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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, 2021
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
Interstate Power and Light Company, 5.100% Series D Cumulative Perpetual Preferred Stock, $0.01 Par Value, Trading Symbol IPLDP, 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, 2021:
Alliant Energy Corporation, Common Stock, $0.01 par value, 250,360,787 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. Receivables | 13
4. Investments | 13
5. Common Equity | 14
6. Preferred Stock | 16
7. Debt | 16
8. Revenues | 17
9. Income Taxes | 17
10. Benefit Plans | 18
11. Asset Retirement Obligations | 19
12. Derivative Instruments | 19
13. Fair Value Measurements | 20
14. Commitments and Contingencies | 22
15. Segments of Business | 23
16. Related Parties | 24
Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations | 25
Item 3. Quantitative and Qualitative Disclosures About Market Risk | 34
Item 4. Controls and Procedures | 34
Part II. Other Information | 34
Item 1. Legal Proceedings | 34
Item 1A. Risk Factors | 34
Item 2. Unregistered Sales of Equity Securities and Use of Proceeds | 34
Item 6. Exhibits | 35
Signatures | 35

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

Abbreviation or Acronym | Definition | Abbreviation or Acronym | Definition
2020 Form 10-K | Combined Annual Report on Form 10-K filed by Alliant Energy, IPL and WPL for the year ended Dec. 31, 2020 | GAAP | U.S. generally accepted accounting principles
AEF | Alliant Energy Finance, LLC | IPL | Interstate Power and Light Company
AFUDC | Allowance for funds used during construction | IUB | Iowa Utilities Board
Alliant Energy | Alliant Energy Corporation | MDA | Management’s Discussion and Analysis of Financial Condition and Results of Operations
ATC | American Transmission Company LLC | MISO | Midcontinent Independent System Operator, Inc.
ATC Holdings | Interest in American Transmission Company LLC and ATC Holdco LLC | MW | Megawatt
Corporate Services | Alliant Energy Corporate Services, Inc. | MWh | Megawatt-hour
COVID-19 | Novel coronavirus | N/A | Not applicable
DAEC | Duane Arnold Energy Center | 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
Federal Tax Reform | Tax Cuts and Jobs Act | U.S. | United States of America
FERC | Federal Energy Regulatory Commission | West Riverside | West Riverside Energy Center
Financial Statements | Condensed Consolidated Financial Statements | Whiting Petroleum | Whiting Petroleum Corporation
FTR | Financial transmission right | 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 the COVID-19 pandemic, including vaccine mandates and testing requirements, on sales volumes, margins, operations, employees, contractors, vendors, the ability to complete construction projects, supply chains, customers’ inability to pay bills, suspension of disconnects, the market value of the assets that fund pension plans and the potential for additional funding requirements, the ability of counterparties to meet their obligations, compliance with regulatory requirements, the ability to implement regulatory plans, economic conditions and access to capital markets;
•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;
•the direct or indirect effects resulting from terrorist incidents, including physical attacks and cyber attacks, 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;
•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, deferred expenditures, deferred tax assets, tax 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;
•federal and state regulatory or governmental actions, including the impact of legislation, and regulatory agency orders;
•the ability to utilize tax credits and net operating losses generated to date, and those that may be generated in the future, before they expire;

| 1 |

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•the impacts of changes in the tax code, including tax rates, minimum tax rates, and adjustments made to deferred tax assets and liabilities;
•employee workforce factors, including changes in key executives, ability to hire and retain employees with specialized skills, ability to create desired corporate culture, collective bargaining agreements and negotiations, work stoppages or restructurings;
•any material post-closing payments 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;
•issues associated with environmental remediation and environmental compliance, including compliance with all environmental and emissions permits, the Coal Combustion Residuals Rule, future changes in environmental laws and regulations, including federal, state or local regulations for carbon dioxide emissions reductions from new and existing fossil-fueled EGUs, and litigation associated with environmental requirements;
•increased pressure from customers, investors and other stakeholders to more rapidly reduce carbon dioxide emissions;
•the ability to defend against environmental claims brought by state and federal agencies, such as the EPA, state natural resources agencies or third parties, such as the Sierra Club, and the impact on operating expenses of defending and resolving such claims;
•continued access to the capital markets on competitive terms and rates, and the actions of credit rating agencies;
•inflation and interest rates;
•the ability to complete construction of solar generation projects within the cost targets set by regulators due to cost increases of materials, equipment and commodities including due to tariffs, labor issues or supply shortages, the ability to achieve the expected level of tax benefits based on tax guidelines and project costs, and the ability to efficiently utilize the solar generation project tax benefits for the benefit of customers;
•disruptions to the supply of materials, equipment and commodities needed to construct solar generation projects, including due to shortages, labor issues or transportation issues, which may impact the ability to meet capacity requirements and result in increased capacity expense;
•changes in the price of delivered natural gas, transmission, purchased electricity and coal due to shifts in supply and demand caused by market conditions and regulations;
•disruptions in the supply and delivery of natural gas, purchased electricity and coal;
•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, 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 costs through rates;
•impacts that excessive heat, excessive cold, storms or natural disasters 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;
•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;
•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 valuations and 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;
•changes to the creditworthiness of counterparties with which Alliant Energy, IPL and WPL have contractual arrangements, including participants in the energy markets and fuel suppliers and transporters;
•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 2020 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.

| 2 |

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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,
| 2021 |  | 2020 |  | 2021 |  | 2020
| (in millions, except per share amounts)
Revenues: |  |  |  |  |  |  |
Electric utility | $939 |  | $852 |  | $2,357 |  | $2,257
Gas utility | 50 |  | 42 |  | 289 |  | 253
Other utility | 13 |  | 10 |  | 36 |  | 32
Non-utility | 22 |  | 16 |  | 60 |  | 57
Total revenues | 1,024 |  | 920 |  | 2,742 |  | 2,599
Operating expenses: |  |  |  |  |  |  |
Electric production fuel and purchased power | 207 |  | 179 |  | 478 |  | 527
Electric transmission service | 148 |  | 132 |  | 403 |  | 326
Cost of gas sold | 18 |  | 11 |  | 149 |  | 117
Other operation and maintenance | 171 |  | 143 |  | 477 |  | 465
Depreciation and amortization | 165 |  | 156 |  | 494 |  | 454
Taxes other than income taxes | 26 |  | 27 |  | 78 |  | 82
Total operating expenses | 735 |  | 648 |  | 2,079 |  | 1,971
Operating income | 289 |  | 272 |  | 663 |  | 628
Other (income) and deductions: |  |  |  |  |  |  |
Interest expense | 68 |  | 68 |  | 206 |  | 207
Equity income from unconsolidated investments, net | (13) |  | (15) |  | (47) |  | (46)
Allowance for funds used during construction | (7) |  | (13) |  | (16) |  | (51)
Other | 3 |  | 3 |  | 7 |  | 7
Total other (income) and deductions | 51 |  | 43 |  | 150 |  | 117
Income before income taxes | 238 |  | 229 |  | 513 |  | 511
Income tax benefit | (21) |  | (20) |  | (66) |  | (47)
Net income | 259 |  | 249 |  | 579 |  | 558
Preferred dividend requirements of Interstate Power and Light Company | 3 |  | 3 |  | 8 |  | 8
Net income attributable to Alliant Energy common shareowners | $256 |  | $246 |  | $571 |  | $550
Weighted average number of common shares outstanding: |  |  |  |  |  |  |
Basic | 250.3 |  | 249.7 |  | 250.2 |  | 247.9
Diluted | 250.8 |  | 250.0 |  | 250.6 |  | 248.1
Earnings per weighted average common share attributable to Alliant Energy common shareowners: |  |  |  |  |  |  |
Basic | $1.02 |  | $0.99 |  | $2.28 |  | $2.22
Diluted | $1.02 |  | $0.98 |  | $2.28 |  | $2.22

Refer to accompanying Combined Notes to Condensed Consolidated Financial Statements.

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ALLIANT ENERGY CORPORATION
CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED)

| September 30, 2021 |  | December 31, 2020
| (in millions, except per share and share amounts)
ASSETS |  |  |
Current assets: |  |  |
Cash and cash equivalents | $20 |  | $54
Accounts receivable, less allowance for expected credit losses | 392 |  | 412
Production fuel, at weighted average cost | 42 |  | 66
Gas stored underground, at weighted average cost | 58 |  | 46
Materials and supplies, at weighted average cost | 118 |  | 105
Regulatory assets | 111 |  | 81
Other | 274 |  | 123
Total current assets | 1,015 |  | 887
Property, plant and equipment, net | 14,738 |  | 14,336
Investments: |  |  |
ATC Holdings | 338 |  | 331
Other | 176 |  | 154
Total investments | 514 |  | 485
Other assets: |  |  |
Regulatory assets | 1,907 |  | 1,929
Deferred charges and other | 155 |  | 73
Total other assets | 2,062 |  | 2,002
Total assets | $18,329 |  | $17,710

LIABILITIES AND EQUITY |  |  |
Current liabilities: |  |  |
Current maturities of long-term debt | $383 |  | $8
Commercial paper | 316 |  | 389
Accounts payable | 361 |  | 377
Regulatory liabilities | 231 |  | 249
Other | 266 |  | 274
Total current liabilities | 1,557 |  | 1,297
Long-term debt, net (excluding current portion) | 6,692 |  | 6,769
Other liabilities: |  |  |
Deferred tax liabilities | 1,906 |  | 1,814
Regulatory liabilities | 1,130 |  | 1,057
Pension and other benefit obligations | 452 |  | 511
Other | 407 |  | 374
Total other liabilities | 3,895 |  | 3,756
Commitments and contingencies (N ot e 14) |  |  |
Equity: |  |  |
Alliant Energy Corporation common equity: |  |  |
Common stock - $0.01 par value - 480,000,000 shares authorized; 250,360,787 and 249,868,415 shares | 3 |  | 2
Additional paid-in capital | 2,733 |  | 2,704
Retained earnings | 3,261 |  | 2,994
Accumulated other comprehensive loss | (1) |  | (1)
Shares in deferred compensation trust - 377,875 and 380,542 shares at a weighted average cost of $30.14 and $28.73 per share | (11) |  | (11)
Total Alliant Energy Corporation common equity | 5,985 |  | 5,688
Cumulative preferred stock of Interstate Power and Light Company | 200 |  | 200
Total equity | 6,185 |  | 5,888
Total liabilities and equity | $18,329 |  | $17,710

