |  |  |  | 154 |  |  |  | 154
Common stock dividends |  |  |  |  | (80) |  |  |  | (80)
Ending balance, September 30, 2022 | $33 |  | $2,807 |  | $1,016 |  |  |  | $3,856

IPL |  |  | Additional |  |  |  |  |  | Total
| Common |  | Paid-In |  | Retained |  |  |  | Common
| Stock |  | Capital |  | Earnings |  |  |  | Equity
Nine Months Ended September 30, 2023 |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2022 | $33 |  | $2,807 |  | $968 |  |  |  | $3,808
Net income |  |  |  |  | 331 |  |  |  | 331
Common stock dividends |  |  |  |  | (210) |  |  |  | (210)
Capital contributions from parent |  |  | 60 |  |  |  |  |  | 60
Ending balance, September 30, 2023 | $33 |  | $2,867 |  | $1,089 |  |  |  | $3,989
Nine Months Ended September 30, 2022 |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2021 | $33 |  | $2,807 |  | $929 |  |  |  | $3,769
Net income |  |  |  |  | 327 |  |  |  | 327
Common stock dividends |  |  |  |  | (240) |  |  |  | (240)
Ending balance, September 30, 2022 | $33 |  | $2,807 |  | $1,016 |  |  |  | $3,856

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WPL | Total WPL Common Equity |  |  |  |
|  |  | Additional |  |  |  |  |  |
| Common |  | Paid-In |  | Retained |  | Noncontrolling |  | Total
| Stock |  | Capital |  | Earnings |  | Interest |  | Equity
Three Months Ended September 30, 2023 |  |  |  |  |  |  |  |  |
Beginning balance, June 30, 2023 | $66 |  | $2,413 |  | $1,260 |  | $— |  | $3,739
Net income |  |  |  |  | 107 |  |  |  | 107
Common stock dividends |  |  |  |  | (46) |  |  |  | (46)
Capital contributions from parent |  |  | 65 |  |  |  |  |  | 65
Ending balance, September 30, 2023 | $66 |  | $2,478 |  | $1,321 |  | $— |  | $3,865
Three Months Ended September 30, 2022 |  |  |  |  |  |  |  |  |
Beginning balance, June 30, 2022 | $66 |  | $1,968 |  | $1,120 |  | $29 |  | $3,183
Net income |  |  |  |  | 91 |  |  |  | 91
Common stock dividends |  |  |  |  | (44) |  |  |  | (44)
Capital contributions from parent |  |  | 155 |  |  |  |  |  | 155
Distributions to noncontrolling interest |  |  |  |  |  |  | (29) |  | (29)
Ending balance, September 30, 2022 | $66 |  | $2,123 |  | $1,167 |  | $— |  | $3,356

WPL | Total WPL Common Equity |  |  |  |
|  |  | Additional |  |  |  |  |  |
| Common |  | Paid-In |  | Retained |  | Noncontrolling |  | Total
| Stock |  | Capital |  | Earnings |  | Interest |  | Equity
Nine Months Ended September 30, 2023 |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2022 | $66 |  | $2,233 |  | $1,192 |  | $— |  | $3,491
Net income |  |  |  |  | 267 |  |  |  | 267
Common stock dividends |  |  |  |  | (138) |  |  |  | (138)
Capital contributions from parent |  |  | 245 |  |  |  |  |  | 245
Ending balance, September 30, 2023 | $66 |  | $2,478 |  | $1,321 |  | $— |  | $3,865
Nine Months Ended September 30, 2022 |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2021 | $66 |  | $1,704 |  | $1,053 |  | $— |  | $2,823
Net income |  |  |  |  | 247 |  |  |  | 247
Common stock dividends |  |  |  |  | (133) |  |  |  | (133)
Capital contributions from parent |  |  | 420 |  |  |  |  |  | 420
Contributions from noncontrolling interest |  |  |  |  |  |  | 29 |  | 29
Distributions to noncontrolling interest |  |  |  |  |  |  | (29) |  | (29)
Other |  |  | (1) |  |  |  |  |  | (1)
Ending balance, September 30, 2022 | $66 |  | $2,123 |  | $1,167 |  | $— |  | $3,356

NOTE 7. DEBT
NOTE 7(a) Short-term Debt - In March 2023, Alliant Energy, IPL and WPL extended their single credit facility agreement, which currently expires in December 2027, and reallocated credit facility capacity amounts to $450 million for Alliant Energy at the parent company level, $250 million for IPL and $300 million for WPL, within the $1 billion total commitment. Information regarding Alliant Energy’s, IPL’s and WPL’s commercial paper classified as short-term debt was as follows (dollars in millions):

September 30, 2023 | Alliant Energy |  | IPL |  | WPL
Amount outstanding | $451 |  | $— |  | $120
Weighted average interest rates | 5.5% |  | —% |  | 5.4%
Available credit facility capacity | $549 |  | $250 |  | $180

| Alliant Energy |  | IPL |  | WPL
Three Months Ended September 30 | 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022
Maximum amount outstanding (based on daily outstanding balances) | $474 |  | $449 |  | $7 |  | $— |  | $125 |  | $251
Average amount outstanding (based on daily outstanding balances) | $440 |  | $353 |  | $— |  | $— |  | $86 |  | $110
Weighted average interest rates | 5.5% |  | 2.4% |  | 5.5% |  | —% |  | 5.4% |  | 2.0%
Nine Months Ended September 30 |  |  |  |  |  |  |  |  |  |  |
Maximum amount outstanding (based on daily outstanding balances) | $793 |  | $577 |  | $70 |  | $— |  | $349 |  | $252
Average amount outstanding (based on daily outstanding balances) | $367 |  | $377 |  | $2 |  | $— |  | $135 |  | $160
Weighted average interest rates | 5.1% |  | 1.2% |  | 5.3% |  | —% |  | 4.9% |  | 0.9%

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In January 2023, AEF received $50 million of proceeds from its December 2022 term loan credit agreement, which was classified as “Other short-term borrowings” on Alliant Energy’s balance sheet as of September 30, 2023.
NOTE 7(b) Long-term Debt - In September 2023, IPL issued $300 million of 5.70% senior debentures due 2033. The net proceeds from IPL’s issuance were used to reduce cash amounts received from its sales of accounts receivable program, reduce commercial paper classified as long-term debt, for general corporate purposes and/or were placed in money market fund investments. In June 2023, AEF retired its $400 million 3.75% senior notes. In March 2023, WPL issued $300 million of 4.95% debentures due 2033. WPL’s debentures were issued as green bonds, and an amount equal to or in excess of the net proceeds were disbursed for the development and acquisition of its solar EGUs.
Convertible Senior Notes - In March 2023, Alliant Energy issued $575 million of 3.875% convertible senior notes (the Notes), which are senior unsecured obligations, and used the net proceeds from the issuance for general corporate purposes. The Notes will mature on March 15, 2026 unless earlier converted or repurchased, and no sinking fund is provided for the Notes. Alliant Energy may not redeem the Notes prior to the maturity date. Holders may convert their Notes at their option at any time prior to the close of business on the business day immediately preceding December 15, 2025 only under the following circumstances:
•during any calendar quarter commencing after the calendar quarter ending on June 30, 2023 (and only during such calendar quarter), if the last reported sale price of Alliant Energy’s common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day during such period;
•during the 5 business day period after any 10 consecutive trading day period (the “measurement period”) in which the trading price (as defined in the related Indenture) per $1,000 principal amount of Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of Alliant Energy’s common stock and the conversion rate on each such trading day; or
•upon the occurrence of specified corporate events.
On or after December 15, 2025 until the close of business on the business day immediately preceding the maturity date, holders may convert all or any portion of their Notes at any time, regardless of the foregoing circumstances. Upon conversion of the Notes, Alliant Energy will pay cash up to the aggregate principal amount of the Notes to be converted and pay or deliver, as the case may be, cash, shares of its common stock or a combination of cash and shares of its common stock, at its election, in respect of the remainder, if any, of its conversion obligation in excess of the aggregate principal amount of the Notes being converted.
The initial conversion rate is 15.5461 shares of common stock per $1,000 principal amount of Notes (equivalent to an initial conversion price of approximately $64.32 per share of Alliant Energy’s common stock). The conversion rate is subject to adjustment in some events but will not be adjusted for any accrued and unpaid interest. In addition, following certain corporate events that occur prior to the maturity date, Alliant Energy will, in certain circumstances, increase the conversion rate for a holder who elects to convert its Notes in connection with such a corporate event.
If Alliant Energy undergoes a fundamental change (as defined in the related Indenture), then, subject to certain conditions, holders of the Notes may require Alliant Energy to repurchase for cash all or any portion of its Notes at a repurchase price equal to 100% of the principal amount of the Notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date.
As of September 30, 2023, the conditions allowing holders of the Notes to convert their Notes were not met, and as a result, the Notes were classified as “Long-term debt, net” on Alliant Energy’s balance sheet. As of September 30, 2023, the net carrying amount of the Notes was $567 million, with unamortized debt issuance costs of $8 million, and the estimated fair value (Level 2) of the Notes was $556 million. As of September 30, 2023, there were no shares of Alliant Energy’s common stock related to the potential conversion of the Notes included in diluted EPS based on Alliant Energy’s average stock prices and the relevant terms of the Notes.

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NOTE 8. REVENUES
Disaggregation of revenues from contracts with customers, which correlates to revenues for each reportable segment, was as follows (in millions):

| Alliant Energy |  | IPL |  | WPL
Three Months Ended September 30 | 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022
Electric Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | $374 |  | $376 |  | $209 |  | $222 |  | $165 |  | $154
Retail - commercial | 241 |  | 243 |  | 158 |  | 165 |  | 83 |  | 78
Retail - industrial | 280 |  | 289 |  | 153 |  | 172 |  | 127 |  | 117
Wholesale | 59 |  | 68 |  | 21 |  | 19 |  | 38 |  | 49
Bulk power and other | 41 |  | 63 |  | 10 |  | 18 |  | 31 |  | 45
Total Electric Utility | 995 |  | 1,039 |  | 551 |  | 596 |  | 444 |  | 443
Gas Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | 23 |  | 28 |  | 14 |  | 14 |  | 9 |  | 14
Retail - commercial | 12 |  | 18 |  | 9 |  | 8 |  | 3 |  | 10
Retail - industrial | 2 |  | 4 |  | 2 |  | 3 |  | — |  | 1
Transportation/other | 10 |  | 12 |  | 6 |  | 8 |  | 4 |  | 4
Total Gas Utility | 47 |  | 62 |  | 31 |  | 33 |  | 16 |  | 29
Other Utility: |  |  |  |  |  |  |  |  |  |  |
Steam | 11 |  | 9 |  | 11 |  | 9 |  | — |  | —
Other utility | 2 |  | 2 |  | 1 |  | 2 |  | 1 |  | —
Total Other Utility | 13 |  | 11 |  | 12 |  | 11 |  | 1 |  | —
Non-Utility and Other: |  |  |  |  |  |  |  |  |  |  |
Travero and other | 22 |  | 23 |  | — |  | — |  | — |  | —
Total Non-Utility and Other | 22 |  | 23 |  | — |  | — |  | — |  | —
Total revenues | $1,077 |  | $1,135 |  | $594 |  | $640 |  | $461 |  | $472

| Alliant Energy |  | IPL |  | WPL
Nine Months Ended September 30 | 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022
Electric Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | $943 |  | $956 |  | $503 |  | $529 |  | $440 |  | $427
Retail - commercial | 627 |  | 628 |  | 399 |  | 411 |  | 228 |  | 217
Retail - industrial | 740 |  | 743 |  | 389 |  | 418 |  | 351 |  | 325
Wholesale | 154 |  | 168 |  | 47 |  | 49 |  | 107 |  | 119
Bulk power and other | 98 |  | 129 |  | 32 |  | 31 |  | 66 |  | 98
Total Electric Utility | 2,562 |  | 2,624 |  | 1,370 |  | 1,438 |  | 1,192 |  | 1,186
Gas Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | 233 |  | 237 |  | 131 |  | 127 |  | 102 |  | 110
Retail - commercial | 122 |  | 127 |  | 65 |  | 62 |  | 57 |  | 65
Retail - industrial | 12 |  | 15 |  | 8 |  | 10 |  | 4 |  | 5
Transportation/other | 33 |  | 39 |  | 20 |  | 25 |  | 13 |  | 14
Total Gas Utility | 400 |  | 418 |  | 224 |  | 224 |  | 176 |  | 194
Other Utility: |  |  |  |  |  |  |  |  |  |  |
Steam | 32 |  | 29 |  | 32 |  | 29 |  | — |  | —
Other utility | 6 |  | 6 |  | 4 |  | 5 |  | 2 |  | 1
Total Other Utility | 38 |  | 35 |  | 36 |  | 34 |  | 2 |  | 1
Non-Utility and Other: |  |  |  |  |  |  |  |  |  |  |
Travero and other | 66 |  | 70 |  | — |  | — |  | — |  | —
Total Non-Utility and Other | 66 |  | 70 |  | — |  | — |  | — |  | —
Total revenues | $3,066 |  | $3,147 |  | $1,630 |  | $1,696 |  | $1,370 |  | $1,381

NOTE 9. INCOME TAXES
Income Tax Rates - Overall effective income tax rates for the three and nine months ended September 30, which were computed by dividing income tax expense (benefit) by income before income taxes, were as follows. The effective income tax rates were different than the federal statutory rate primarily due to state income taxes, production tax credits, amortization of excess deferred taxes and the effect of rate-making on property-related differences.

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| Alliant Energy |  | IPL |  | WPL
| Three Months |  | Nine Months |  | Three Months |  | Nine Months |  | Three Months |  | Nine Months
| 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022
Overall income tax rate | 2% |  | 6% |  | 1% |  | 4% |  | (22%) |  | (12%) |  | (20%) |  | (14%) |  | 16% |  | 15% |  | 15% |  | 17%

Deferred Tax Assets and Liabilities -
Carryforwards - At September 30, 2023, the carryforwards and expiration dates were estimated as follows (in millions):

| Range of Expiration Dates |  | Alliant Energy |  | IPL |  | WPL
State net operating losses | 2025-2043 |  | $431 |  | $6 |  | $1
Federal tax credits | 2031-2043 |  | 737 |  | 520 |  | 208

Iowa Tax Reform - Pursuant to Iowa tax reform enacted in 2022, in September 2023, the Iowa Department of Revenue announced an Iowa corporate income tax rate of 7.1%, effective January 1, 2024. Deferred tax assets and liabilities are measured at the enacted tax rate expected to be applied when temporary differences are to be realized or settled. Given the announcement of the new Iowa corporate income tax rate, Alliant Energy’s and IPL’s deferred tax liabilities were remeasured based upon the new rate effective January 1, 2024, which resulted in a $73 million reduction of Alliant Energy’s and IPL’s tax-related regulatory assets and a corresponding decrease in their deferred tax liabilities in the third quarter of 2023. The reduction in tax-related regulatory assets is expected to provide cost benefits to IPL’s customers in the future. Alliant Energy parent company’s deferred tax assets were remeasured based upon the new rate effective January 1, 2024, which resulted in a charge of $8 million recorded to income tax expense in Alliant Energy’s income statement and an increase in deferred tax liabilities on Alliant Energy’s balance sheet in the third quarter of 2023. Based on the remeasurement of Alliant Energy parent company’s deferred tax assets in the third quarter of 2022 for the Iowa corporate income tax rate of 8.4% effective January 1, 2023, a charge of $8 million was recorded to income tax expense in Alliant Energy’s income statement in the third quarter of 2022. Alliant Energy is currently unable to predict with certainty the timing or amount of any future rate reductions.
NOTE 10. BENEFIT PLANS
NOTE 10(a) Pension and OPEB Plans -
Net Periodic Benefit Costs - The components of net periodic benefit costs for sponsored defined benefit pension and OPEB plans for the three and nine months ended September 30 are included below (in millions). For IPL and WPL, amounts are for their plan participants covered under plans they sponsor, as well as amounts directly assigned to them related to certain participants in the Alliant Energy and Corporate Services sponsored plans.

| Defined Benefit Pension Plans |  | OPEB Plans
| Three Months |  | Nine Months |  | Three Months |  | Nine Months
Alliant Energy | 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022
Service cost | $2 |  | $3 |  | $4 |  | $7 |  | $1 |  | $— |  | $2 |  | $2
Interest cost | 12 |  | 9 |  | 35 |  | 27 |  | 3 |  | 1 |  | 7 |  | 4
Expected return on plan assets | (14) |  | (18) |  | (40) |  | (52) |  | (2) |  | — |  | (4) |  | (3)
Amortization of prior service credit | (1) |  | — |  | (1) |  | — |  | — |  | — |  | — |  | —
Amortization of actuarial loss | 7 |  | 8 |  | 21 |  | 24 |  | — |  | 1 |  | 1 |  | 2
| $6 |  | $2 |  | $19 |  | $6 |  | $2 |  | $2 |  | $6 |  | $5

| Defined Benefit Pension Plans |  | OPEB Plans
| Three Months |  | Nine Months |  | Three Months |  | Nine Months
IPL | 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022
Service cost | $— |  | $1 |  | $2 |  | $4 |  | $— |  | $— |  | $— |  | $1
Interest cost | 6 |  | 4 |  | 16 |  | 12 |  | 1 |  | 1 |  | 3 |  | 2
Expected return on plan assets | (6) |  | (7) |  | (19) |  | (23) |  | (1) |  | (1) |  | (3) |  | (3)
Amortization of actuarial loss | 2 |  | 3 |  | 8 |  | 10 |  | — |  | — |  | 1 |  | —
| $2 |  | $1 |  | $7 |  | $3 |  | $— |  | $— |  | $1 |  | $—

| Defined Benefit Pension Plans |  | OPEB Plans
| Three Months |  | Nine Months |  | Three Months |  | Nine Months
WPL | 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022
Service cost | $— |  | $— |  | $1 |  | $2 |  | $1 |  | $— |  | $1 |  | $—
Interest cost | 5 |  | 4 |  | 15 |  | 12 |  | 1 |  | 1 |  | 3 |  | 2
Expected return on plan assets | (5) |  | (7) |  | (16) |  | (23) |  | (1) |  | — |  | (1) |  | —
Amortization of actuarial loss | 3 |  | 4 |  | 10 |  | 12 |  | — |  | — |  | — |  | 1
| $3 |  | $1 |  | $10 |  | $3 |  | $1 |  | $1 |  | $3 |  | $3

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NOTE 10(b) Equity-based Compensation Plans - A summary of compensation expense, including amounts allocated to IPL and WPL, and the related income tax benefits recognized for share-based compensation awards for the three and nine months ended September 30 was as follows (in millions):

| Alliant Energy |  | IPL |  | WPL
| Three Months |  | Nine Months |  | Three Months |  | Nine Months |  | Three Months |  | Nine Months
| 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022
Compensation expense | $4 |  | $3 |  | $10 |  | $9 |  | $2 |  | $2 |  | $5 |  | $5 |  | $2 |  | $1 |  | $4 |  | $4
Income tax benefits | 1 |  | 1 |  | 3 |  | 3 |  | 1 |  | — |  | 1 |  | 1 |  | — |  | — |  | 1 |  | 1

As of September 30, 2023, Alliant Energy’s, IPL’s and WPL’s total unrecognized compensation cost related to share-based compensation awards was $11 million, $6 million and $5 million, respectively, which is expected to be recognized over a weighted average period of between 1 year and 2 years.
For the nine months ended September 30, 2023, performance shares, performance restricted stock units and restricted stock units were granted to key employees under existing plans as follows. These shares and units will be paid out in shares of common stock, and are therefore accounted for as equity awards.

|  |  | Weighted Average
| Grants |  | Grant Date Fair Value
Performance shares | 108,513 |  | $55.68
Performance restricted stock units | 123,990 |  | 52.71
Restricted stock units | 105,982 |  | 52.77

As of September 30, 2023, 274,960 shares were included in the calculation of diluted EPS related to the nonvested equity awards.
NOTE 11. DERIVATIVE INSTRUMENTS
Commodity Derivatives -
Notional Amounts - As of September 30, 2023, gross notional amounts and settlement/delivery years related to outstanding swap contracts, option contracts, physical forward contracts and FTRs that were accounted for as commodity derivative instruments were as follows (units in thousands):

| Electricity |  | FTRs |  | Natural Gas |  | Coal |  |
| MWhs |  | Years |  | MWhs |  | Years |  | Dths |  | Years |  | Tons |  | Years |  |  |  |
Alliant Energy | 1,661 |  | 2023-2026 |  | 18,122 |  |  | 2023-2024 |  | 180,519 |  |  | 2023-2032 |  | 370 |  |  | 2023 |  |  |  |
IPL | 746 |  | 2023-2026 |  | 8,078 |  |  | 2023-2024 |  | 85,457 |  |  | 2023-2030 |  | 217 |  |  | 2023 |  |  |  |
WPL | 915 |  | 2023-2026 |  | 10,044 |  |  | 2023-2024 |  | 95,062 |  |  | 2023-2032 |  | 153 |  |  | 2023 |  |  |  |

Financial Statement Presentation - Derivative instruments are recorded at fair value each reporting date on the balance sheets as assets or liabilities as follows (in millions):

| Alliant Energy |  | IPL |  | WPL
| September 30, 2023 |  | December 31, 2022 |  | September 30, 2023 |  | December 31, 2022 |  | September 30, 2023 |  | December 31, 2022
Current derivative assets | $67 |  | $111 |  | $51 |  | $69 |  | $16 |  | $42
Non-current derivative assets | 62 |  | 126 |  | 34 |  | 69 |  | 28 |  | 57
Current derivative liabilities | 32 |  | 59 |  | 15 |  | 40 |  | 17 |  | 19
Non-current derivative liabilities | 34 |  | 20 |  | 6 |  | 6 |  | 28 |  | 14