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,
| 2021 |  | 2020
| (in millions)
Cash flows from operating activities: |  |  |
Net income | $579 |  | $558
Adjustments to reconcile net income to net cash flows from operating activities: |  |  |
Depreciation and amortization | 494 |  | 454
Deferred tax benefit and tax credits | (69) |  | (48)
Other | 7 |  | (17)
Other changes in assets and liabilities: |  |  |
Accounts receivable | (397) |  | (316)
Derivative assets | (202) |  | (22)
Regulatory liabilities | 25 |  | (72)
Deferred income taxes | 160 |  | 143
Pension and other benefit obligations | (59) |  | (61)
DAEC PPA amendment buyout payment | — |  | (110)
Other | (61) |  | (73)
Net cash flows from operating activities | 477 |  | 436
Cash flows used for investing activities: |  |  |
Construction and acquisition expenditures: |  |  |
Utility business | (772) |  | (935)
Other | (60) |  | (39)
Cash receipts on sold receivables | 423 |  | 318
Other | (43) |  | (23)
Net cash flows used for investing activities | (452) |  | (679)
Cash flows from (used for) financing activities: |  |  |
Common stock dividends | (304) |  | (281)
Proceeds from issuance of common stock, net | 22 |  | 241
Proceeds from issuance of long-term debt | 300 |  | 1,050
Payments to retire long-term debt | (4) |  | (654)
Net change in commercial paper | (73) |  | 85
Other | 2 |  | (22)
Net cash flows from (used for) financing activities | (57) |  | 419
Net increase (decrease) in cash, cash equivalents and restricted cash | (32) |  | 176
Cash, cash equivalents and restricted cash at beginning of period | 56 |  | 18
Cash, cash equivalents and restricted cash at end of period | $24 |  | $194
Supplemental cash flows information: |  |  |
Cash (paid) refunded during the period for: |  |  |
Interest | ($197) |  | ($197)
Income taxes, net | ($1) |  | $6
Significant non-cash investing and financing activities: |  |  |
Accrued capital expenditures | $91 |  | $202
Beneficial interest obtained in exchange for securitized accounts receivable | $164 |  | $201

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,
| 2021 |  | 2020 |  | 2021 |  | 2020
| (in millions)
Revenues: |  |  |  |  |  |  |
Electric utility | $555 |  | $519 |  | $1,343 |  | $1,332
Gas utility | 31 |  | 24 |  | 165 |  | 141
Steam and other | 13 |  | 10 |  | 35 |  | 31
Total revenues | 599 |  | 553 |  | 1,543 |  | 1,504
Operating expenses: |  |  |  |  |  |  |
Electric production fuel and purchased power | 101 |  | 102 |  | 215 |  | 304
Electric transmission service | 103 |  | 93 |  | 274 |  | 212
Cost of gas sold | 12 |  | 6 |  | 84 |  | 63
Other operation and maintenance | 95 |  | 85 |  | 253 |  | 269
Depreciation and amortization | 94 |  | 89 |  | 281 |  | 264
Taxes other than income taxes | 14 |  | 16 |  | 42 |  | 45
Total operating expenses | 419 |  | 391 |  | 1,149 |  | 1,157
Operating income | 180 |  | 162 |  | 394 |  | 347
Other (income) and deductions: |  |  |  |  |  |  |
Interest expense | 34 |  | 35 |  | 103 |  | 104
Allowance for funds used during construction | (2) |  | (6) |  | (7) |  | (21)
Other | — |  | 1 |  | 2 |  | 3
Total other (income) and deductions | 32 |  | 30 |  | 98 |  | 86
Income before income taxes | 148 |  | 132 |  | 296 |  | 261
Income tax benefit | (12) |  | (19) |  | (34) |  | (37)
Net income | 160 |  | 151 |  | 330 |  | 298
Preferred dividend requirements | 3 |  | 3 |  | 8 |  | 8
Net income available for common stock | $157 |  | $148 |  | $322 |  | $290

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, 2021 |  | December 31, 2020
| (in millions, except per share and share amounts)
ASSETS |
Current assets: |  |  |
Cash and cash equivalents | $13 |  | $50
Accounts receivable, less allowance for expected credit losses | 205 |  | 210
Production fuel, at weighted average cost | 32 |  | 48
Gas stored underground, at weighted average cost | 33 |  | 20
Materials and supplies, at weighted average cost | 71 |  | 63
Regulatory assets | 86 |  | 52
Other | 108 |  | 53
Total current assets | 548 |  | 496
Property, plant and equipment, net | 7,931 |  | 7,889
Other assets: |  |  |
Regulatory assets | 1,421 |  | 1,431
Deferred charges and other | 78 |  | 33
Total other assets | 1,499 |  | 1,464
Total assets | $9,978 |  | $9,849

LIABILITIES AND EQUITY |
Current liabilities: |  |  |
Accounts payable | $140 |  | $162
Regulatory liabilities | 104 |  | 103
Other | 171 |  | 182
Total current liabilities | 415 |  | 447
Long-term debt, net | 3,347 |  | 3,345
Other liabilities: |  |  |
Deferred tax liabilities | 1,079 |  | 1,035
Regulatory liabilities | 616 |  | 573
Pension and other benefit obligations | 161 |  | 186
Other | 325 |  | 299
Total other liabilities | 2,181 |  | 2,093
Commitments and contingencies (Note 14) |  |  |
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 | 2,802 |  | 2,752
Retained earnings | 1,000 |  | 979
Total Interstate Power and Light Company common equity | 3,835 |  | 3,764
Cumulative preferred stock | 200 |  | 200
Total equity | 4,035 |  | 3,964
Total liabilities and equity | $9,978 |  | $9,849

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,
| 2021 |  | 2020
| (in millions)
Cash flows from operating activities: |  |  |
Net income | $330 |  | $298
Adjustments to reconcile net income to net cash flows from operating activities: |  |  |
Depreciation and amortization | 281 |  | 264
Deferred tax benefit and tax credits | (13) |  | (42)
Other | (1) |  | (9)
Other changes in assets and liabilities: |  |  |
Accounts receivable | (412) |  | (337)
Derivative assets | (86) |  | (12)
Regulatory assets | (33) |  | (32)
Regulatory liabilities | 30 |  | (11)
Deferred income taxes | 56 |  | 62
Pension and other benefit obligations | (25) |  | (19)
DAEC PPA amendment buyout payment | — |  | (110)
Other | (32) |  | (33)
Net cash flows from operating activities | 95 |  | 19
Cash flows from (used for) investing activities: |  |  |
Construction and acquisition expenditures | (285) |  | (465)
Cash receipts on sold receivables | 423 |  | 318
Other | (16) |  | (55)
Net cash flows from (used for) investing activities | 122 |  | (202)
Cash flows from (used for) financing activities: |  |  |
Common stock dividends | (301) |  | (177)
Capital contributions from parent | 50 |  | 345
Proceeds from issuance of long-term debt | — |  | 400
Payments to retire long-term debt | — |  | (200)
Other | (3) |  | (9)
Net cash flows from (used for) financing activities | (254) |  | 359
Net increase (decrease) in cash, cash equivalents and restricted cash | (37) |  | 176
Cash, cash equivalents and restricted cash at beginning of period | 50 |  | 9
Cash, cash equivalents and restricted cash at end of period | $13 |  | $185
Supplemental cash flows information: |  |  |
Cash (paid) refunded during the period for: |  |  |
Interest | ($106) |  | ($109)
Income taxes, net | $28 |  | ($12)
Significant non-cash investing and financing activities: |  |  |
Accrued capital expenditures | $30 |  | $150
Beneficial interest obtained in exchange for securitized accounts receivable | $164 |  | $201

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,
| 2021 |  | 2020 |  | 2021 |  | 2020
| (in millions)
Revenues: |  |  |  |  |  |  |
Electric utility | $384 |  | $333 |  | $1,014 |  | $925
Gas utility | 19 |  | 18 |  | 124 |  | 112
Other | — |  | — |  | 1 |  | 1
Total revenues | 403 |  | 351 |  | 1,139 |  | 1,038
Operating expenses: |  |  |  |  |  |  |
Electric production fuel and purchased power | 105 |  | 78 |  | 263 |  | 223
Electric transmission service | 44 |  | 39 |  | 128 |  | 114
Cost of gas sold | 6 |  | 4 |  | 65 |  | 53
Other operation and maintenance | 66 |  | 65 |  | 194 |  | 172
Depreciation and amortization | 70 |  | 65 |  | 209 |  | 186
Taxes other than income taxes | 12 |  | 11 |  | 35 |  | 35
Total operating expenses | 303 |  | 262 |  | 894 |  | 783
Operating income | 100 |  | 89 |  | 245 |  | 255
Other (income) and deductions: |  |  |  |  |  |  |
Interest expense | 25 |  | 26 |  | 77 |  | 78
Allowance for funds used during construction | (5) |  | (6) |  | (9) |  | (29)
Other | 2 |  | 1 |  | 3 |  | 3
Total other (income) and deductions | 22 |  | 21 |  | 71 |  | 52
Income before income taxes | 78 |  | 68 |  | 174 |  | 203
Income tax benefit | (15) |  | (5) |  | (41) |  | (17)
Net income | $93 |  | $73 |  | $215 |  | $220

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, 2021 |  | December 31, 2020
| (in millions, except per share and share amounts)
ASSETS |  |  |
Current assets: |  |  |
Cash and cash equivalents | $4 |  | $3
Accounts receivable, less allowance for expected credit losses | 175 |  | 192
Production fuel, at weighted average cost | 10 |  | 18
Gas stored underground, at weighted average cost | 25 |  | 26
Materials and supplies, at weighted average cost | 45 |  | 40
Regulatory assets | 25 |  | 29
Prepaid gross receipts tax | 29 |  | 42
Other | 99 |  | 12
Total current assets | 412 |  | 362
Property, plant and equipment, net | 6,367 |  | 6,022
Other assets: |  |  |
Regulatory assets | 486 |  | 498
Deferred charges and other | 76 |  | 30
Total other assets | 562 |  | 528
Total assets | $7,341 |  | $6,912

LIABILITIES AND EQUITY |  |  |
Current liabilities: |  |  |
Commercial paper | $3 |  | $257
Accounts payable | 160 |  | 154
Regulatory liabilities | 127 |  | 146
Other | 116 |  | 117
Total current liabilities | 406 |  | 674
Long-term debt, net | 2,429 |  | 2,130
Other liabilities: |  |  |
Deferred tax liabilities | 747 |  | 702
Regulatory liabilities | 514 |  | 484
Finance lease obligations - Sheboygan Falls Energy Facility | 34 |  | 42
Pension and other benefit obligations | 193 |  | 222
Other | 206 |  | 180
Total other liabilities | 1,694 |  | 1,630
Commitments and contingencies (Note 14) |  |  |
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 | 1,704 |  | 1,459
Retained earnings | 1,042 |  | 953
Total Wisconsin Power and Light Company common equity | 2,812 |  | 2,478
Total liabilities and equity | $7,341 |  | $6,912