During the nine months ended September 30, 2023, Alliant Energy’s, IPL’s and WPL’s derivative assets decreased primarily due to settlements of natural gas, FTR and electricity contracts and lower natural gas prices, partially offset by new FTRs resulting from the annual FTR auction in the second quarter of 2023 operated by MISO. Alliant Energy’s and IPL’s derivative liabilities decreased primarily due to settlement of natural gas contracts. Based on IPL’s and WPL’s cost recovery mechanisms, the changes in the fair value of derivative liabilities/assets resulted in comparable changes to regulatory assets/liabilities on the balance sheets.
Credit Risk-related Contingent Features - Various agreements contain credit risk-related contingent features, including requirements to maintain certain credit ratings and/or limitations on liability positions under the agreements based on credit ratings. Certain of these agreements with credit risk-related contingency features are accounted for as derivative instruments. In the event of a material change in creditworthiness or if liability positions exceed certain contractual limits, credit support may need to be provided up to the amount of exposure under the contracts, or the contracts may need to be unwound and underlying liability positions paid. At September 30, 2023 and December 31, 2022, the aggregate fair value of all derivative instruments with credit risk-related contingent features in a net liability position was not materially different than amounts that

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would be required to be posted as credit support to counterparties by Alliant Energy, IPL or WPL if the most restrictive credit risk-related contingent features for derivative agreements in a net liability position were triggered.
Balance Sheet Offsetting - The fair value amounts of derivative instruments subject to a master netting arrangement are not netted by counterparty on the balance sheets. However, if the fair value amounts of derivative instruments by counterparty were netted, derivative assets and derivative liabilities related to commodity contracts would have been presented on the balance sheets as follows (in millions):

| Alliant Energy |  | IPL |  | WPL
| Gross |  |  |  | Gross |  |  |  | Gross |  |
| (as reported) |  | Net |  | (as reported) |  | Net |  | (as reported) |  | Net
September 30, 2023 |  |  |  |  |  |  |  |  |  |  |
Derivative assets | $129 |  | $108 |  | $85 |  | $73 |  | $44 |  | $35
Derivative liabilities | 66 |  | 45 |  | 21 |  | 9 |  | 45 |  | 36
December 31, 2022 |  |  |  |  |  |  |  |  |  |  |
Derivative assets | 237 |  | 193 |  | 138 |  | 108 |  | 99 |  | 85
Derivative liabilities | 79 |  | 35 |  | 46 |  | 16 |  | 33 |  | 19

Fair value amounts recognized for the right to reclaim cash collateral (receivable) or the obligation to return cash collateral (payable) are not offset against fair value amounts recognized for derivative instruments executed with the same counterparty under the same master netting arrangement.
Interest Rate Derivative - In January 2023, AEF entered into a $300 million interest rate swap maturing in January 2026 to mitigate interest rate risk. Under the terms of the swap, AEF exchanged a variable interest rate for a fixed interest rate of 3.93% on a portion of its variable-rate term loan borrowings. The related interest rate derivative was valued based on quoted prices that utilize current market interest rate forecasts. As of September 30, 2023, $6 million of non-current interest rate derivative assets was recorded in “Deferred charges and other” on Alliant Energy’s balance sheet. This interest rate derivative was designated as a cash flow hedge, with changes in fair value recorded as other comprehensive income/loss. As of September 30, 2023, accumulated other comprehensive income included $4 million of income related to the interest rate swap. For the three and nine months ended September 30, 2023, $1 million and $2 million, respectively, of reductions to interest expense were recorded in Alliant Energy’s income statement related to the interest rate swap.
NOTE 12. FAIR VALUE MEASUREMENTS
Fair Value of Financial Instruments - The carrying amounts of current assets and current liabilities approximate fair value because of the short maturity of such financial instruments. Carrying amounts and related estimated fair values of other financial instruments were as follows (in millions):

Alliant Energy | September 30, 2023 |  | December 31, 2022
|  |  | Fair Value |  |  |  | Fair Value
| Carrying |  | Level |  | Level |  | Level |  |  |  | Carrying |  | Level |  | Level |  | Level |  |
| Amount |  | 1 |  | 2 |  | 3 |  | Total |  | Amount |  | 1 |  | 2 |  | 3 |  | Total
Assets: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Money market fund investments | $189 |  |  | $189 |  |  | $— |  |  | $— |  |  | $189 |  |  | $10 |  |  | $10 |  |  | $— |  |  | $— |  |  | $10 |
Commodity derivatives | 129 |  |  | — |  |  | 80 |  |  | 49 |  |  | 129 |  |  | 237 |  |  | — |  |  | 206 |  |  | 31 |  |  | 237 |
Interest rate derivatives | 6 |  |  | — |  |  | 6 |  |  | — |  |  | 6 |  |  | — |  |  | — |  |  | — |  |  | — |  |  | — |
Deferred proceeds | 236 |  |  | — |  |  | — |  |  | 236 |  |  | 236 |  |  | 185 |  |  | — |  |  | — |  |  | 185 |  |  | 185 |
Liabilities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Commodity derivatives | 66 |  |  | — |  |  | 60 |  |  | 6 |  |  | 66 |  |  | 79 |  |  | — |  |  | 67 |  |  | 12 |  |  | 79 |
Long-term debt (incl. current maturities) | 8,838 |  |  | — |  |  | 7,863 |  |  | — |  |  | 7,863 |  |  | 8,076 |  |  | — |  |  | 7,338 |  |  | 1 |  |  | 7,339 |

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IPL | September 30, 2023 |  | December 31, 2022
|  |  | Fair Value |  |  |  | Fair Value
| Carrying |  | Level |  | Level |  | Level |  |  |  | Carrying |  | Level |  | Level |  | Level |  |
| Amount |  | 1 |  | 2 |  | 3 |  | Total |  | Amount |  | 1 |  | 2 |  | 3 |  | Total
Assets: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Money market fund investments | $180 |  |  | $180 |  |  | $— |  |  | $— |  |  | $180 |  |  | $10 |  |  | $10 |  |  | $— |  |  | $— |  |  | $10 |
Commodity derivatives | 85 |  |  | — |  |  | 45 |  |  | 40 |  |  | 85 |  |  | 138 |  |  | — |  |  | 111 |  |  | 27 |  |  | 138 |
Deferred proceeds | 236 |  |  | — |  |  | — |  |  | 236 |  |  | 236 |  |  | 185 |  |  | — |  |  | — |  |  | 185 |  |  | 185 |
Liabilities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Commodity derivatives | 21 |  |  | — |  |  | 16 |  |  | 5 |  |  | 21 |  |  | 46 |  |  | — |  |  | 35 |  |  | 11 |  |  | 46 |
Long-term debt | 3,944 |  |  | — |  |  | 3,422 |  |  | — |  |  | 3,422 |  |  | 3,646 |  |  | — |  |  | 3,228 |  |  | — |  |  | 3,228 |

WPL | September 30, 2023 |  | December 31, 2022
|  |  | Fair Value |  |  |  | Fair Value
| Carrying |  | Level |  | Level |  | Level |  |  |  | Carrying |  | Level |  | Level |  | Level |  |
| Amount |  | 1 |  | 2 |  | 3 |  | Total |  | Amount |  | 1 |  | 2 |  | 3 |  | Total
Assets: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Commodity derivatives | $44 |  |  | $— |  |  | $35 |  |  | $9 |  |  | $44 |  |  | $99 |  |  | $— |  |  | $95 |  |  | $4 |  |  | $99 |
Liabilities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Commodity derivatives | 45 |  |  | — |  |  | 44 |  |  | 1 |  |  | 45 |  |  | 33 |  |  | — |  |  | 32 |  |  | 1 |  |  | 33 |
Long-term debt | 3,069 |  |  | — |  |  | 2,722 |  |  | — |  |  | 2,722 |  |  | 2,770 |  |  | — |  |  | 2,542 |  |  | — |  |  | 2,542 |

Information for fair value measurements using significant unobservable inputs (Level 3 inputs) was as follows (in millions):

Alliant Energy | Commodity Contract Derivative |  |
| Assets and (Liabilities), net |  | Deferred Proceeds
Three Months Ended September 30 | 2023 |  | 2022 |  | 2023 |  | 2022
Beginning balance, July 1 | $54 |  | $72 |  | $175 |  | $244
Total net gains (losses) included in changes in net assets (realized/unrealized) | 17 |  | (1) |  | — |  | —
Sales | (1) |  | — |  | — |  | —
Settlements (a) | (27) |  | (26) |  | 61 |  | 4
Ending balance, September 30 | $43 |  | $45 |  | $236 |  | $248
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 | $17 |  | ($1) |  | $— |  | $—

Alliant Energy | Commodity Contract Derivative |  |
| Assets and (Liabilities), net |  | Deferred Proceeds
Nine Months Ended September 30 | 2023 |  | 2022 |  | 2023 |  | 2022
Beginning balance, January 1 | $19 |  | $29 |  | $185 |  | $214
Total net gains (losses) included in changes in net assets (realized/unrealized) | 6 |  | (17) |  | — |  | —
Purchases | 62 |  | 79 |  | — |  | —
Sales | (2) |  | — |  | — |  | —
Settlements (a) | (42) |  | (46) |  | 51 |  | 34
Ending balance, September 30 | $43 |  | $45 |  | $236 |  | $248
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 | $6 |  | ($17) |  | $— |  | $—

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IPL | Commodity Contract Derivative |  |
| Assets and (Liabilities), net |  | Deferred Proceeds
Three Months Ended September 30 | 2023 |  | 2022 |  | 2023 |  | 2022
Beginning balance, July 1 | $41 |  | $58 |  | $175 |  | $244
Total net gains (losses) included in changes in net assets (realized/unrealized) | 12 |  | (6) |  | — |  | —
Sales | (1) |  | — |  | — |  | —
Settlements (a) | (17) |  | (19) |  | 61 |  | 4
Ending balance, September 30 | $35 |  | $33 |  | $236 |  | $248
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 | $12 |  | ($6) |  | $— |  | $—

IPL | Commodity Contract Derivative |  |
| Assets and (Liabilities), net |  | Deferred Proceeds
Nine Months Ended September 30 | 2023 |  | 2022 |  | 2023 |  | 2022
Beginning balance, January 1 | $16 |  | $18 |  | $185 |  | $214
Total net losses included in changes in net assets (realized/unrealized) | — |  | (13) |  | — |  | —
Purchases | 51 |  | 58 |  | — |  | —
Sales | (2) |  | — |  | — |  | —
Settlements (a) | (30) |  | (30) |  | 51 |  | 34
Ending balance, September 30 | $35 |  | $33 |  | $236 |  | $248
The amount of total net losses for the period included in changes in net assets attributable to the change in unrealized losses relating to assets and liabilities held at September 30 | $— |  | ($14) |  | $— |  | $—

WPL | Commodity Contract Derivative
| Assets and (Liabilities), net
Three Months Ended September 30 | 2023 |  | 2022
Beginning balance, July 1 | $13 |  | $14
Total net gains included in changes in net assets (realized/unrealized) | 5 |  | 5
Settlements | (10) |  | (7)
Ending balance, September 30 | $8 |  | $12
The amount of total net gains for the period included in changes in net assets attributable to the change in unrealized gains relating to assets and liabilities held at September 30 | $5 |  | $5

WPL | Commodity Contract Derivative
| Assets and (Liabilities), net
Nine Months Ended September 30 | 2023 |  | 2022
Beginning balance, January 1 | $3 |  | $11
Total net gains (losses) included in changes in net assets (realized/unrealized) | 6 |  | (4)
Purchases | 11 |  | 21
Settlements | (12) |  | (16)
Ending balance, September 30 | $8 |  | $12
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 | $6 |  | ($3)

(a)Settlements related to deferred proceeds are due to the change in the carrying amount of receivables sold less the allowance for expected credit losses associated with the receivables sold and cash amounts received from the receivables sold.
Commodity Contracts - The fair value of FTR and natural gas commodity contracts categorized as Level 3 was recognized as net derivative assets (liabilities) as follows (in millions):

| Alliant Energy |  | IPL |  | WPL
| Excluding FTRs |  | FTRs |  | Excluding FTRs |  | FTRs |  | Excluding FTRs |  | FTRs
September 30, 2023 | $3 |  | $40 |  | $4 |  | $31 |  | ($1) |  | $9
December 31, 2022 | (10) |  | 29 |  | (9) |  | 25 |  | (1) |  | 4

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NOTE 13. COMMITMENTS AND CONTINGENCIES
NOTE 13(a) Capital Purchase Commitments - Various contractual obligations contain minimum future commitments related to capital expenditures for certain construction projects, including IPL’s and WPL’s expansion of solar generation. At September 30, 2023, Alliant Energy’s, IPL’s and WPL’s minimum future commitments for these projects were $221 million, $175 million and $46 million, respectively.
NOTE 13(b) Other Purchase Commitments - Various commodity supply, transportation and storage contracts help meet obligations to provide electricity and natural gas to utility customers. In addition, there are various purchase commitments associated with other goods and services. At September 30, 2023, related minimum future commitments were as follows (in millions):

| Alliant Energy |  | IPL |  | WPL
Natural gas | $962 |  | $436 |  | $526
Coal | 188 |  | 108 |  | 80
Other (a) | 125 |  | 52 |  | 25
| $1,275 |  | $596 |  | $631

(a)Includes individual commitments incurred during the normal course of business that exceeded $1 million at September 30, 2023.
NOTE 13(c) Guarantees and Indemnifications -
Whiting Petroleum - Whiting Petroleum is an independent oil and gas company. In 2004, Alliant Energy sold its remaining interest in Whiting Petroleum. Alliant Energy Resources, LLC, as the successor to a predecessor entity that owned Whiting Petroleum, and a wholly-owned subsidiary of AEF, continues to guarantee the partnership obligations of an affiliate of Whiting Petroleum under multiple general partnership agreements in the oil and gas industry. The guarantees do not include a maximum limit. Based on information made available to Alliant Energy by Whiting Petroleum, the Whiting Petroleum affiliate holds an approximate 6% share in the partnerships, and currently known obligations include costs associated with the future abandonment of certain facilities owned by the partnerships. The general partnerships were formed under California law, and Alliant Energy Resources, LLC may need to perform under the guarantees if the affiliate of Whiting Petroleum is unable to meet its partnership obligations.
As of September 30, 2023, the currently known partnership obligations for the abandonment obligations are estimated at $58 million, which represents Alliant Energy’s currently estimated maximum exposure under the guarantees. Alliant Energy estimates its expected loss to be a portion of the $58 million of known partnership abandonment obligations of the Whiting Petroleum affiliate and the other partners. Alliant Energy is not aware of any material liabilities related to these guarantees that it is probable that it will be obligated to pay; however, as of both September 30, 2023 and December 31, 2022, a liability of $5 million is recorded in “Other liabilities” on Alliant Energy’s balance sheets for expected credit losses related to the contingent obligations that are in the scope of these guarantees.
Whiting Petroleum completed a business combination with Oasis Petroleum Inc. in July 2022. The combined operations are now known as Chord Energy Corporation. The business combination is not expected to affect the scope of the Whiting Petroleum affiliate’s obligations to Alliant Energy or Alliant Energy’s related guarantees.
Non-utility Wind Farm in Oklahoma - In 2017, a wholly-owned subsidiary of AEF acquired a cash equity ownership interest in a non-utility wind farm located in Oklahoma. The wind farm provides electricity to a third party under a long-term PPA. Alliant Energy provided a parent guarantee of its subsidiary’s indemnification obligations under the related operating agreement and PPA. Alliant Energy’s obligations under the operating agreement were $51 million as of September 30, 2023 and will reduce annually until expiring in July 2047. Alliant Energy’s obligations under the PPA are subject to a maximum limit of $17 million and expire in December 2031, subject to potential extension. Alliant Energy is not aware of any material liabilities related to this guarantee that it is probable that it will be obligated to pay and therefore has not recognized any material liabilities related to this guarantee as of September 30, 2023 and December 31, 2022.
NOTE 13(d) Environmental Matters -
Manufactured Gas Plant (MGP) Sites - IPL and WPL have current or previous ownership interests in various sites that are previously associated with the production of gas for which IPL and WPL have, or may have in the future, liability for investigation, remediation and monitoring costs. IPL and WPL are working pursuant to the requirements of various federal and state agencies to investigate, mitigate, prevent and remediate, where necessary, the environmental impacts to property, including natural resources, at and around these former MGP sites in order to protect public health and the environment. At September 30, 2023, estimated future costs expected to be incurred for the investigation, remediation and monitoring of the MGP sites, as well as environmental liabilities recorded on the balance sheets for these sites, which are not discounted, were as follows (in millions):

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| Alliant Energy |  | IPL |  | WPL
Range of estimated future costs | $9 |  | - | $36 |  | $5 |  | - | $11 |  | $4 |  | - | $25
Current and non-current environmental liabilities | $18 |  | $8 |  | $10

IPL Consent Decree - In 2015, the U.S. District Court for the Northern District of Iowa approved a Consent Decree that IPL entered into with the EPA, the Sierra Club, the State of Iowa and Linn County in Iowa, thereby resolving potential Clean Air Act issues associated with emissions from IPL’s coal-fired generating facilities in Iowa. IPL has completed various requirements under the Consent Decree. IPL’s remaining requirements include fuel switching or retiring Prairie Creek Units 1 and 3 by December 31, 2025. Alliant Energy and IPL currently expect to recover material costs incurred by IPL related to compliance with the terms of the Consent Decree from IPL’s electric customers.
Other Environmental Contingencies - In addition to the environmental liabilities discussed above, various environmental rules are monitored that may have a significant impact on future operations. Several of these environmental rules are subject to legal challenges, reconsideration and/or other uncertainties. Given uncertainties regarding the outcome, timing and compliance plans for these environmental matters, the complete financial impact of each of these rules is not able to be determined; however, future capital investments and/or modifications to EGUs and electric and gas distribution systems to comply with certain of these rules could be significant. Specific current, proposed or potential environmental matters include, among others: Cross-State Air Pollution Rule, Effluent Limitation Guidelines, Coal Combustion Residuals Rule, and various legislation and EPA regulations to monitor and regulate the emission of greenhouse gases, including the Clean Air Act.
NOTE 13(e) MISO Transmission Owner Return on Equity Complaints - A group of stakeholders, including MISO cooperative and municipal utilities, previously filed complaints with the Federal Energy Regulatory Commission (FERC) requesting a reduction to the base return on equity authorized for MISO transmission owners, including ITC Midwest LLC and ATC. In 2019, FERC issued an order on the previously filed complaints and reduced the base return on equity authorized for the MISO transmission owners to 9.88% for November 12, 2013 through February 11, 2015, and subsequent to September 28, 2016. In 2020, FERC issued orders in response to various rehearing requests and increased the base return on equity authorized for the MISO transmission owners from 9.88% to 10.02% for November 12, 2013 through February 11, 2015, and subsequent to September 28, 2016. In August 2022, the U.S. Court of Appeals for the District of Columbia Circuit vacated FERC’s prior orders that established the base return on equity authorized for the MISO transmission owners and remanded the cases to FERC for further proceedings, which may result in additional changes to the base return on equity authorized for the MISO transmission owners. Any further changes in FERC’s decisions may have an impact on Alliant Energy’s share of ATC’s future earnings and customer costs.
NOTE 14. SEGMENTS OF BUSINESS
Certain financial information relating to Alliant Energy’s, IPL’s and WPL’s business segments is as follows. Intersegment revenues were not material to their respective operations.

Alliant Energy |  |  |  |  |  |  |  |  | ATC Holdings, |  | Alliant
| Utility |  | Non-Utility, |  | Energy
| Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
| (in millions)
Three Months Ended September 30, 2023 |  |  |  |  |  |  |  |  |  |  |
Revenues | $995 |  | $47 |  | $13 |  | $1,055 |  | $22 |  | $1,077
Operating income (loss) | 319 |  | (4) |  | — |  | 315 |  | 7 |  | 322
Net income (loss) attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 277 |  | (18) |  | 259
Three Months Ended September 30, 2022 |  |  |  |  |  |  |  |  |  |  |
Revenues | $1,039 |  | $62 |  | $11 |  | $1,112 |  | $23 |  | $1,135
Operating income (loss) | 304 |  | (3) |  | 1 |  | 302 |  | 7 |  | 309
Net income (loss) attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 245 |  | (18) |  | 227

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Alliant Energy |  |  |  |  |  |  |  |  | ATC Holdings, |  | Alliant
| Utility |  | Non-Utility, |  | Energy
| Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
| (in millions)
Nine Months Ended September 30, 2023 |  |  |  |  |  |  |  |  |  |  |
Revenues | $2,562 |  | $400 |  | $38 |  | $3,000 |  | $66 |  | $3,066
Operating income | 682 |  | 48 |  | 12 |  | 742 |  | 18 |  | 760
Net income (loss) attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 598 |  | (16) |  | 582
Nine Months Ended September 30, 2022 |  |  |  |  |  |  |  |  |  |  |
Revenues | $2,624 |  | $418 |  | $35 |  | $3,077 |  | $70 |  | $3,147
Operating income | 680 |  | 62 |  | 4 |  | 746 |  | 23 |  | 769
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 574 |  | 5 |  | 579

IPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended September 30, 2023 |  |  |  |  |  |  |
Revenues | $551 |  | $31 |  | $12 |  | $594
Operating income (loss) | 171 |  | (2) |  | 4 |  | 173
Net income |  |  |  |  |  |  | 170
Three Months Ended September 30, 2022 |  |  |  |  |  |  |
Revenues | $596 |  | $33 |  | $11 |  | $640
Operating income (loss) | 174 |  | (3) |  | — |  | 171
Net income |  |  |  |  |  |  | 154
Nine Months Ended September 30, 2023 |  |  |  |  |  |  |
Revenues | $1,370 |  | $224 |  | $36 |  | $1,630
Operating income | 342 |  | 25 |  | 12 |  | 379
Net income |  |  |  |  |  |  | 331
Nine Months Ended September 30, 2022 |  |  |  |  |  |  |
Revenues | $1,438 |  | $224 |  | $34 |  | $1,696
Operating income | 353 |  | 33 |  | 3 |  | 389
Net income |  |  |  |  |  |  | 327

WPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended September 30, 2023 |  |  |  |  |  |  |
Revenues | $444 |  | $16 |  | $1 |  | $461
Operating income (loss) | 148 |  | (2) |  | (4) |  | 142
Net income |  |  |  |  |  |  | 107
Three Months Ended September 30, 2022 |  |  |  |  |  |  |
Revenues | $443 |  | $29 |  | $— |  | $472
Operating income | 130 |  | — |  | 1 |  | 131
Net income |  |  |  |  |  |  | 91
Nine Months Ended September 30, 2023 |  |  |  |  |  |  |
Revenues | $1,192 |  | $176 |  | $2 |  | $1,370
Operating income | 340 |  | 23 |  | — |  | 363
Net income |  |  |  |  |  |  | 267
Nine Months Ended September 30, 2022 |  |  |  |  |  |  |
Revenues | $1,186 |  | $194 |  | $1 |  | $1,381
Operating income | 327 |  | 29 |  | 1 |  | 357
Net income |  |  |  |  |  |  | 247