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,
| 2021 |  | 2020
| (in millions)
Cash flows from operating activities: |  |  |
Net income | $215 |  | $220
Adjustments to reconcile net income to net cash flows from operating activities: |  |  |
Depreciation and amortization | 209 |  | 186
Deferred tax benefit and tax credits | (63) |  | (9)
Other | 12 |  | (8)
Other changes in assets and liabilities: |  |  |
Derivative assets | (116) |  | (10)
Regulatory liabilities | (5) |  | (61)
Deferred income taxes | 108 |  | 79
Other | (11) |  | 5
Net cash flows from operating activities | 349 |  | 402
Cash flows used for investing activities: |  |  |
Construction and acquisition expenditures | (487) |  | (470)
Other | (23) |  | 5
Net cash flows used for investing activities | (510) |  | (465)
Cash flows from financing activities: |  |  |
Common stock dividends | (126) |  | (127)
Capital contributions from parent | 245 |  | 25
Proceeds from issuance of long-term debt | 300 |  | 350
Payments to retire long-term debt | — |  | (150)
Net change in commercial paper | (254) |  | (29)
Other | (3) |  | (8)
Net cash flows from financing activities | 162 |  | 61
Net increase (decrease) in cash, cash equivalents and restricted cash | 1 |  | (2)
Cash, cash equivalents and restricted cash at beginning of period | 3 |  | 4
Cash, cash equivalents and restricted cash at end of period | $4 |  | $2
Supplemental cash flows information: |  |  |
Cash (paid) refunded during the period for: |  |  |
Interest | ($72) |  | ($71)
Income taxes, net | ($24) |  | $5
Significant non-cash investing and financing activities: |  |  |
Accrued capital expenditures | $59 |  | $50

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 2020 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, 2021 are not necessarily indicative of results that may be expected for the year ending December 31, 2021.
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) Asset Impairments -
Property, Plant and Equipment of Regulated Operations - In the second quarter of 2021, WPL received approval from MISO to retire Columbia Units 1 and 2, which had a net book value of approximately $470 million in aggregate as of September 30, 2021, and currently anticipates retiring Columbia Unit 1 by the end of 2023 and Columbia Unit 2 by the end of 2024. Alliant Energy and WPL concluded that Columbia Units 1 and 2 met the criteria to be considered probable of abandonment as of September 30, 2021. WPL is currently allowed a full recovery of and a full return on these EGUs from both its retail and wholesale customers, and as a result, Alliant Energy and WPL concluded that no disallowance was required as of September 30, 2021.
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, 2021 |  | December 31, 2020 |  | September 30, 2021 |  | December 31, 2020 |  | September 30, 2021 |  | December 31, 2020
Tax-related | $931 |  | $890 |  | $881 |  | $843 |  | $50 |  | $47
Pension and OPEB costs | 549 |  | 580 |  | 276 |  | 291 |  | 273 |  | 289
Asset retirement obligations | 124 |  | 119 |  | 85 |  | 81 |  | 39 |  | 38
Assets retired early | 98 |  | 113 |  | 69 |  | 77 |  | 29 |  | 36
IPL’s DAEC PPA amendment | 96 |  | 110 |  | 96 |  | 110 |  | — |  | —
WPL’s Western Wisconsin gas distribution expansion investments | 53 |  | 55 |  | — |  | — |  | 53 |  | 55
Commodity cost recovery | 32 |  | 4 |  | 17 |  | 1 |  | 15 |  | 3
Derivatives | 4 |  | 26 |  | 4 |  | 13 |  | — |  | 13
Other | 131 |  | 113 |  | 79 |  | 67 |  | 52 |  | 46
| $2,018 |  | $2,010 |  | $1,507 |  | $1,483 |  | $511 |  | $527

Commodity cost recovery - In February 2021, portions of the central and southern U.S., including Alliant Energy’s service territories, experienced a prolonged period of very cold temperatures and a series of winter storms. These events created significant volatility and increases in commodity prices caused by higher demand for electricity and natural gas and disruptions in commodity supply, resulting in IPL under-recovering its natural gas costs. In March 2021, IPL received approval from the IUB to spread recovery of these higher natural gas costs from its retail customers through December 2021. As of September 30, 2021, IPL’s cumulative under-collection of natural gas costs was $15 million. The extreme temperatures in February 2021 did not impact WPL’s natural gas costs and IPL’s and WPL’s fuel-related costs to the extent of IPL’s natural gas costs.
The cost recovery mechanism for WPL’s retail electric customers is based on forecasts of certain fuel-related costs expected to be incurred during forward-looking test periods and fuel monitoring ranges determined by the PSCW during each retail electric rate proceeding or in a separate fuel cost plan approval proceeding. In 2021, WPL’s actual fuel-related costs fell outside these fuel monitoring ranges, resulting in a $12 million deferral as of September 30, 2021.

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

| Alliant Energy |  | IPL |  | WPL
| September 30, 2021 |  | December 31, 2020 |  | September 30, 2021 |  | December 31, 2020 |  | September 30, 2021 |  | December 31, 2020
Tax-related | $611 |  | $732 |  | $313 |  | $331 |  | $298 |  | $401
Cost of removal obligations | 383 |  | 367 |  | 252 |  | 238 |  | 131 |  | 129
Derivatives | 221 |  | 28 |  | 104 |  | 25 |  | 117 |  | 3
Electric transmission cost recovery | 53 |  | 68 |  | 29 |  | 39 |  | 24 |  | 29
WPL’s West Riverside liquidated damages | 40 |  | 38 |  | — |  | — |  | 40 |  | 38
Other | 53 |  | 73 |  | 22 |  | 43 |  | 31 |  | 30
| $1,361 |  | $1,306 |  | $720 |  | $676 |  | $641 |  | $630

Tax-related - Alliant Energy’s, IPL’s and WPL’s tax-related regulatory liabilities are primarily related to excess deferred tax benefits resulting from the remeasurement of accumulated deferred income taxes caused by Federal Tax Reform. During the nine months ended September 30, 2021, Alliant Energy’s, IPL’s and WPL’s tax-related regulatory liabilities decreased primarily due to returning a portion of these excess deferred tax benefits back to customers.
NOTE 3. RECEIVABLES
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. The transfers of receivables meet the criteria for sale accounting established by the transfer of financial assets accounting rules. In April 2021, IPL amended and extended through March 2023 the purchase commitment from the third party to which it sells its receivables. Effective April 2021, the limit on cash proceeds is $110 million. As of September 30, 2021, IPL had $60 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
| 2021 |  | 2020 |  | 2021 |  | 2020
Maximum outstanding aggregate cash proceeds | $110 |  | $1 |  | $110 |  | $96
Average outstanding aggregate cash proceeds | 65 |  | 1 |  | 52 |  | 12

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

| September 30, 2021 |  | December 31, 2020
Customer accounts receivable | $145 |  | $114
Unbilled utility revenues | 83 |  | 92
Receivables sold to third party | 228 |  | 206
Less: cash proceeds | 50 |  | 1
Deferred proceeds | 178 |  | 205
Less: allowance for expected credit losses | 14 |  | 17
Fair value of deferred proceeds | $164 |  | $188

As of September 30, 2021, outstanding receivables past due under the Receivables Agreement were $19 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
| 2021 |  | 2020 |  | 2021 |  | 2020
Collections | $607 |  | $561 |  | $1,589 |  | $1,555
Write-offs, net of recoveries | 4 |  | 1 |  | 7 |  | 4

NOTE 4. 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
| 2021 |  | 2020 |  | 2021 |  | 2020
ATC Holdings | ($12) |  | ($11) |  | ($34) |  | ($36)
Other | (1) |  | (4) |  | (13) |  | (10)
| ($13) |  | ($15) |  | ($47) |  | ($46)

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NOTE 5. COMMON EQUITY
Common Share Activity - A summary of Alliant Energy’s common stock activity was as follows:

Shares outstanding, January 1, 2021 | 249,868,415 |
Shareowner Direct Plan | 378,823 |
Equity-based compensation plans | 113,549 |
Shares outstanding, September 30, 2021 | 250,360,787 |

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 |  | Cumulative |  |
|  |  | Additional |  |  |  | Other |  | Deferred |  | Preferred |  |
| Common |  | Paid-In |  | Retained |  | Comprehensive |  | Compensation |  | Stock |  | Total
| Stock |  | Capital |  | Earnings |  | Income (Loss) |  | Trust |  | of IPL |  | Equity
Three Months Ended September 30, 2021 |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning balance, June 30, 2021 | $3 |  | $2,722 |  | $3,106 |  | ($1) |  | ($11) |  | $200 |  | $6,019
Net income attributable to Alliant Energy common shareowners |  |  |  |  | 256 |  |  |  |  |  |  |  | 256
Common stock dividends ($0.4025 per share) |  |  |  |  | (101) |  |  |  |  |  |  |  | (101)
Shareowner Direct Plan issuances |  |  | 6 |  |  |  |  |  |  |  |  |  | 6
Equity-based compensation plans and other |  |  | 5 |  |  |  |  |  |  |  |  |  | 5
Ending balance, September 30, 2021 | $3 |  | $2,733 |  | $3,261 |  | ($1) |  | ($11) |  | $200 |  | $6,185
Three Months Ended September 30, 2020 |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning balance, June 30, 2020 | $2 |  | $2,683 |  | $2,874 |  | ($1) |  | ($10) |  | $200 |  | $5,748
Net income attributable to Alliant Energy common shareowners |  |  |  |  | 246 |  |  |  |  |  |  |  | 246
Common stock dividends ($0.38 per share) |  |  |  |  | (94) |  |  |  |  |  |  |  | (94)
Shareowner Direct Plan issuances |  |  | 6 |  |  |  |  |  |  |  |  |  | 6
Equity-based compensation plans and other |  |  | 4 |  |  |  |  |  | (1) |  |  |  | 3
Ending balance, September 30, 2020 | $2 |  | $2,693 |  | $3,026 |  | ($1) |  | ($11) |  | $200 |  | $5,909

Alliant Energy | Total Alliant Energy Common Equity |  |  |  |
|  |  |  |  |  |  | Accumulated |  | Shares in |  | Cumulative |  |
|  |  | Additional |  |  |  | Other |  | Deferred |  | Preferred |  |
| Common |  | Paid-In |  | Retained |  | Comprehensive |  | Compensation |  | Stock |  | Total
| Stock |  | Capital |  | Earnings |  | Income (Loss) |  | Trust |  | of IPL |  | Equity
Nine Months Ended September 30, 2021 |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2020 | $2 |  | $2,704 |  | $2,994 |  | ($1) |  | ($11) |  | $200 |  | $5,888
Net income attributable to Alliant Energy common shareowners |  |  |  |  | 571 |  |  |  |  |  |  |  | 571
Common stock dividends ($1.2075 per share) |  |  |  |  | (304) |  |  |  |  |  |  |  | (304)
Shareowner Direct Plan issuances | 1 |  | 21 |  |  |  |  |  |  |  |  |  | 22
Equity-based compensation plans and other |  |  | 8 |  |  |  |  |  |  |  |  |  | 8
Ending balance, September 30, 2021 | $3 |  | $2,733 |  | $3,261 |  | ($1) |  | ($11) |  | $200 |  | $6,185
Nine Months Ended September 30, 2020 |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2019 | $2 |  | $2,446 |  | $2,766 |  | $1 |  | ($10) |  | $200 |  | $5,405
Net income attributable to Alliant Energy common shareowners |  |  |  |  | 550 |  |  |  |  |  |  |  | 550
Common stock dividends ($1.14 per share) |  |  |  |  | (281) |  |  |  |  |  |  |  | (281)
Equity forward settlements and Shareowner Direct Plan issuances |  |  | 241 |  |  |  |  |  |  |  |  |  | 241
Equity-based compensation plans and other |  |  | 6 |  |  |  |  |  | (1) |  |  |  | 5
Adoption of new accounting standard, net of tax |  |  |  |  | (9) |  |  |  |  |  |  |  | (9)
Other comprehensive loss, net of tax |  |  |  |  |  |  | (2) |  |  |  |  |  | (2)
Ending balance, September 30, 2020 | $2 |  | $2,693 |  | $3,026 |  | ($1) |  | ($11) |  | $200 |  | $5,909