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NOTE 15. RELATED PARTIES
Service Agreements - Pursuant to service agreements, IPL and WPL receive various administrative and general services from an affiliate, Corporate Services. These services are billed to IPL and WPL at cost based on expenses incurred by Corporate Services for the benefit of IPL and WPL, respectively. These costs consisted primarily of employee compensation and benefits, fees associated with various professional services, depreciation and amortization of property, plant and equipment, and a return on net assets. Corporate Services also acts as agent on behalf of IPL and WPL pursuant to the service agreements. As agent, Corporate Services enters into energy, capacity, ancillary services, and transmission sale and purchase transactions within MISO. Corporate Services assigns such sales and purchases among IPL and WPL based on statements received from MISO. The amounts billed for services provided, sales credited and purchases for the three and nine months ended September 30 were as follows (in millions):

| IPL |  | WPL
| Three Months |  | Nine Months |  | Three Months |  | Nine Months
| 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022
Corporate Services billings | $46 |  | $45 |  | $134 |  | $136 |  | $40 |  | $39 |  | $120 |  | $117
Sales credited | 3 |  | 11 |  | 11 |  | 11 |  | 23 |  | 31 |  | 45 |  | 62
Purchases billed | 133 |  | 119 |  | 320 |  | 342 |  | 5 |  | 42 |  | 21 |  | 103

Net intercompany payables to Corporate Services were as follows (in millions):

| IPL |  | WPL
| September 30, 2023 |  | December 31, 2022 |  | September 30, 2023 |  | December 31, 2022
Net payables to Corporate Services | $136 |  | $103 |  | $71 |  | $56

ATC - Pursuant to various agreements, WPL receives a range of transmission services from ATC. WPL provides operation, maintenance, and construction services to ATC. WPL and ATC also bill each other for use of shared facilities owned by each party. The related amounts billed between the parties for the three and nine months ended September 30 were as follows (in millions):

| Three Months |  | Nine Months
| 2023 |  | 2022 |  | 2023 |  | 2022
ATC billings to WPL | $41 |  | $38 |  | $119 |  | $107
WPL billings to ATC | 5 |  | 6 |  | 16 |  | 14

WPL owed ATC net amounts of $9 million as of September 30, 2023 and $10 million as of December 31, 2022.
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 2022 Form 10-K. Unless otherwise noted, all “per share” references in MDA refer to earnings per diluted share.

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2023 HIGHLIGHTS
Key highlights since the filing of the 2022 Form 10-K include the following:
Customer Investments:
•In 2021, IPL filed for advance rate-making principles with the IUB for up to 400 MW of solar generation and 75 MW of battery storage. In April 2023, the IUB approved advance rate-making principles for up to 200 MW of solar generation. The IUB’s order included a cost target of $1,575/kilowatt, including AFUDC and transmission upgrade costs among other costs. In May 2023, IPL requested reconsideration of certain ratemaking principles for the up to 200 MW of solar generation, including the cost target and return on common equity. In June 2023, IPL and the IUB filed a joint motion for remand of the other 200 MW of solar generation and 75 MW of battery storage for further reconsideration by the IUB, which was granted by the court. In June 2023, the IUB granted reconsideration of advance rate-making principles for the 400 MW of solar generation and 75 MW of battery storage. In October 2023, the IUB issued an order approving a modified non-unanimous settlement agreement with the Iowa Office of Consumer Advocate among other stakeholders, for up to 400 MW of solar generation, subject to a cost target of $1,650/kilowatt, including AFUDC and transmission upgrade costs among other costs, and a related return on common equity of no less than 10.25% with the opportunity to request a higher return on common equity in future IPL retail electric rate review filings. Any reasonable and prudent costs incurred in excess of the cost target are eligible for recovery at the return on common equity determined in IPL retail electric rate review filings. The IUB’s order also included a consumer protection plan, which monitors IPL’s achievement of certain aggregate summer capacity factors for the up to 400 MW of solar generation projects during June, July and August each calendar year over 30 years. Actual three-year rolling average summer capacity factors will be compared to target capacity factors, which may result in surpluses or deficits that would be offset against one another and contribute to an accumulated balance in a given calendar year. Surpluses or deficits will be capped at $3 million in aggregate per year. At the end of the program, any accumulated deficit balance would be addressed in IPL’s next rate review, and any accumulated surplus balance would not result in any return to IPL. In November 2023, IPL accepted these advance rate-making principles.
•In October 2023, WPL received an oral decision from the PSCW authorizing WPL to construct, own and operate approximately 99 MW of battery storage at the Edgewater Generating Station.
•In August 2023, WPL received an order from the PSCW authorizing WPL to construct, own and operate 175 MW of battery storage, with 100 MW and 75 MW at the Grant County and Wood County solar projects, respectively.
•In June 2023, WPL filed requests with the PSCW for approval to construct improvements at the natural gas-fired Neenah Energy Facility and Sheboygan Falls Energy Facility, which would increase the capacity and efficiency of the EGUs. A decision from the PSCW is currently expected by the second quarter of 2024.
•In April 2023, the IUB issued a certificate of public convenience, use and necessity (GCU Certificate) granting IPL approval to construct, own and operate up to 150 MW of solar generation and up to 75 MW of battery storage at the Wever project in Lee County, Iowa. In March 2023, the IUB issued a GCU Certificate granting IPL approval to construct, own and operate up to 50 MW of solar generation and up to 25 MW of battery storage at the Creston project in Union County, Iowa. These solar projects are included in the IUB’s October 2023 order approving advance rate-making principles for up to 400 MW of solar generation.
Rate Matters:
•In April 2023, WPL filed a retail electric and gas rate review with the PSCW for the 2024/2025 forward-looking Test Period. The key drivers for the filing include revenue requirement impacts of increasing electric and gas rate base, including investments in solar generation and battery storage. The filing requested approval for WPL to implement increases in annual rates for its retail electric and gas customers of $111 million and $17 million in 2024, respectively, with any granted rate changes expected to be effective on January 1, 2024. WPL’s filing also requested approval to implement an additional $71 million increase in annual rates for its retail electric customers in 2025, with any granted rate changes expected to be effective on January 1, 2025. WPL also requested to maintain its current authorized return on common equity of 10% and implement an approximate 56% common equity component of its regulatory capital structure, as well as receive continued recovery of and a return on the remaining net book value of Edgewater Unit 5, which is currently expected to be retired by June 1, 2025. A decision from the PSCW is currently expected by the end of 2023.
•In October 2023, IPL filed a retail electric and gas rate review with the IUB for the October 2024 through September 2025 forward-looking Test Period. The key drivers for the filing include revenue requirement impacts of increasing electric and gas rate base, including investments in solar generation and repowering of the existing Franklin County wind farm. The filing requested approval for IPL to implement increases in annual rates for its retail electric and gas customers of $160 million and $14 million, respectively, with any granted rate changes expected to be effective on October 1, 2024. IPL’s filing also requested approval to implement an additional $124 million increase in annual rates for its retail electric customers in 2025, with any granted rate changes expected to be effective on October 1, 2025. IPL also requested a return on common equity of 10% and a 52% common equity component of its regulatory capital structure, as well as to receive continued recovery of and a return on the remaining net book value of the Lansing Generating Station through 2037, which was retired in May 2023. A decision from the IUB is currently expected by the third quarter of 2024.
•In August 2023, the PSCW authorized WPL to collect $117 million in higher rates, plus interest, from its retail electric customers from October 2023 through December 2025 for fuel-related costs incurred by WPL in 2022 that were higher than fuel-related costs used to determine rates for such period.

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Legislative Matters:
•Refer to Note 9 for discussion of the Iowa corporate income tax rate that will be effective January 1, 2024, pursuant to Iowa tax reform enacted in 2022.
Financings and Common Stock Dividends:
•Refer to “Results of Operations” for discussion of expected future issuances of common stock and common stock dividends, and expected future issuances and retirements of long-term debt, by the end of 2024.
RESULTS OF OPERATIONS
Results of operations include financial information prepared in accordance with GAAP as well as utility electric margins and utility gas margins, which are not measures of financial performance under GAAP. Utility electric margins are defined as electric revenues less electric production fuel, purchased power and electric transmission service expenses. Utility gas margins are defined as gas revenues less cost of gas sold. Utility electric margins and utility gas margins are non-GAAP financial measures because they exclude other utility and non-utility revenues, other operation and maintenance expenses, depreciation and amortization expenses, and taxes other than income tax expense.
Management believes that utility electric and gas margins provide a meaningful basis for evaluating and managing utility operations since electric production fuel, purchased power and electric transmission service expenses and cost of gas sold are generally passed through to customers, and therefore, result in changes to electric and gas revenues that are comparable to changes in such expenses. The presentation of utility electric and gas margins herein is intended to provide supplemental information for investors regarding operating performance. These utility electric and gas margins may not be comparable to how other entities define utility electric and gas margin. Furthermore, these measures are not intended to replace operating income as determined in accordance with GAAP as an indicator of operating performance.
Additionally, the table below includes 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 segment 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.
Financial Results Overview - 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):

| 2023 |  | 2022 |
| Income (Loss) |  | EPS |  | Income (Loss) |  | EPS |
Utilities and Corporate Services | $281 |  | $1.11 |  | $249 |  | $0.99 |
ATC Holdings | 9 |  | 0.03 |  | 5 |  | 0.02 |
Non-utility and Parent | (31) |  | (0.12) |  | (27) |  | (0.11) |
Alliant Energy Consolidated | $259 |  | $1.02 |  | $227 |  | $0.90 |

Alliant Energy’s Utilities and Corporate Services net income increased by $32 million for the three-month period, primarily due to higher revenue requirements and AFUDC from WPL’s capital investments, and lower other operation and maintenance expenses. These items were partially offset by higher interest expense.
Alliant Energy’s Non-utility and Parent net income decreased by $4 million for the three-month period, primarily due to higher interest expense.