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IPL | Total IPL Common Equity |  |  |  |
|  |  | Additional |  |  |  | Cumulative |  |
| Common |  | Paid-In |  | Retained |  | Preferred |  | Total
| Stock |  | Capital |  | Earnings |  | Stock |  | Equity
Three Months Ended September 30, 2021 |  |  |  |  |  |  |  |  |
Beginning balance, June 30, 2021 | $33 |  | $2,802 |  | $944 |  | $200 |  | $3,979
Net income available for common stock |  |  |  |  | 157 |  |  |  | 157
Common stock dividends |  |  |  |  | (101) |  |  |  | (101)
Ending balance, September 30, 2021 | $33 |  | $2,802 |  | $1,000 |  | $200 |  | $4,035
Three Months Ended September 30, 2020 |  |  |  |  |  |  |  |  |
Beginning balance, June 30, 2020 | $33 |  | $2,523 |  | $915 |  | $200 |  | $3,671
Net income available for common stock |  |  |  |  | 148 |  |  |  | 148
Common stock dividends |  |  |  |  | (59) |  |  |  | (59)
Capital contributions from parent |  |  | 170 |  |  |  |  |  | 170
Ending balance, September 30, 2020 | $33 |  | $2,693 |  | $1,004 |  | $200 |  | $3,930

IPL | Total IPL Common Equity |  |  |  |
|  |  | Additional |  |  |  | Cumulative |  |
| Common |  | Paid-In |  | Retained |  | Preferred |  | Total
| Stock |  | Capital |  | Earnings |  | Stock |  | Equity
Nine Months Ended September 30, 2021 |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2020 | $33 |  | $2,752 |  | $979 |  | $200 |  | $3,964
Net income available for common stock |  |  |  |  | 322 |  |  |  | 322
Common stock dividends |  |  |  |  | (301) |  |  |  | (301)
Capital contributions from parent |  |  | 50 |  |  |  |  |  | 50
Ending balance, September 30, 2021 | $33 |  | $2,802 |  | $1,000 |  | $200 |  | $4,035
Nine Months Ended September 30, 2020 |  |  |  |  |  |  |  |  |
Beginning balance, December 31, 2019 | $33 |  | $2,348 |  | $891 |  | $200 |  | $3,472
Net income available for common stock |  |  |  |  | 290 |  |  |  | 290
Common stock dividends |  |  |  |  | (177) |  |  |  | (177)
Capital contributions from parent |  |  | 345 |  |  |  |  |  | 345
Ending balance, September 30, 2020 | $33 |  | $2,693 |  | $1,004 |  | $200 |  | $3,930

WPL |  |  | Additional |  |  |  | Total
| Common |  | Paid-In |  | Retained |  | Common
| Stock |  | Capital |  | Earnings |  | Equity
Three Months Ended September 30, 2021 |  |  |  |  |  |  |
Beginning balance, June 30, 2021 | $66 |  | $1,669 |  | $990 |  | $2,725
Net income |  |  |  |  | 93 |  | 93
Common stock dividends |  |  |  |  | (41) |  | (41)
Capital contributions from parent |  |  | 35 |  |  |  | 35
Ending balance, September 30, 2021 | $66 |  | $1,704 |  | $1,042 |  | $2,812
Three Months Ended September 30, 2020 |  |  |  |  |  |  |
Beginning balance, June 30, 2020 | $66 |  | $1,459 |  | $927 |  | $2,452
Net income |  |  |  |  | 73 |  | 73
Common stock dividends |  |  |  |  | (43) |  | (43)
Ending balance, September 30, 2020 | $66 |  | $1,459 |  | $957 |  | $2,482

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WPL |  |  | Additional |  |  |  | Total
| Common |  | Paid-In |  | Retained |  | Common
| Stock |  | Capital |  | Earnings |  | Equity
Nine Months Ended September 30, 2021 |  |  |  |  |  |  |
Beginning balance, December 31, 2020 | $66 |  | $1,459 |  | $953 |  | $2,478
Net income |  |  |  |  | 215 |  | 215
Common stock dividends |  |  |  |  | (126) |  | (126)
Capital contributions from parent |  |  | 245 |  |  |  | 245
Ending balance, September 30, 2021 | $66 |  | $1,704 |  | $1,042 |  | $2,812
Nine Months Ended September 30, 2020 |  |  |  |  |  |  |
Beginning balance, December 31, 2019 | $66 |  | $1,434 |  | $864 |  | $2,364
Net income |  |  |  |  | 220 |  | 220
Common stock dividends |  |  |  |  | (127) |  | (127)
Capital contributions from parent |  |  | 25 |  |  |  | 25
Ending balance, September 30, 2020 | $66 |  | $1,459 |  | $957 |  | $2,482

NOTE 6. PREFERRED STOCK
In November 2021, IPL announced it will redeem all 8,000,000 outstanding shares of its 5.1% cumulative preferred stock in December 2021 at par value for approximately $200 million plus accrued and unpaid dividends up to the redemption date.
NOTE 7. DEBT
NOTE 7(a) Short-term Debt - In the third quarter of 2021, Alliant Energy, IPL and WPL reallocated credit facility capacity amounts to $500 million for Alliant Energy at the parent company level, $100 million for IPL and $400 million for WPL, within the $1 billion total commitment. Information regarding Alliant Energy’s, IPL’s and WPL’s commercial paper, and Alliant Energy’s and WPL’s borrowings under the single credit facility, which currently expires in August 2023, classified as short-term debt was as follows (dollars in millions):

September 30, 2021 | Alliant Energy |  | IPL |  | WPL
Amount outstanding | $316 |  | $— |  | $3
Weighted average interest rates | 0.2% |  | N/A |  | 0.1%
Available credit facility capacity | $684 |  | $100 |  | $397

| Alliant Energy |  | IPL |  | WPL
Three Months Ended September 30 | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Maximum amount outstanding (based on daily outstanding balances) | $648 |  | $422 |  | $8 |  | $— |  | $320 |  | $139
Average amount outstanding (based on daily outstanding balances) | $560 |  | $252 |  | $— |  | $— |  | $221 |  | $83
Weighted average interest rates | 0.2% |  | 0.2% |  | 0.2% |  | N/A |  | 0.1% |  | 0.2%
Nine Months Ended September 30 |  |  |  |  |  |  |  |  |  |  |
Maximum amount outstanding (based on daily outstanding balances) | $648 |  | $463 |  | $19 |  | $8 |  | $320 |  | $212
Average amount outstanding (based on daily outstanding balances) | $479 |  | $252 |  | $— |  | $— |  | $196 |  | $86
Weighted average interest rates | 0.2% |  | 1.1% |  | 0.2% |  | 0.5% |  | 0.1% |  | 1.2%

NOTE 7(b) Long-term Debt - In September 2021, WPL issued $300 million of 1.95% debentures due 2031. The debentures were issued as green bonds, and an amount equal to or in excess of the net proceeds will be disbursed for the construction and development of WPL’s wind and solar EGUs.

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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 | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Electric Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | $348 |  | $328 |  | $207 |  | $189 |  | $141 |  | $139
Retail - commercial | 232 |  | 210 |  | 160 |  | 142 |  | 72 |  | 68
Retail - industrial | 265 |  | 241 |  | 158 |  | 149 |  | 107 |  | 92
Wholesale | 55 |  | 47 |  | 18 |  | 17 |  | 37 |  | 30
Bulk power and other | 39 |  | 26 |  | 12 |  | 22 |  | 27 |  | 4
Total Electric Utility | 939 |  | 852 |  | 555 |  | 519 |  | 384 |  | 333
Gas Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | 24 |  | 22 |  | 14 |  | 12 |  | 10 |  | 10
Retail - commercial | 13 |  | 10 |  | 8 |  | 6 |  | 5 |  | 4
Retail - industrial | 3 |  | 2 |  | 3 |  | 1 |  | — |  | 1
Transportation/other | 10 |  | 8 |  | 6 |  | 5 |  | 4 |  | 3
Total Gas Utility | 50 |  | 42 |  | 31 |  | 24 |  | 19 |  | 18
Other Utility: |  |  |  |  |  |  |  |  |  |  |
Steam | 9 |  | 8 |  | 9 |  | 8 |  | — |  | —
Other utility | 4 |  | 2 |  | 4 |  | 2 |  | — |  | —
Total Other Utility | 13 |  | 10 |  | 13 |  | 10 |  | — |  | —
Non-Utility and Other: |  |  |  |  |  |  |  |  |  |  |
Travero and other | 22 |  | 16 |  | — |  | — |  | — |  | —
Total Non-Utility and Other | 22 |  | 16 |  | — |  | — |  | — |  | —
Total revenues | $1,024 |  | $920 |  | $599 |  | $553 |  | $403 |  | $351

| Alliant Energy |  | IPL |  | WPL
Nine Months Ended September 30 | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Electric Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | $868 |  | $845 |  | $488 |  | $472 |  | $380 |  | $373
Retail - commercial | 579 |  | 556 |  | 385 |  | 371 |  | 194 |  | 185
Retail - industrial | 677 |  | 648 |  | 386 |  | 384 |  | 291 |  | 264
Wholesale | 142 |  | 127 |  | 44 |  | 44 |  | 98 |  | 83
Bulk power and other | 91 |  | 81 |  | 40 |  | 61 |  | 51 |  | 20
Total Electric Utility | 2,357 |  | 2,257 |  | 1,343 |  | 1,332 |  | 1,014 |  | 925
Gas Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | 162 |  | 146 |  | 90 |  | 79 |  | 72 |  | 67
Retail - commercial | 85 |  | 70 |  | 47 |  | 38 |  | 38 |  | 32
Retail - industrial | 11 |  | 8 |  | 8 |  | 5 |  | 3 |  | 3
Transportation/other | 31 |  | 29 |  | 20 |  | 19 |  | 11 |  | 10
Total Gas Utility | 289 |  | 253 |  | 165 |  | 141 |  | 124 |  | 112
Other Utility: |  |  |  |  |  |  |  |  |  |  |
Steam | 27 |  | 27 |  | 27 |  | 27 |  | — |  | —
Other utility | 9 |  | 5 |  | 8 |  | 4 |  | 1 |  | 1
Total Other Utility | 36 |  | 32 |  | 35 |  | 31 |  | 1 |  | 1
Non-Utility and Other: |  |  |  |  |  |  |  |  |  |  |
Travero and other | 60 |  | 57 |  | — |  | — |  | — |  | —
Total Non-Utility and Other | 60 |  | 57 |  | — |  | — |  | — |  | —
Total revenues | $2,742 |  | $2,599 |  | $1,543 |  | $1,504 |  | $1,139 |  | $1,038

NOTE 9. INCOME TAXES
Income Tax Rates - Overall effective income tax rates, 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. The decreases in Alliant Energy’s and WPL’s overall effective income tax rates for the three and nine months ended September 30, 2021 compared to the same periods in 2020 were primarily due to increased amortization of excess deferred taxes primarily at WPL, which were used to offset increases in WPL’s 2021 increased revenue requirements.

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| Alliant Energy |  | IPL |  | WPL
| Three Months |  | Nine Months |  | Three Months |  | Nine Months |  | Three Months |  | Nine Months
| 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Overall income tax rate | (9%) |  | (9%) |  | (13%) |  | (9%) |  | (8%) |  | (14%) |  | (11%) |  | (14%) |  | (19%) |  | (7%) |  | (24%) |  | (8%)

Deferred Tax Assets and Liabilities -
Carryforwards - At September 30, 2021, carryforwards and expiration dates were estimated as follows (in millions):

| Range of Expiration Dates |  | Alliant Energy |  | IPL |  | WPL
Federal net operating losses | 2037 |  | $170 |  | $157 |  | $1
State net operating losses | 2021-2041 |  | 592 |  | 24 |  | 2
Federal tax credits | 2022-2041 |  | 547 |  | 339 |  | 186

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 | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Service cost | $2 |  | $3 |  | $8 |  | $8 |  | $1 |  | $1 |  | $3 |  | $3
Interest cost | 9 |  | 10 |  | 26 |  | 32 |  | 1 |  | 2 |  | 3 |  | 5
Expected return on plan assets | (17) |  | (17) |  | (51) |  | (52) |  | (1) |  | (1) |  | (3) |  | (4)
Amortization of prior service credit | (1) |  | — |  | (1) |  | — |  | — |  | — |  | — |  | —
Amortization of actuarial loss | 10 |  | 9 |  | 29 |  | 26 |  | 1 |  | — |  | 3 |  | 2
Settlement losses (a) | — |  | — |  | — |  | 4 |  | — |  | — |  | — |  | —
| $3 |  | $5 |  | $11 |  | $18 |  | $2 |  | $2 |  | $6 |  | $6

| Defined Benefit Pension Plans |  | OPEB Plans
| Three Months |  | Nine Months |  | Three Months |  | Nine Months
IPL | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Service cost | $1 |  | $2 |  | $5 |  | $5 |  | $— |  | $— |  | $1 |  | $1
Interest cost | 4 |  | 5 |  | 12 |  | 15 |  | 1 |  | 1 |  | 2 |  | 2
Expected return on plan assets | (8) |  | (8) |  | (24) |  | (24) |  | (1) |  | (1) |  | (3) |  | (3)
Amortization of actuarial loss | 5 |  | 4 |  | 13 |  | 11 |  | — |  | — |  | 1 |  | 1
| $2 |  | $3 |  | $6 |  | $7 |  | $— |  | $— |  | $1 |  | $1

| Defined Benefit Pension Plans |  | OPEB Plans
| Three Months |  | Nine Months |  | Three Months |  | Nine Months
WPL | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Service cost | $1 |  | $1 |  | $3 |  | $3 |  | $1 |  | $— |  | $1 |  | $1
Interest cost | 3 |  | 5 |  | 11 |  | 14 |  | — |  | 1 |  | 1 |  | 2
Expected return on plan assets | (8) |  | (8) |  | (23) |  | (23) |  | — |  | (1) |  | — |  | (1)
Amortization of actuarial loss | 5 |  | 4 |  | 14 |  | 12 |  | 1 |  | 1 |  | 2 |  | 2
| $1 |  | $2 |  | $5 |  | $6 |  | $2 |  | $1 |  | $4 |  | $4

(a)Settlement losses related to payments made to retired executives of Alliant Energy.
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
| 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Compensation expense | $4 |  | $5 |  | $9 |  | $10 |  | $2 |  | $3 |  | $5 |  | $6 |  | $2 |  | $2 |  | $4 |  | $4
Income tax benefits | 1 |  | 1 |  | 3 |  | 3 |  | — |  | 1 |  | 1 |  | 2 |  | — |  | — |  | 1 |  | 1

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As of September 30, 2021, Alliant Energy’s, IPL’s and WPL’s total unrecognized compensation cost related to share-based compensation awards was $7 million, $4 million and $3 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, 2021, performance shares, performance restricted stock units and restricted stock units were granted to key employees 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 | 73,112 |  | $46.19
Performance restricted stock units | 73,112 |  | 48.66
Restricted stock units | 80,152 |  | 48.65

As of September 30, 2021, 491,406 shares were included in the calculation of diluted EPS related to the nonvested equity awards.
NOTE 11. ASSET RETIREMENT OBLIGATIONS
A reconciliation of the changes in asset retirement obligations associated with long-lived assets for the nine months ended September 30, 2021 is as follows (in millions):

| Alliant Energy |  | IPL |  |
Balance, January 1 | $251 |  | $177 |  |
Revisions in estimated cash flows | 37 |  | 32 |  |
Liabilities settled | (10) |  | (8) |  |
Liabilities incurred | 1 |  | — |  |
Accretion expense | 6 |  | 4 |  |
Balance, September 30 | $285 |  | $205 |  |

NOTE 12. DERIVATIVE INSTRUMENTS
Commodity Derivatives -
Notional Amounts - As of September 30, 2021, 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):

|  |  | FTRs |  | Natural Gas |  | Coal |  | Diesel Fuel
|  |  |  |  | MWhs |  | Years |  | Dths |  | Years |  | Tons |  | Years |  | Gallons |  | Years
Alliant Energy |  |  |  |  | 13,265 |  |  | 2021-2022 |  | 189,332 |  |  | 2021-2030 |  | 4,280 |  |  | 2021-2023 |  | 3,654 |  |  | 2021-2022
IPL |  |  |  |  | 4,014 |  |  | 2021-2022 |  | 103,859 |  |  | 2021-2030 |  | 1,807 |  |  | 2021-2023 |  | — |  |  | —
WPL |  |  |  |  | 9,251 |  |  | 2021-2022 |  | 85,473 |  |  | 2021-2030 |  | 2,473 |  |  | 2021-2023 |  | 3,654 |  |  | 2021-2022

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, 2021 |  | December 31, 2020 |  | September 30, 2021 |  | December 31, 2020 |  | September 30, 2021 |  | December 31, 2020
Current derivative assets | $158 |  | $24 |  | $72 |  | $20 |  | $86 |  | $4
Non-current derivative assets | 78 |  | 10 |  | 43 |  | 9 |  | 35 |  | 1
Current derivative liabilities | 3 |  | 9 |  | 3 |  | 3 |  | — |  | 6
Non-current derivative liabilities | 1 |  | 16 |  | 1 |  | 9 |  | — |  | 7

During the nine months ended September 30, 2021, Alliant Energy’s, IPL’s and WPL’s derivative assets increased and derivative liabilities decreased primarily as a result of higher natural gas prices. Based on IPL’s and WPL’s natural gas cost recovery mechanisms, this resulted in corresponding decreases in derivative regulatory assets and increases in derivative regulatory 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 in the form of letters of credit or cash collateral 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, 2021 and December 31, 2020, 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 would be required to be posted as credit support to counterparties by Alliant Energy, IPL

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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, amounts would not be materially different from gross amounts of derivative assets and derivative liabilities at September 30, 2021 and December 31, 2020. 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.
NOTE 13. 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, 2021 |  | December 31, 2020
|  |  | 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 | $9 |  |  | $9 |  |  | $— |  |  | $— |  |  | $9 |  |  | $44 |  |  | $44 |  |  | $— |  |  | $— |  |  | $44 |
Derivatives | 236 |  |  | — |  |  | 207 |  |  | 29 |  |  | 236 |  |  | 34 |  |  | — |  |  | 5 |  |  | 29 |  |  | 34 |
Deferred proceeds | 164 |  |  | — |  |  | — |  |  | 164 |  |  | 164 |  |  | 188 |  |  | — |  |  | — |  |  | 188 |  |  | 188 |
Liabilities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivatives | 4 |  |  | — |  |  | 4 |  |  | — |  |  | 4 |  |  | 25 |  |  | — |  |  | 25 |  |  | — |  |  | 25 |
Long-term debt (incl. current maturities) | 7,075 |  |  | — |  |  | 8,083 |  |  | 1 |  |  | 8,084 |  |  | 6,777 |  |  | — |  |  | 8,107 |  |  | 2 |  |  | 8,109 |

IPL | September 30, 2021 |  | December 31, 2020
|  |  | 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 | $9 |  |  | $9 |  |  | $— |  |  | $— |  |  | $9 |  |  | $44 |  |  | $44 |  |  | $— |  |  | $— |  |  | $44 |
Derivatives | 115 |  |  | — |  |  | 96 |  |  | 19 |  |  | 115 |  |  | 29 |  |  | — |  |  | 3 |  |  | 26 |  |  | 29 |
Deferred proceeds | 164 |  |  | — |  |  | — |  |  | 164 |  |  | 164 |  |  | 188 |  |  | — |  |  | — |  |  | 188 |  |  | 188 |
Liabilities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivatives | 4 |  |  | — |  |  | 4 |  |  | — |  |  | 4 |  |  | 12 |  |  | — |  |  | 12 |  |  | — |  |  | 12 |
Long-term debt | 3,347 |  |  | — |  |  | 3,849 |  |  | — |  |  | 3,849 |  |  | 3,345 |  |  | — |  |  | 4,021 |  |  | — |  |  | 4,021 |

WPL | September 30, 2021 |  | December 31, 2020
|  |  | Fair Value |  |  |  | Fair Value
| Carrying |  | Level |  | Level |  | Level |  |  |  | Carrying |  | Level |  | Level |  | Level |  |
| Amount |  | 1 |  | 2 |  | 3 |  | Total |  | Amount |  | 1 |  | 2 |  | 3 |  | Total
Assets: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivatives | $121 |  |  | $— |  |  | $111 |  |  | $10 |  |  | $121 |  |  | $5 |  |  | $— |  |  | $2 |  |  | $3 |  |  | $5 |
Liabilities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivatives | — |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 13 |  |  | — |  |  | 13 |  |  | — |  |  | 13 |
Long-term debt | 2,429 |  |  | — |  |  | 2,869 |  |  | — |  |  | 2,869 |  |  | 2,130 |  |  | — |  |  | 2,690 |  |  | — |  |  | 2,690 |

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Information for Alliant Energy’s and IPL’s fair value measurements using significant unobservable inputs (Level 3 inputs) was as follows (in millions). Such amounts for WPL were not material.