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For the three and nine months ended September 30, operating income and a reconciliation of utility electric and gas margins to the most directly comparable GAAP measure, operating income, was as follows (in millions):

| Alliant Energy |  | IPL |  | WPL
Three Months | 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022
Operating income | $322 |  | $309 |  | $173 |  | $171 |  | $142 |  | $131
Electric utility revenues | $995 |  | $1,039 |  | $551 |  | $596 |  | $444 |  | $443
Electric production fuel and purchased power expenses | (231) |  | (274) |  | (99) |  | (140) |  | (132) |  | (134)
Electric transmission service expense | (154) |  | (157) |  | (115) |  | (115) |  | (39) |  | (42)
Utility Electric Margin (non-GAAP) | 610 |  | 608 |  | 337 |  | 341 |  | 273 |  | 267
Gas utility revenues | 47 |  | 62 |  | 31 |  | 33 |  | 16 |  | 29
Cost of gas sold expense | (12) |  | (26) |  | (12) |  | (14) |  | — |  | (13)
Utility Gas Margin (non-GAAP) | 35 |  | 36 |  | 19 |  | 19 |  | 16 |  | 16
Other utility revenues | 13 |  | 11 |  | 12 |  | 11 |  | 1 |  | —
Non-utility revenues | 22 |  | 23 |  | — |  | — |  | — |  | —
Other operation and maintenance expenses | (160) |  | (172) |  | (84) |  | (90) |  | (64) |  | (70)
Depreciation and amortization expenses | (170) |  | (169) |  | (97) |  | (95) |  | (71) |  | (71)
Taxes other than income taxes expense | (28) |  | (28) |  | (14) |  | (15) |  | (13) |  | (11)
Operating income | $322 |  | $309 |  | $173 |  | $171 |  | $142 |  | $131

| Alliant Energy |  | IPL |  | WPL
Nine Months | 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022
Operating income | $760 |  | $769 |  | $379 |  | $389 |  | $363 |  | $357
Electric utility revenues | $2,562 |  | $2,624 |  | $1,370 |  | $1,438 |  | $1,192 |  | $1,186
Electric production fuel and purchased power expenses | (553) |  | (633) |  | (213) |  | (290) |  | (341) |  | (343)
Electric transmission service expense | (438) |  | (428) |  | (316) |  | (303) |  | (122) |  | (125)
Utility Electric Margin (non-GAAP) | 1,571 |  | 1,563 |  | 841 |  | 845 |  | 729 |  | 718
Gas utility revenues | 400 |  | 418 |  | 224 |  | 224 |  | 176 |  | 194
Cost of gas sold expense | (226) |  | (242) |  | (127) |  | (126) |  | (99) |  | (117)
Utility Gas Margin (non-GAAP) | 174 |  | 176 |  | 97 |  | 98 |  | 77 |  | 77
Other utility revenues | 38 |  | 35 |  | 36 |  | 34 |  | 2 |  | 1
Non-utility revenues | 66 |  | 70 |  | — |  | — |  | — |  | —
Other operation and maintenance expenses | (499) |  | (492) |  | (264) |  | (260) |  | (197) |  | (193)
Depreciation and amortization expenses | (503) |  | (501) |  | (288) |  | (285) |  | (208) |  | (211)
Taxes other than income taxes expense | (87) |  | (82) |  | (43) |  | (43) |  | (40) |  | (35)
Operating income | $760 |  | $769 |  | $379 |  | $389 |  | $363 |  | $357

Operating Income Variances - Variances between periods in operating income for the three and nine months ended September 30, 2023 compared to the same periods in 2022 were as follows (in millions):

| Three Months |  | Nine Months
| Alliant Energy |  | IPL |  | WPL |  | Alliant Energy |  | IPL |  | WPL
Total higher (lower) utility electric margin variance (Refer to details below) | $2 |  | ($4) |  | $6 |  | $8 |  | ($4) |  | $11
Total lower utility gas margin variance (Refer to details below) | (1) |  | — |  | — |  | (2) |  | (1) |  | —
Total (higher) lower other operation and maintenance expenses variance (Refer to details below) | 12 |  | 6 |  | 6 |  | (7) |  | (4) |  | (4)
Total (higher) lower depreciation and amortization expenses (Refer to Note 2 for discussion of reductions to WPL's depreciation and amortization expense, which was partially offset by WPL's solar generation placed in service in 2022) | (1) |  | (2) |  | — |  | (2) |  | (3) |  | 3
Other | 1 |  | 2 |  | (1) |  | (6) |  | 2 |  | (4)
| $13 |  | $2 |  | $11 |  | ($9) |  | ($10) |  | $6

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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 | Electric |  | Gas
| Revenues |  | MWhs Sold |  | Revenues |  | Dths Sold
| 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022
Three Months |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Retail | $895 |  | $908 |  | 6,821 |  | 6,788 |  | $37 |  | $50 |  | 3,283 |  | 3,584
Sales for resale: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Wholesale | 59 |  | 68 |  | 795 |  | 774 |  | N/A |  | N/A |  | N/A |  | N/A
Bulk power and other | 25 |  | 47 |  | 1,409 |  | 985 |  | N/A |  | N/A |  | N/A |  | N/A
Transportation/Other | 16 |  | 16 |  | 14 |  | 16 |  | 10 |  | 12 |  | 29,776 |  | 30,982
| $995 |  | $1,039 |  | 9,039 |  | 8,563 |  | $47 |  | $62 |  | 33,059 |  | 34,566
Nine Months |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Retail | $2,310 |  | $2,327 |  | 19,005 |  | 19,304 |  | $367 |  | $379 |  | 31,897 |  | 37,284
Sales for resale: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Wholesale | 154 |  | 168 |  | 2,172 |  | 2,172 |  | N/A |  | N/A |  | N/A |  | N/A
Bulk power and other | 62 |  | 83 |  | 3,756 |  | 2,989 |  | N/A |  | N/A |  | N/A |  | N/A
Transportation/Other | 36 |  | 46 |  | 43 |  | 46 |  | 33 |  | 39 |  | 88,167 |  | 83,241
| $2,562 |  | $2,624 |  | 24,976 |  | 24,511 |  | $400 |  | $418 |  | 120,064 |  | 120,525

IPL | Electric |  | Gas
| Revenues |  | MWhs Sold |  | Revenues |  | Dths Sold
| 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022
Three Months |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Retail | $520 |  | $559 |  | 3,736 |  | 3,736 |  | $25 |  | $25 |  | 1,658 |  | 1,739
Sales for resale: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Wholesale | 21 |  | 19 |  | 213 |  | 208 |  | N/A |  | N/A |  | N/A |  | N/A
Bulk power and other | 3 |  | 9 |  | 332 |  | 373 |  | N/A |  | N/A |  | N/A |  | N/A
Transportation/Other | 7 |  | 9 |  | 8 |  | 9 |  | 6 |  | 8 |  | 9,999 |  | 9,743
| $551 |  | $596 |  | 4,289 |  | 4,326 |  | $31 |  | $33 |  | 11,657 |  | 11,482
Nine Months |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Retail | $1,291 |  | $1,358 |  | 10,599 |  | 10,821 |  | $204 |  | $199 |  | 16,065 |  | 19,118
Sales for resale: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Wholesale | 47 |  | 49 |  | 578 |  | 581 |  | N/A |  | N/A |  | N/A |  | N/A
Bulk power and other | 12 |  | 4 |  | 1,188 |  | 1,019 |  | N/A |  | N/A |  | N/A |  | N/A
Transportation/Other | 20 |  | 27 |  | 24 |  | 25 |  | 20 |  | 25 |  | 31,588 |  | 31,917
| $1,370 |  | $1,438 |  | 12,389 |  | 12,446 |  | $224 |  | $224 |  | 47,653 |  | 51,035

WPL | Electric |  | Gas
| Revenues |  | MWhs Sold |  | Revenues |  | Dths Sold
| 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022
Three Months |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Retail | $375 |  | $349 |  | 3,085 |  | 3,052 |  | $12 |  | $25 |  | 1,625 |  | 1,845
Sales for resale: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Wholesale | 38 |  | 49 |  | 582 |  | 566 |  | N/A |  | N/A |  | N/A |  | N/A
Bulk power and other | 22 |  | 38 |  | 1,077 |  | 612 |  | N/A |  | N/A |  | N/A |  | N/A
Transportation/Other | 9 |  | 7 |  | 6 |  | 7 |  | 4 |  | 4 |  | 19,777 |  | 21,239
| $444 |  | $443 |  | 4,750 |  | 4,237 |  | $16 |  | $29 |  | 21,402 |  | 23,084
Nine Months |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Retail | $1,019 |  | $969 |  | 8,406 |  | 8,483 |  | $163 |  | $180 |  | 15,832 |  | 18,166
Sales for resale: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Wholesale | 107 |  | 119 |  | 1,594 |  | 1,591 |  | N/A |  | N/A |  | N/A |  | N/A
Bulk power and other | 50 |  | 79 |  | 2,568 |  | 1,970 |  | N/A |  | N/A |  | N/A |  | N/A
Transportation/Other | 16 |  | 19 |  | 19 |  | 21 |  | 13 |  | 14 |  | 56,579 |  | 51,324
| $1,192 |  | $1,186 |  | 12,587 |  | 12,065 |  | $176 |  | $194 |  | 72,411 |  | 69,490

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Sales Trends and Temperatures - Alliant Energy’s retail electric and gas sales volumes increased 1% and decreased 8%, respectively, for the three months ended September 30, 2023 compared to the same period in 2022, primarily due to changes in temperatures. Alliant Energy’s retail electric and gas sales volumes decreased 2% and 14%, respectively, for the nine months ended September 30, 2023 compared to the same period in 2022, primarily due to changes in temperatures.
Estimated increases (decreases) to electric and gas margins from the impacts of temperatures for the three and nine months ended September 30 were as follows (in millions):

| Electric Margins |  | Gas Margins
| Three Months |  | Nine Months |  | Three Months |  | Nine Months
| 2023 |  | 2022 |  | Change |  | 2023 |  | 2022 |  | Change |  | 2023 |  | 2022 |  | Change |  | 2023 |  | 2022 |  | Change
IPL | $7 |  | $4 |  | $3 |  | $3 |  | $15 |  | ($12) |  | ($1) |  | $— |  | ($1) |  | ($4) |  | $4 |  | ($8)
WPL | 3 |  | — |  | 3 |  | (2) |  | 10 |  | (12) |  | — |  | — |  | — |  | (4) |  | 2 |  | (6)
Total Alliant Energy | $10 |  | $4 |  | $6 |  | $1 |  | $25 |  | ($24) |  | ($1) |  | $— |  | ($1) |  | ($8) |  | $6 |  | ($14)

Electric Sales for Resale - Electric sales for resale volume changes were largely 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 sales for resale revenues were largely offset by changes in fuel-related costs, and therefore, did not have a significant impact on electric margins.
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. Changes in these transportation/other revenues did not have a significant impact on gas margins.
Utility Electric Margin Variances - The following items contributed to increased (decreased) utility electric margins for the three and nine months ended September 30, 2023 compared to the same periods in 2022 as follows (in millions):

| Three Months |  | Nine Months
| Alliant Energy |  | IPL |  | WPL |  | Alliant Energy |  | IPL |  | WPL
Lower (higher) WPL electric fuel-related costs, net of recoveries | ($1) |  | $— |  | ($1) |  | $12 |  | $— |  | $12
Higher (lower) revenues at IPL due to changes in the renewable energy rider (mostly offset by changes in income taxes) | (3) |  | (3) |  | — |  | 9 |  | 9 |  | —
Estimated changes in sales volumes caused by temperatures | 6 |  | 3 |  | 3 |  | (24) |  | (12) |  | (12)
Other | — |  | (4) |  | 4 |  | 11 |  | (1) |  | 11
| $2 |  | ($4) |  | $6 |  | $8 |  | ($4) |  | $11

Utility Gas Margin Variances - The following items contributed to increased (decreased) utility gas margins for the three and nine months ended September 30, 2023 compared to the same periods in 2022 as follows (in millions):

| Three Months |  | Nine Months
| Alliant Energy |  | IPL |  | WPL |  | Alliant Energy |  | IPL |  | WPL
Estimated changes in sales volumes caused by temperatures | ($1) |  | ($1) |  | $— |  | ($14) |  | ($8) |  | ($6)
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) | — |  | — |  | — |  | 7 |  | 7 |  | —
Higher revenue requirements at WPL (a) | 1 |  | — |  | 1 |  | 6 |  | — |  | 6
Other | (1) |  | 1 |  | (1) |  | (1) |  | — |  | —
| ($1) |  | $— |  | $— |  | ($2) |  | ($1) |  | $—

(a)In December 2022, the PSCW issued an order authorizing an annual base rate increase of $9 million for WPL’s retail gas customers, covering the 2023 forward-looking Test Period, which reflects changes in weighted average cost of capital, updated depreciation rates and modifications to certain regulatory asset and regulatory liability amortizations. These retail gas rate changes were effective on January 1, 2023 and extend through the end of 2023.