Alliant Energy | Commodity Contract Derivative |  |
| Assets and (Liabilities), net |  | Deferred Proceeds
Three Months Ended September 30 | 2021 |  | 2020 |  | 2021 |  | 2020
Beginning balance, July 1 | $39 |  | $36 |  | $154 |  | $194
Total net gains included in changes in net assets (realized/unrealized) | 5 |  | — |  | — |  | —
Transfers out of Level 3 | (8) |  | — |  | — |  | —
Sales | — |  | (1) |  | — |  | —
Settlements (a) | (7) |  | (5) |  | 10 |  | 7
Ending balance, September 30 | $29 |  | $30 |  | $164 |  | $201
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 | $5 |  | ($1) |  | $— |  | $—

Alliant Energy | Commodity Contract Derivative |  |
| Assets and (Liabilities), net |  | Deferred Proceeds
Nine Months Ended September 30 | 2021 |  | 2020 |  | 2021 |  | 2020
Beginning balance, January 1 | $29 |  | $21 |  | $188 |  | $188
Total net gains included in changes in net assets (realized/unrealized) | 6 |  | 8 |  | — |  | —
Transfers out of Level 3 | (8) |  | — |  | — |  | —
Purchases | 21 |  | 14 |  | — |  | —
Sales | — |  | (1) |  | — |  | —
Settlements (a) | (19) |  | (12) |  | (24) |  | 13
Ending balance, September 30 | $29 |  | $30 |  | $164 |  | $201
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 | $6 |  | $8 |  | $— |  | $—

IPL | Commodity Contract Derivative |  |
| Assets and (Liabilities), net |  | Deferred Proceeds
Three Months Ended September 30 | 2021 |  | 2020 |  | 2021 |  | 2020
Beginning balance, July 1 | $30 |  | $32 |  | $154 |  | $194
Total net gains (losses) included in changes in net assets (realized/unrealized) | 2 |  | (1) |  | — |  | —
Transfers out of Level 3 | (8) |  | — |  | — |  | —
Sales | — |  | (1) |  | — |  | —
Settlements (a) | (5) |  | (4) |  | 10 |  | 7
Ending balance, September 30 | $19 |  | $26 |  | $164 |  | $201
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 | $2 |  | ($1) |  | $— |  | $—

IPL | Commodity Contract Derivative |  |
| Assets and (Liabilities), net |  | Deferred Proceeds
Nine Months Ended September 30 | 2021 |  | 2020 |  | 2021 |  | 2020
Beginning balance, January 1 | $26 |  | $18 |  | $188 |  | $188
Total net gains included in changes in net assets (realized/unrealized) | — |  | 7 |  | — |  | —
Transfers out of Level 3 | (8) |  | — |  | — |  | —
Purchases | 16 |  | 11 |  | — |  | —
Sales | — |  | (1) |  | — |  | —
Settlements (a) | (15) |  | (9) |  | (24) |  | 13
Ending balance, September 30 | $19 |  | $26 |  | $164 |  | $201
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 | $— |  | $7 |  | $— |  | $—

(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.

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Commodity Contracts - The fair value of FTR and natural gas commodity contracts categorized as Level 3 was recognized as net derivative assets as follows (in millions):

| Alliant Energy |  | IPL |  | WPL
| Excluding FTRs |  | FTRs |  | Excluding FTRs |  | FTRs |  | Excluding FTRs |  | FTRs
September 30, 2021 | $7 |  | $22 |  | $5 |  | $14 |  | $2 |  | $8
December 31, 2020 | 18 |  | 11 |  | 17 |  | 9 |  | 1 |  | 2

NOTE 14. COMMITMENTS AND CONTINGENCIES
NOTE 14(a) Capital Purchase Commitments - Various contractual obligations contain minimum future commitments related to capital expenditures for certain construction projects, including WPL’s expansion of solar generation. At September 30, 2021, Alliant Energy’s and WPL’s minimum future commitments for these projects were $95 million and $93 million, respectively.
NOTE 14(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, 2021, related minimum future commitments were as follows (in millions):

| Alliant Energy |  | IPL |  | WPL
Natural gas | $985 |  | $514 |  | $471
Coal | 82 |  | 54 |  | 28
Other (a) | 134 |  | 71 |  | 39
| $1,201 |  | $639 |  | $538

(a)Includes individual commitments incurred during the normal course of business that exceeded $1 million at September 30, 2021.
NOTE 14(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, 2021, the currently known partnership obligations for the abandonment obligations are estimated at $68 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 $68 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, 2021 and December 31, 2020, 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.
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 $67 million as of September 30, 2021 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, 2021 and December 31, 2020.
NOTE 14(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, 2021, 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). At September 30, 2021, such amounts for WPL were not material.

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| Alliant Energy |  | IPL
Range of estimated future costs | $9 |  | - | $24 |  | $6 |  | - | $19
Current and non-current environmental liabilities | $12 |  | $9

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 Burlington by December 31, 2021 and 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: 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 15. 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, 2021 |  |  |  |  |  |  |  |  |  |  |
Revenues | $939 |  | $50 |  | $13 |  | $1,002 |  | $22 |  | $1,024
Operating income (loss) | 290 |  | (5) |  | (5) |  | 280 |  | 9 |  | 289
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 250 |  | 6 |  | 256
Three Months Ended September 30, 2020 |  |  |  |  |  |  |  |  |  |  |
Revenues | $852 |  | $42 |  | $10 |  | $904 |  | $16 |  | $920
Operating income (loss) | 251 |  | (1) |  | 1 |  | 251 |  | 21 |  | 272
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 221 |  | 25 |  | 246

Alliant Energy |  |  |  |  |  |  |  |  | ATC Holdings, |  | Alliant
| Utility |  | Non-Utility, |  | Energy
| Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
| (in millions)
Nine Months Ended September 30, 2021 |  |  |  |  |  |  |  |  |  |  |
Revenues | $2,357 |  | $289 |  | $36 |  | $2,682 |  | $60 |  | $2,742
Operating income (loss) | 601 |  | 42 |  | (4) |  | 639 |  | 24 |  | 663
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 537 |  | 34 |  | 571
Nine Months Ended September 30, 2020 |  |  |  |  |  |  |  |  |  |  |
Revenues | $2,257 |  | $253 |  | $32 |  | $2,542 |  | $57 |  | $2,599
Operating income | 549 |  | 48 |  | 5 |  | 602 |  | 26 |  | 628
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 510 |  | 40 |  | 550

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IPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended September 30, 2021 |  |  |  |  |  |  |
Revenues | $555 |  | $31 |  | $13 |  | $599
Operating income (loss) | 186 |  | (3) |  | (3) |  | 180
Net income available for common stock |  |  |  |  |  |  | 157
Three Months Ended September 30, 2020 |  |  |  |  |  |  |
Revenues | $519 |  | $24 |  | $10 |  | $553
Operating income | 159 |  | 1 |  | 2 |  | 162
Net income available for common stock |  |  |  |  |  |  | 148
Nine Months Ended September 30, 2021 |  |  |  |  |  |  |
Revenues | $1,343 |  | $165 |  | $35 |  | $1,543
Operating income (loss) | 365 |  | 30 |  | (1) |  | 394
Net income available for common stock |  |  |  |  |  |  | 322
Nine Months Ended September 30, 2020 |  |  |  |  |  |  |
Revenues | $1,332 |  | $141 |  | $31 |  | $1,504
Operating income | 308 |  | 34 |  | 5 |  | 347
Net income available for common stock |  |  |  |  |  |  | 290

WPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended September 30, 2021 |  |  |  |  |  |  |
Revenues | $384 |  | $19 |  | $— |  | $403
Operating income (loss) | 104 |  | (2) |  | (2) |  | 100
Net income |  |  |  |  |  |  | 93
Three Months Ended September 30, 2020 |  |  |  |  |  |  |
Revenues | $333 |  | $18 |  | $— |  | $351
Operating income (loss) | 92 |  | (2) |  | (1) |  | 89
Net income |  |  |  |  |  |  | 73
Nine Months Ended September 30, 2021 |  |  |  |  |  |  |
Revenues | $1,014 |  | $124 |  | $1 |  | $1,139
Operating income (loss) | 236 |  | 12 |  | (3) |  | 245
Net income |  |  |  |  |  |  | 215
Nine Months Ended September 30, 2020 |  |  |  |  |  |  |
Revenues | $925 |  | $112 |  | $1 |  | $1,038
Operating income | 241 |  | 14 |  | — |  | 255
Net income |  |  |  |  |  |  | 220

NOTE 16. 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
| 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Corporate Services billings | $50 |  | $53 |  | $138 |  | $134 |  | $37 |  | $41 |  | $113 |  | $108
Sales credited | 4 |  | 10 |  | 9 |  | 35 |  | 16 |  | — |  | 23 |  | 4
Purchases billed | 105 |  | 110 |  | 347 |  | 248 |  | 24 |  | 39 |  | 71 |  | 79

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

| IPL |  | WPL
| September 30, 2021 |  | December 31, 2020 |  | September 30, 2021 |  | December 31, 2020
Net payables to Corporate Services | $109 |  | $110 |  | $80 |  | $73

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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
| 2021 |  | 2020 |  | 2021 |  | 2020
ATC billings to WPL | $29 |  | $27 |  | $91 |  | $80
WPL billings to ATC | 4 |  | 2 |  | 13 |  | 8

WPL owed ATC net amounts of $8 million as of September 30, 2021 and $9 million as of December 31, 2020.
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 2020 Form 10-K. Unless otherwise noted, all “per share” references in MDA refer to earnings per diluted share.
2021 HIGHLIGHTS
Key highlights since the filing of the 2020 Form 10-K include the following:
Customer Investments (refer to “Customer Investments” for details):
•In March 2021, WPL filed its second Certificate of Authority with the PSCW for approval to acquire, construct, own, and operate up to 414 MW of new solar generation in various Wisconsin counties.
•In June 2021, WPL received an order from the PSCW for its first Certificate of Authority authorizing WPL to acquire, own and operate 675 MW of new solar generation in various Wisconsin counties.
•In November 2021, IPL filed for advance rate-making principles with the IUB for up to 400 MW of new solar generation and up to 75 MW of new battery storage.
Rate Matters:
•In May 2021, WPL filed a proposed settlement with the PSCW for annual base rate increases of $70 million and $15 million for WPL’s retail electric and gas customers, respectively, covering the 2022/2023 forward-looking Test Period, which was based on a stipulated agreement between WPL and certain intervenor groups. In November 2021, WPL filed updated information with the PSCW to reflect anticipated increases in retail fuel-related costs in 2022. As a result, annual rates for WPL’s retail electric customers are currently expected to increase by an additional $45 million in 2022, for a total of $115 million. The key drivers for the proposed annual base rate increases include lower excess deferred income tax benefits in 2022 and 2023 and revenue requirement impacts of increasing electric and gas rate base, including investments in solar generation. In addition, the settlement proposes WPL maintain its current authorized return on common equity of 10%, implement a 54% common equity component of regulatory capital structure, as well as receive a recovery of and a return on the remaining net book value of Edgewater Unit 5, which is currently expected to be retired by the end of 2022. WPL currently expects any rate changes granted from this request to be effective on January 1, 2022 and extend through the end of 2023.
•In June 2021, the IUB adopted new rules that establish minimum filing requirements for rate reviews using a forward-looking test period, and the related subsequent proceeding review after the close of the forward-looking test period. The rules provide that in the subsequent proceeding review, a utility’s actual costs and revenues shall be presumed to be reasonably consistent with the forward-looking test period if the utility’s actual return on common equity falls within a standard of reasonableness of 50 basis points above to 50 basis points below the authorized return on common equity. If the utility’s actual return on common equity is outside of this range, future rates could be adjusted.
•In August 2021, the IUB issued an order for IPL’s 2020 forward-looking Test Period gas subsequent proceeding, authorizing IPL to maintain its current retail gas rates.
•In November 2021, the IUB issued an order for IPL’s 2020 forward-looking Test Period electric subsequent proceeding, authorizing IPL to maintain its current retail electric rates.
Legislative Matters:
•In March 2021, the American Rescue Plan Act of 2021 (Act) was enacted. The most significant provision of the Act for Alliant Energy is reduced minimum pension plan funding requirements, which Alliant Energy adopted in August 2021. The Act also provides additional funding to the Low Income Home Energy Assistance Program, which assists certain of Alliant Energy’s customers with managing their energy costs, as well as provides financial support for certain of Alliant Energy’s residential, small business and non-profit customers.
•In April 2021, legislation was enacted in Iowa prohibiting counties and cities from regulating the sale of natural gas and propane, which supports IPL’s ability to provide gas utility service to a diversified base of retail customers and industries.

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Financings and Common Stock Dividends:
•In September 2021, WPL issued $300 million of 1.95% debentures due 2031. The debentures were issued as green bonds, and an amount equal to or in excess of the net proceeds will be disbursed for the construction and development of WPL’s wind and solar EGUs.
•Refer to “Results of Operations” for discussion of expected issuances of common stock dividends and expected future issuances and retirements of long-term debt by the end of 2022.
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):

| 2021 |  | 2020
| Income (Loss) |  | EPS |  | Income |  | EPS
Utilities and Corporate Services | $254 |  | $1.01 |  | $224 |  | $0.89
ATC Holdings | 8 |  | 0.03 |  | 8 |  | 0.03
Non-utility and Parent | (6) |  | (0.02) |  | 14 |  | 0.06
Alliant Energy Consolidated | $256 |  | $1.02 |  | $246 |  | $0.98

Alliant Energy’s Utilities and Corporate Services net income increased by $30 million for the three-month period, primarily due to higher earnings resulting from IPL’s and WPL’s increasing rate base, as well as higher sales due in part to the derecho windstorm in Iowa and COVID-19 sales impacts in the third quarter of 2020. These items were partially offset by higher depreciation expense and lower AFUDC.
Alliant Energy’s Non-utility and Parent net income decreased by $20 million for the three-month period, primarily due to an adjustment in 2020 to the credit loss liability related to legacy guarantees associated with an affiliate of Whiting Petroleum and timing of income taxes.

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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 | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Operating income | $289 |  | $272 |  | $180 |  | $162 |  | $100 |  | $89
Electric utility revenues | $939 |  | $852 |  | $555 |  | $519 |  | $384 |  | $333
Electric production fuel and purchased power expenses | (207) |  | (179) |  | (101) |  | (102) |  | (105) |  | (78)
Electric transmission service expense | (148) |  | (132) |  | (103) |  | (93) |  | (44) |  | (39)
Utility Electric Margin (non-GAAP) | 584 |  | 541 |  | 351 |  | 324 |  | 235 |  | 216
Gas utility revenues | 50 |  | 42 |  | 31 |  | 24 |  | 19 |  | 18
Cost of gas sold | (18) |  | (11) |  | (12) |  | (6) |  | (6) |  | (4)
Utility Gas Margin (non-GAAP) | 32 |  | 31 |  | 19 |  | 18 |  | 13 |  | 14
Other utility revenues | 13 |  | 10 |  | 13 |  | 10 |  | — |  | —
Non-utility revenues | 22 |  | 16 |  | — |  | — |  | — |  | —
Other operation and maintenance expenses | (171) |  | (143) |  | (95) |  | (85) |  | (66) |  | (65)
Depreciation and amortization expenses | (165) |  | (156) |  | (94) |  | (89) |  | (70) |  | (65)
Taxes other than income tax expense | (26) |  | (27) |  | (14) |  | (16) |  | (12) |  | (11)
Operating income | $289 |  | $272 |  | $180 |  | $162 |  | $100 |  | $89

| Alliant Energy |  | IPL |  | WPL
Nine Months | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Operating income | $663 |  | $628 |  | $394 |  | $347 |  | $245 |  | $255
Electric utility revenues | $2,357 |  | $2,257 |  | $1,343 |  | $1,332 |  | $1,014 |  | $925
Electric production fuel and purchased power expenses | (478) |  | (527) |  | (215) |  | (304) |  | (263) |  | (223)
Electric transmission service expense | (403) |  | (326) |  | (274) |  | (212) |  | (128) |  | (114)
Utility Electric Margin (non-GAAP) | 1,476 |  | 1,404 |  | 854 |  | 816 |  | 623 |  | 588
Gas utility revenues | 289 |  | 253 |  | 165 |  | 141 |  | 124 |  | 112
Cost of gas sold | (149) |  | (117) |  | (84) |  | (63) |  | (65) |  | (53)
Utility Gas Margin (non-GAAP) | 140 |  | 136 |  | 81 |  | 78 |  | 59 |  | 59
Other utility revenues | 36 |  | 32 |  | 35 |  | 31 |  | 1 |  | 1
Non-utility revenues | 60 |  | 57 |  | — |  | — |  | — |  | —
Other operation and maintenance expenses | (477) |  | (465) |  | (253) |  | (269) |  | (194) |  | (172)
Depreciation and amortization expenses | (494) |  | (454) |  | (281) |  | (264) |  | (209) |  | (186)
Taxes other than income tax expense | (78) |  | (82) |  | (42) |  | (45) |  | (35) |  | (35)
Operating income | $663 |  | $628 |  | $394 |  | $347 |  | $245 |  | $255

Operating Income Variances - Variances between periods in operating income for the three and nine months ended September 30, 2021 compared to the same periods in 2020 were as follows (in millions):

| Three Months |  | Nine Months
| Alliant Energy |  | IPL |  | WPL |  | Alliant Energy |  | IPL |  | WPL
Total higher utility electric margin variance (Refer to details below) | $43 |  | $27 |  | $19 |  | $72 |  | $38 |  | $35
Total higher (lower) utility gas margin variance (Refer to details below) | 1 |  | 1 |  | (1) |  | 4 |  | 3 |  | —
Total (higher) lower other operation and maintenance expenses variance (Refer to details below) | (28) |  | (10) |  | (1) |  | (12) |  | 16 |  | (22)
Higher depreciation and amortization expense primarily due to additional plant in service in 2020 and 2021, including IPL’s new wind generation, and WPL’s West Riverside Energy Center and Kossuth wind farm | (9) |  | (5) |  | (5) |  | (40) |  | (17) |  | (23)
Other | 10 |  | 5 |  | (1) |  | 11 |  | 7 |  | —
| $17 |  | $18 |  | $11 |  | $35 |  | $47 |  | ($10)

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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
| 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Three Months |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Retail | $845 |  | $779 |  | 7,031 |  | 6,762 |  | $40 |  | $34 |  | 3,264 |  | 3,500
Sales for resale | 78 |  | 54 |  | 1,853 |  | 1,453 |  | N/A |  | N/A |  | N/A |  | N/A
Transportation/Other | 16 |  | 19 |  | 18 |  | 17 |  | 10 |  | 8 |  | 26,365 |  | 24,842
| $939 |  | $852 |  | 8,902 |  | 8,232 |  | $50 |  | $42 |  | 29,629 |  | 28,342
Nine Months |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Retail | $2,124 |  | $2,049 |  | 19,262 |  | 18,496 |  | $258 |  | $224 |  | 33,299 |  | 32,545
Sales for resale | 181 |  | 162 |  | 4,411 |  | 4,962 |  | N/A |  | N/A |  | N/A |  | N/A
Transportation/Other | 52 |  | 46 |  | 53 |  | 53 |  | 31 |  | 29 |  | 74,111 |  | 79,546
| $2,357 |  | $2,257 |  | 23,726 |  | 23,511 |  | $289 |  | $253 |  | 107,410 |  | 112,091

IPL | Electric |  | Gas
| Revenues |  | MWhs Sold |  | Revenues |  | Dths Sold
| 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Three Months |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Retail | $525 |  | $480 |  | 3,914 |  | 3,743 |  | $25 |  | $19 |  | 1,702 |  | 1,873
Sales for resale | 21 |  | 25 |  | 487 |  | 765 |  | N/A |  | N/A |  | N/A |  | N/A
Transportation/Other | 9 |  | 14 |  | 9 |  | 9 |  | 6 |  | 5 |  | 9,308 |  | 9,020
| $555 |  | $519 |  | 4,410 |  | 4,517 |  | $31 |  | $24 |  | 11,010 |  | 10,893
Nine Months |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Retail | $1,259 |  | $1,227 |  | 10,810 |  | 10,414 |  | $145 |  | $122 |  | 17,268 |  | 16,950
Sales for resale | 49 |  | 75 |  | 1,160 |  | 3,090 |  | N/A |  | N/A |  | N/A |  | N/A
Transportation/Other | 35 |  | 30 |  | 26 |  | 27 |  | 20 |  | 19 |  | 29,727 |  | 29,127
| $1,343 |  | $1,332 |  | 11,996 |  | 13,531 |  | $165 |  | $141 |  | 46,995 |  | 46,077

WPL | Electric |  | Gas
| Revenues |  | MWhs Sold |  | Revenues |  | Dths Sold
| 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Three Months |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Retail | $320 |  | $299 |  | 3,117 |  | 3,019 |  | $15 |  | $15 |  | 1,562 |  | 1,627
Sales for resale | 57 |  | 29 |  | 1,366 |  | 688 |  | N/A |  | N/A |  | N/A |  | N/A
Transportation/Other | 7 |  | 5 |  | 9 |  | 8 |  | 4 |  | 3 |  | 17,057 |  | 15,822
| $384 |  | $333 |  | 4,492 |  | 3,715 |  | $19 |  | $18 |  | 18,619 |  | 17,449
Nine Months |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Retail | $865 |  | $822 |  | 8,452 |  | 8,082 |  | $113 |  | $102 |  | 16,031 |  | 15,595
Sales for resale | 132 |  | 87 |  | 3,251 |  | 1,872 |  | N/A |  | N/A |  | N/A |  | N/A
Transportation/Other | 17 |  | 16 |  | 27 |  | 26 |  | 11 |  | 10 |  | 44,384 |  | 50,419
| $1,014 |  | $925 |  | 11,730 |  | 9,980 |  | $124 |  | $112 |  | 60,415 |  | 66,014

Sales Trends and Temperatures - Alliant Energy’s retail electric and gas sales volumes increased 4% and decreased 7%, respectively, for the three months ended September 30, 2021 compared to the same period in 2020, primarily due to COVID-19 impacts in Alliant Energy’s service territories, impacts from the derecho windstorm in IPL’s service territory in August 2020 and changes in temperatures. Alliant Energy’s retail electric and gas sales volumes increased 4% and 2%, respectively, for the nine months ended September 30, 2021 compared to the same period in 2020, primarily due to changes in temperatures, COVID-19 impacts in Alliant Energy’s service territories and impacts from the derecho windstorm in IPL’s service territory in August 2020, partially offset by the impact on sales of the additional day due to leap year in 2020. For the three and nine months ended September 30, 2021, changes in COVID-19 impacts resulted in decreases for retail electric residential sales volumes and increases for retail electric commercial and industrial sales.