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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, 2023 compared to the same periods in 2022 as follows (in millions):

| Three Months |  | Nine Months
| Alliant Energy |  | IPL |  | WPL |  | Alliant Energy |  | IPL |  | WPL
Higher energy efficiency expense at IPL (mostly offset by higher revenues) | ($1) |  | ($1) |  | $— |  | ($10) |  | ($10) |  | $—
Lower (higher) generation and energy delivery expenses | 3 |  | 1 |  | 2 |  | (8) |  | — |  | (8)
Other | 10 |  | 6 |  | 4 |  | 11 |  | 6 |  | 4
| $12 |  | $6 |  | $6 |  | ($7) |  | ($4) |  | ($4)

Other Income and Deductions Variances - The following items contributed to (increased) decreased other income and deductions for the three and nine months ended September 30, 2023 compared to the same periods in 2022 as follows (in millions):

| Three Months |  | Nine Months
| Alliant Energy |  | IPL |  | WPL |  | Alliant Energy |  | IPL |  | WPL
Higher interest expense primarily due to financings completed in 2023 and 2022, and higher interest rates | ($16) |  | ($1) |  | ($7) |  | ($54) |  | ($2) |  | ($24)
Higher AFUDC primarily due to changes in construction work in progress balances related to WPL’s solar generation | 18 |  | 3 |  | 15 |  | 37 |  | 5 |  | 32
Other | 8 |  | (3) |  | 2 |  | 6 |  | (5) |  | 3
| $10 |  | ($1) |  | $10 |  | ($11) |  | ($2) |  | $11

Income Taxes - Refer to Note 9 for details of effective income tax rates.
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 $225 million of common stock in 2024 through one or more offerings and its Shareowner Direct Plan. The amount of common stock issued in 2024 will largely be used to fund capital contributions from Alliant Energy to WPL, which is dependent on the PSCW's decision on WPL's common equity component of its capital structure for the 2024/2025 forward-looking Test Period. IPL and AEF currently expect to issue up to $700 million and $1.0 billion of long-term debt, respectively, by the end of 2024. IPL and AEF have $500 million and $400 million of long-term debt, respectively, and AEF has $50 million of short-term borrowings, maturing in 2024.
• Common Stock Dividends - Alliant Energy announced a 6% increase in its expected targeted 2024 annual common stock dividend to $1.92 per share, which is equivalent to a quarterly rate of $0.48 per share, beginning with the February 2024 dividend payment. The timing and amount of future dividends is subject to approved 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 pursuant to the Inflation Reduction Act of 2022.
• Higher Earnings on Increasing Rate Base - Alliant Energy, IPL and WPL currently expect an increase in earnings in 2024 compared to 2023 due to impacts from increasing revenue requirements related to investments in the utility business.
• Depreciation and Amortization Expense - Alliant Energy, IPL and WPL currently expect an increase in depreciation and amortization expense in 2024 compared to 2023 due to capital projects placed in service in 2023 and 2024 and lower amortization of WPL’s West Riverside liquidated damages. Refer to Note 2 for discussion of WPL’s West Riverside liquidated damages.
• Interest Expense - Alliant Energy, IPL and WPL currently expect an increase in interest expense in 2024 compared to 2023 due to financings completed in 2023 and planned by the end of 2024 as discussed above, as well as expected higher interest rates.
• AFUDC - Alliant Energy and WPL currently expect a decrease and IPL currently expects an increase in AFUDC in 2024 compared to 2023 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 2022 Form 10-K has not changed materially, except as described below.

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Liquidity Position - At September 30, 2023, Alliant Energy had $206 million of cash and cash equivalents, $549 million ($119 million at the parent company, $250 million at IPL and $180 million at WPL) of available capacity under the single revolving credit facility and $109 million of available capacity at IPL under its sales of accounts receivable program.
Capital Structure - Capital structures at September 30, 2023 were as follows (Long-term Debt (including current maturities) (LD); Short-term Debt (SD); Common Equity (CE)):
Cash Flows - Selected information from the cash flows statements was as follows (in millions):

| Alliant Energy |  | IPL |  | WPL
| 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022
Cash, cash equivalents and restricted cash, January 1 | $24 |  | $40 |  | $15 |  | $34 |  | $5 |  | $2
Cash flows from (used for): |  |  |  |  |  |  |  |  |  |  |
Operating activities | 622 |  | 485 |  | 191 |  | 166 |  | 437 |  | 279
Investing activities | (952) |  | (599) |  | (177) |  | 84 |  | (680) |  | (612)
Financing activities | 515 |  | 421 |  | 159 |  | (239) |  | 254 |  | 630
Net increase | 185 |  | 307 |  | 173 |  | 11 |  | 11 |  | 297
Cash, cash equivalents and restricted cash, September 30 | $209 |  | $347 |  | $188 |  | $45 |  | $16 |  | $299

Operating Activities - The following items contributed to increased (decreased) operating activity cash flows for the nine months ended September 30, 2023 compared to the same period in 2022 (in millions):

| Alliant Energy |  | IPL |  | WPL
Timing of WPL’s fuel-related cost recoveries from retail electric customers | $137 |  | $— |  | $137
Changes in levels of gas stored underground and prepaid gas costs | 97 |  | 46 |  | 51
Changes in the sales of accounts receivable at IPL | 36 |  | 36 |  | —
Changes in interest payments | (60) |  | 4 |  | (28)
Decreased collections from IPL’s and WPL’s retail customers caused by temperature impacts on electric and gas sales | (38) |  | (20) |  | (18)
Other (primarily due to other changes in working capital) | (35) |  | (41) |  | 16
| $137 |  | $25 |  | $158

Investing Activities - The following items contributed to increased (decreased) investing activity cash flows for the nine months ended September 30, 2023 compared to the same period in 2022 (in millions):

| Alliant Energy |  | IPL |  | WPL
Higher utility construction and acquisition expenditures (a) | ($328) |  | ($158) |  | ($170)
Changes in the amount of cash receipts on sold receivables | (52) |  | (52) |  | —
Higher non-utility construction and acquisition expenditures | (23) |  | — |  | —
Proceeds from sales of partial ownership interest in West Riverside in 2023 | 120 |  | — |  | 120
Other | (70) |  | (51) |  | (18)
| ($353) |  | ($261) |  | ($68)

(a)Largely due to higher expenditures for IPL and WPL’s solar generation.

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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 regulatory requirements, changing legislation, not obtaining favorable and acceptable regulatory approval on certain projects, improvements in technology, and improvements to ensure resiliency and reliability of the electric and gas distribution systems. Construction and acquisition expenditures for 2023 through 2027 are currently anticipated as follows (in millions), which are focused on the transition to cleaner energy and strengthening the resiliency and reliability of IPL’s and WPL’s electric grid, and include renewables and battery storage projects, dispatchable gas generation projects and wind repowering projects. Cost estimates represent Alliant Energy’s, IPL’s and WPL’s portion of construction expenditures and exclude AFUDC and capitalized interest, if applicable.

| Alliant Energy |  | IPL |  | WPL
| 2023 | 2024 | 2025 | 2026 | 2027 |  | 2023 | 2024 | 2025 | 2026 | 2027 |  | 2023 | 2024 | 2025 | 2026 | 2027
Generation: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Renewables and battery storage projects | $790 |  | $1,140 |  | $665 |  | $780 |  | $775 |  |  | $350 |  | $575 |  | $275 |  | $445 |  | $205 |  |  | $440 |  | $565 |  | $390 |  | $335 |  | $570 |
Gas projects | 40 |  | 120 |  | 325 |  | 610 |  | 500 |  |  | 10 |  | 55 |  | 135 |  | 310 |  | 125 |  |  | 30 |  | 15 |  | 125 |  | 295 |  | 375 |
Other | 95 |  | 100 |  | 80 |  | 50 |  | 40 |  |  | 55 |  | 55 |  | 40 |  | 20 |  | 15 |  |  | 40 |  | 45 |  | 40 |  | 30 |  | 25 |
Distribution: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Electric systems | 565 |  | 610 |  | 620 |  | 670 |  | 685 |  |  | 305 |  | 355 |  | 365 |  | 380 |  | 395 |  |  | 260 |  | 255 |  | 255 |  | 290 |  | 290 |
Gas systems | 80 |  | 85 |  | 85 |  | 85 |  | 85 |  |  | 35 |  | 40 |  | 40 |  | 40 |  | 40 |  |  | 45 |  | 45 |  | 45 |  | 45 |  | 45 |
Other | 220 |  | 220 |  | 205 |  | 240 |  | 280 |  |  | 50 |  | 45 |  | 50 |  | 50 |  | 45 |  |  | 35 |  | 40 |  | 30 |  | 25 |  | 30 |
| $1,790 |  | $2,275 |  | $1,980 |  | $2,435 |  | $2,365 |  |  | $805 |  | $1,125 |  | $905 |  | $1,245 |  | $825 |  |  | $850 |  | $965 |  | $885 |  | $1,020 |  | $1,335 |

Financing Activities - The following items contributed to increased (decreased) financing activity cash flows for the nine months ended September 30, 2023 compared to the same period in 2022 (in millions):

| Alliant Energy |  | IPL |  | WPL
Higher net proceeds from common stock issuances | $182 |  | $— |  | $—
Distributions to noncontrolling interest in 2022 | 29 |  | — |  | 29
Higher (lower) capital contributions from IPL’s and WPL’s parent company, Alliant Energy | — |  | 60 |  | (175)
Higher (lower) net proceeds from issuance of long-term debt | (80) |  | 296 |  | (291)
Capital contributions from noncontrolling interest in 2022 | (29) |  | — |  | (29)
Higher payments to retire long-term debt | (25) |  | — |  | —
(Higher) lower common stock dividends | (19) |  | 30 |  | (5)
Net changes in the amount of commercial paper and other short-term borrowings outstanding | (9) |  | — |  | 66
Other | 45 |  | 12 |  | 29
| $94 |  | $398 |  | ($376)

State Regulatory Financing Authorization - In March 2023, WPL received authorization from the PSCW to have up to $500 million of short-term borrowings and/or letters of credit outstanding at any time through the expiration date of WPL’s credit facility agreement.
Common Stock Issuances and Common Stock Dividends - Refer to Note 6 for discussion of common stock issuances by Alliant Energy in 2023. Refer to “Results of Operations” for discussion of expected issuances of common stock and common stock dividends in 2024.
Short-term Debt - Refer to N ote 7(a) for discussion of Alliant Energy’s, IPL’s and WPL’s single credit facility agreement that was amended and extended in March 2023, which includes a revised cross-default provision related to prepayment of material debt prior to the stated maturity and certain other confirming changes, as well as details for proceeds from AEF’s December 2022 term loan credit agreement.
Long-term Debt - Refer to Note 7(b) for discussion of various issuances and retirements of long-term debt by Alliant Energy, AEF, IPL and WPL in 2023. Refer to “Results of Operations” for discussion of expected future issuances and retirements of long-term debt by the end of 2024.
Interest Rate Risk - As of September 30, 2023, Alliant Energy’s exposure to risk resulting from changes in interest rates associated with variable-rate borrowings was mitigated primarily due to its issuance of convertible senior notes and an interest rate swap on a portion of its variable-rate term loan borrowings, as well as WPL’s issuance of green bonds and IPL’s issuance of senior debentures, all of which were executed in 2023. Assuming the impact of a hypothetical 100 basis point increase in interest rates on variable-rate borrowings and cash amounts outstanding under IPL’s sales of accounts receivable program at September 30, 2023, Alliant Energy’s annual pre-tax expense would increase by approximately $6 million.

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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 2022 Form 10-K and has not changed materially from the items reported in the 2022 Form 10-K, except for the items described in Notes 4, 7 and 1 3.
OTHER MATTERS
Critical Accounting Policies and Estimates - The summary of critical accounting policies and estimates included in the 2022 Form 10-K has not changed materially, except as described below.
Long-Lived Assets -
Regulated Operations -
Generating Units Subject to Early Retirement - In May 2023, IPL retired the Lansing Generating Station. IPL is currently allowed a full recovery of and a full return on this EGU from both its retail and wholesale customers, and as a result, Alliant Energy and IPL concluded that no impairment was required as of September 30, 2023. Refer to Note 2 for further discussion of the Lansing retirement.
IPL’s Solar Generation Projects Under Construction - As discussed in “2023 Highlights,” IPL accepted the IUB’s advance rate-making principles approved in October 2023 for 400 MW of solar generation. Alliant Energy and IPL review property, plant and equipment for possible impairment whenever events or changes in circumstances indicate all or a portion of the carrying value of the assets may be disallowed for rate-making purposes. If IPL is disallowed recovery of any portion of, or is only allowed a partial return on, the carrying value of the solar generation projects under construction, then an impairment charge is recognized. IPL currently expects estimated construction costs associated with the 400 MW of new solar generation will exceed the cost target approved by the IUB by approximately 10%. Alliant Energy and IPL concluded that there was not a probable disallowance of anticipated higher rate base amounts as of September 30, 2023 given construction costs were reasonably and prudently incurred.
Environmental Matters - The summary of environmental matters included in the 2022 Form 10-K has not changed materially, except as described below.
Environmental Regulation -
Clean Air Act (CAA) Section 111(d) - In May 2023, the EPA published proposed standards under Section 111(d) of the CAA, which establish emission guidelines for states to implement Best System of Emission Reduction standards for greenhouse gases emissions from existing fossil-fueled EGUs and certain combustion turbines, and would be phased in beginning in 2030. The EPA also proposed to repeal the Affordable Clean Energy rule. The EPA’s proposed standards would require states to implement plans to reduce carbon dioxide emissions from existing fossil-fueled EGUs and certain combustion turbines through various measures, including retirement, enforceable limits on operational capacity, co-firing with low-greenhouse gases fuels, or other technological controls. State plans must be submitted within 24 months of the final rule’s effective date and are subject to EPA approval. The proposed standards could impact IPL’s coal-fired Ottumwa Generating Station, George Neal Generating Station, Prairie Creek Generating Station Unit 3 and Louisa Generating Station, and IPL’s natural gas-fired Burlington Generating Station and Prairie Creek Generating Station Unit 4. In addition, the proposed standards could impact natural gas-fired combustion turbines with a capacity of 300 MW or more, including IPL’s Marshalltown Generating Station and Emery Generating Station, and WPL’s Riverside Energy Center and West Riverside Energy Center. The proposed standards are currently not expected to impact WPL’s coal-fired Columbia Energy Center or Edgewater Generating Station given current plans to retire these EGUs prior to the proposed 2030 implementation deadline. The timeline for expected issuance of the EPA’s final reconsidered 111(d) rule cannot be predicted with certainty, but is expected to be issued in 2024. Alliant Energy, IPL and WPL are currently unable to predict with certainty the future outcome or impact of these matters.
Clean Air Act Section 111(b) - In May 2023, the EPA published proposed standards under Section 111(b) of the CAA, which establish carbon dioxide emissions limits from certain new and reconstructed fossil-fueled EGUs and would apply prospectively. The timeline for expected issuance of the EPA’s final reconsidered 111(b) rule cannot be predicted with certainty, but is expected to be issued in 2024. Marshalltown and West Riverside are currently subject to the EPA’s Section 111(b) regulation. Alliant Energy, IPL and WPL are currently unable to predict with certainty the future outcome or impact of these standards.
Coal Combustion Residuals (CCR) Rule - In May 2023, the EPA published proposed amendments to the CCR Rule, which regulates CCR as a non-hazardous waste. These proposed amendments would expand the scope of regulation to include coal ash ponds at sites that no longer produce electricity and inactive landfills, including some IPL and WPL facilities. Alliant Energy, IPL and WPL are currently unable to predict with certainty the future outcome or impact of these updates.
Environmental Stewardship - Alliant Energy’s current voluntary environmental-related goals include the following:
•By 2030, reduce greenhouse gases 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 and reduce greenhouse gases emissions from its utility operations by 80% from 2005 levels.

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•By 2050, aspire to achieve net-zero greenhouse gases emissions from its utility operations.
Alliant Energy’s aspirational greenhouse gases 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. In addition, Alliant Energy’s environmental stewardship efforts include a goal to partner to plant more than 1 million trees by the end of 2030. Future updates to sustainable energy plans and attaining these goals will depend on future economic developments, evolving energy technologies and emerging trends in Alliant Energy’s service territories.
ITEM 3. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK
Quantitative and Qualitative Disclosures About Market Risk are reported in the 2022 Form 10-K and have not changed materially.
ITEM 4. CONTROLS AND PROCEDURES
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, 2023 pursuant to the requirements of the Securities Exchange Act of 1934, as amended. Based on their evaluation, the Chief Executive Officers 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, 2023.
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, 2023 that has materially affected, or is reasonably likely to materially affect, Alliant Energy’s, IPL’s or WPL’s internal control over financial reporting.
PART II. OTHER INFORMATION
ITEM 1. LEGAL PROCEEDINGS
None. SEC regulations require Alliant Energy, IPL and WPL to disclose information about certain proceedings arising under federal, state or local environmental provisions when a governmental authority is a party to the proceedings and such proceedings involve potential monetary sanctions that Alliant Energy, IPL and WPL reasonably believe will exceed a specified threshold. Pursuant to the SEC regulations, Alliant Energy, IPL and WPL use a threshold of $1 million for purposes of determining whether disclosure of any such proceedings is required. Applying this threshold, there are no environmental matters to disclose for this period.
ITEM 1A. RISK FACTORS
The risk factors described in Item 1A in the 2022 Form 10-K have not changed materially.
ITEM 2. UNREGISTERED SALES OF EQUITY SECURITIES, USE OF PROCEEDS AND ISSUER PURCHASES OF EQUITY SECURITIES
A summary of Alliant Energy common stock repurchases for the quarter ended September 30, 2023 was as follows:

|  | Total Number |  | Average Price |  | Total Number of Shares |  | Maximum Number (or Approximate
|  | of Shares |  | Paid Per |  | Purchased as Part of |  | Dollar Value) of Shares That May
Period |  | Purchased (a) |  | Share |  | Publicly Announced Plan |  | Yet Be Purchased Under the Plan (a)
July 1 through July 31 |  | 6,298 |  | $52.95 |  | — |  | N/A
August 1 through August 31 |  | 3,724 |  | 50.31 |  | — |  | N/A
September 1 through September 30 |  | 38 |  | 49.97 |  | — |  | N/A
|  | 10,060 |  | 51.97 |  | — |  |

(a)All shares were purchased on the open market and held in a rabbi trust under the Alliant Energy Deferred Compensation Plan. There is no limit on the number of shares of Alliant Energy common stock that may be held under the Deferred Compensation Plan, which currently does not have an expiration date.
ITEM 5. OTHER INFORMATION
(c)During the quarter ended September 30, 2023, no director or officer of Alliant Energy, IPL or WPL adopted or terminated a Rule 10b5-1 trading arrangement or non-Rule 10b5-1 trading arrangement, as each term is defined in Item 408(a) of Regulation S-K.

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ITEM 6. EXHIBITS
The following Exhibits are filed herewith or incorporated herein by reference.

Exhibit Number | Description
4.1 | Officer’s Certificate, dated as of September 21, 2023, creating IPL’s 5.7 0% Senior Debentures due October 15, 20 33 (incorporated by reference to Exhibit 4.1 to IPL’s Form 8-K, filed September 21, 2023 (File No. 1-4117))
31.1 | Certification of the Chief Executive Officer for Alliant Energy
31.2 | Certification of the Chief Financial Officer for Alliant Energy
31.3 | Certification of the Chief Executive Officer for IPL
31.4 | Certification of the Chief Financial Officer for IPL
31.5 | Certification of the Chief Executive Officer for WPL
31.6 | Certification of the Chief Financial Officer for WPL
32.1 | Written Statement of the Chief Executive Officer and Chief Financial Officer Pursuant to 18 U.S.C.§1350 for Alliant Energy
32.2 | Written Statement of the Chief Executive Officer and Chief Financial Officer Pursuant to 18 U.S.C.§1350 for IPL
32.3 | Written Statement of the Chief Executive Officer and Chief Financial Officer Pursuant to 18 U.S.C.§1350 for WPL
101.INS | Inline XBRL Instance Document - the instance document does not appear in the Interactive Data File because its XBRL tags are embedded within the Inline XBRL document
101.SCH | Inline XBRL Taxonomy Extension Schema Document
101.CAL | Inline XBRL Taxonomy Extension Calculation Linkbase Document
101.LAB | Inline XBRL Taxonomy Extension Label Linkbase Document
101.PRE | Inline XBRL Taxonomy Extension Presentation Linkbase Document
101.DEF | Inline XBRL Taxonomy Extension Definition Linkbase Document
104 | Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934, Alliant Energy Corporation, Interstate Power and Light Company and Wisconsin Power and Light Company have each duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized on the 3rd day of November 2023.

ALLIANT ENERGY CORPORATION |
Registrant |
By: /s/ Benjamin M. Bilitz | Chief Accounting Officer and Controller
Benjamin M. Bilitz | (Principal Accounting Officer and Authorized Signatory)

INTERSTATE POWER AND LIGHT COMPANY |
Registrant |
By: /s/ Benjamin M. Bilitz | Chief Accounting Officer and Controller
Benjamin M. Bilitz | (Principal Accounting Officer and Authorized Signatory)

WISCONSIN POWER AND LIGHT COMPANY |
Registrant |
By: /s/ Benjamin M. Bilitz | Chief Accounting Officer and Controller
Benjamin M. Bilitz | (Principal Accounting Officer and Authorized Signatory)

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