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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
| 2021 |  | 2020 |  | Change |  | 2021 |  | 2020 |  | Change |  | 2021 |  | 2020 |  | Change |  | 2021 |  | 2020 |  | Change
IPL | $5 |  | $3 |  | $2 |  | $16 |  | $2 |  | $14 |  | ($1) |  | $— |  | ($1) |  | $1 |  |  | $— |  |  | $1 |
WPL | — |  | 3 |  | (3) |  | 9 |  | 3 |  | 6 |  | — |  | — |  | — |  | — |  |  | (1) |  |  | 1 |
Total Alliant Energy | $5 |  | $6 |  | ($1) |  | $25 |  | $5 |  | $20 |  | ($1) |  | $— |  | ($1) |  | $1 |  |  | ($1) |  |  | $2 |

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 utility electric margins for the three and nine months ended September 30, 2021 compared to the same periods in 2020 as follows (in millions):

| Three Months |  | Nine Months
| Alliant Energy |  | IPL |  | WPL |  | Alliant Energy |  | IPL |  | WPL
Higher revenue requirements due to increasing rate base (a) (b) | $12 |  | $9 |  | $3 |  | $38 |  | $28 |  | $10
Estimated changes in sales volumes caused by temperatures | (1) |  | 2 |  | (3) |  | 20 |  | 14 |  | 6
Higher wholesale margins at WPL partially due to a new wholesale customer in 2021 | 2 |  | — |  | 2 |  | 4 |  | — |  | 4
Lower revenues at IPL related to changes in recovery amounts for energy efficiency costs through the energy efficiency rider (mostly offset by changes in energy efficiency expense) | (3) |  | (3) |  | — |  | (11) |  | (11) |  | —
Higher (lower) revenues at IPL due to changes in credits on customers’ bills related to excess deferred income tax benefits amortization through the tax benefit rider (offset by changes in income tax) | 8 |  | 8 |  | — |  | (4) |  | (4) |  | —
(Higher) lower WPL electric fuel-related costs, net of recoveries | 5 |  | — |  | 5 |  | (2) |  | — |  | (2)
Other (includes higher temperature-normalized sales primarily due to derecho windstorm in 2020 and COVID-19 impacts) | 20 |  | 11 |  | 12 |  | 27 |  | 11 |  | 17
| $43 |  | $27 |  | $19 |  | $72 |  | $38 |  | $35

(a)IPL’s final retail electric base rate increase was effective February 26, 2020. Effective with final rates, the recovery of, and return on, IPL’s new wind generation placed in service in 2019 and 2020 is provided through the renewable energy rider. The final rate increase includes a reduction for anticipated production tax credits for IPL’s new wind generation. This reduction is expected to be offset by a reduction in income tax expense resulting from production tax credits recognized from this new wind generation. In September 2020, IPL made a buyout payment of $110 million in exchange for shortening the terms of its DAEC PPA by 5 years. The higher revenue requirements from the buyout payment, including a return on such costs, is being recovered from IPL’s retail customers from 2021 through the end of 2025.
(b)In December 2020, the PSCW issued an order authorizing WPL to maintain its current retail electric base rates through the end of 2021. WPL will utilize anticipated fuel-related cost savings and excess deferred income tax benefits in 2021 to offset the revenue requirement impacts of increasing electric rate base, including the Kossuth wind farm, which was placed in service in October 2020. The lower fuel expense benefits are recognized in electric margin and the additional amount of excess deferred income tax benefits is recognized as a reduction in income tax expense.
Utility Gas Margin Variances - The following items contributed to increased (decreased) utility gas margins for the three and nine months ended September 30, 2021 compared to the same periods in 2020 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) |  | $— |  | $2 |  | $1 |  | $1
Other | 2 |  | 2 |  | (1) |  | 2 |  | 2 |  | (1)
| $1 |  | $1 |  | ($1) |  | $4 |  | $3 |  | $—

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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, 2021 compared to the same periods in 2020 as follows (in millions):

| Three Months |  | Nine Months
| Alliant Energy |  | IPL |  | WPL |  | Alliant Energy |  | IPL |  | WPL
Higher generation operation and maintenance expenses | ($10) |  | ($8) |  | ($2) |  | ($21) |  | ($12) |  | ($9)
Credit loss adjustments in 2020 related to guarantees for an affiliate of Whiting Petroleum | (15) |  | — |  | — |  | (7) |  | — |  | —
Lower energy efficiency expense at IPL (primarily offset by lower revenues) | 2 |  | 2 |  | — |  | 10 |  | 10 |  | —
(Higher) lower bad debt expense at IPL | (2) |  | (2) |  | — |  | 8 |  | 8 |  | —
Other | (3) |  | (2) |  | 1 |  | (2) |  | 10 |  | (13)
| ($28) |  | ($10) |  | ($1) |  | ($12) |  | $16 |  | ($22)

Other Income and Deductions Variances - The following items contributed to increased other income and deductions for the three and nine months ended September 30, 2021 compared to the same periods in 2020 as follows (in millions):

| Three Months |  | Nine Months
| Alliant Energy |  | IPL |  | WPL |  | Alliant Energy |  | IPL |  | WPL
Lower interest expense | $— |  | $1 |  | $1 |  | $1 |  | $1 |  | $1
Lower AFUDC primarily due to changes in construction work in progress balances related to IPL’s new wind generation, and WPL’s West Riverside Energy Center and Kossuth wind farm placed in service in 2020 | (6) |  | (4) |  | (1) |  | (35) |  | (14) |  | (20)
Other | (2) |  | 1 |  | (1) |  | 1 |  | 1 |  | —
| ($8) |  | ($2) |  | ($1) |  | ($33) |  | ($12) |  | ($19)

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 - In the fourth quarter of 2021, IPL currently expects to issue up to $300 million of long-term debt and redeem all of its cumulative preferred stock at par value for approximately $200 million plus accrued and unpaid dividends up to the redemption date. WPL and AEF currently expect to issue up to $300 million and $800 million of long-term debt, respectively, in 2022. WPL, AEF and Corporate Services have $250 million, $300 million and $75 million of long-term debt maturing in 2022, respectively. Alliant Energy currently expects to issue approximately $25 million of common stock in 2022 through its Shareowner Direct Plan.
•Common Stock Dividends - Alliant Energy announced a 6% increase in its targeted 2022 annual common stock dividend to $1.71 per share, which is equivalent to a quarterly rate of $0.4275 per share, beginning with the February 2022 dividend payment. The timing and amount of future dividends is subject to an approved dividend declaration from Alliant Energy’s Board of Directors, and is dependent upon earnings expectations, capital requirements, and general financial business conditions, among other factors.
•Higher Earnings on Increasing Rate Base - Alliant Energy and WPL currently expect an increase in earnings in 2022 compared to 2021 due to impacts from increasing revenue requirements related to investments in the utility business, including WPL’s solar investments. WPL’s increased revenue requirements are expected to be offset by higher income tax expense as a result of lower tax benefits.
•Other Operation and Maintenance Expenses - Alliant Energy, IPL and WPL currently expect a decrease in other operation and maintenance expenses in 2022 compared to 2021 due to cost reductions resulting from operating efficiencies.
•Depreciation and Amortization Expenses - Alliant Energy, IPL and WPL currently expect an increase in depreciation and amortization expenses in 2022 compared to 2021 due to property additions, including WPL’s expansion of solar generation.
•Interest Expense - Alliant Energy, IPL and WPL currently expect an increase in interest expense in 2022 compared to 2021 due to financings completed in 2021 and planned in 2021 and 2022 as discussed above.
•Allowance for Funds Used During Construction - Alliant Energy and WPL currently expect AFUDC to increase in 2022 compared to 2021 primarily due to increased construction work in progress balances related to WPL’s solar generation.

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CUSTOMER INVESTMENTS
Renewable Generation
Alliant Energy’s cleaner energy strategy, or Clean Energy Blueprints, currently includes the planned development and acquisition of additional renewable energy, including approximately 1,100 MW of solar generation at WPL with in-service dates in 2022-2024, approximately 400 MW of solar generation at IPL with in-service dates in 2023-2024 and approximately 75 MW of battery storage in 2024 at IPL. Alliant Energy, IPL and WPL continue to evaluate additional opportunities to add more renewable generation, including wind repowering, and additional solar generation and distributed energy resources, including community solar and energy storage systems. Estimated capital expenditures for these projects for 2021 through 2025 are included in the “Renewable projects” line in the construction and acquisition table in “Liquidity and Capital Resources.” These estimates include current expectations for higher costs for various projects, as supply constraints and commodity inflation continue to be prevalent in the solar market. In addition, these estimates reflect later expected in-service dates for certain solar projects to reflect the tight market for solar panels. IPL and WPL currently assume that a portion of the construction costs for the new solar generation will be financed by a tax equity partner, which is discussed in “IPL and WPL Solar Project Tax Equity Credits” in “Liquidity and Capital Resources.”
WPL’s Solar Generation and Distributed Energy Resources - In June 2021, WPL received an order from the PSCW for its first Certificate of Authority authorizing WPL to acquire, own and operate 675 MW of new solar generation in the following Wisconsin counties: Grant (200 MW), Sheboygan (150 MW), Wood (150 MW), Jefferson (75 MW), Richland (50 MW) and Rock (50 MW). In July 2021, WPL notified the PSCW that it currently expects estimated construction costs and related rate base additions associated with its 675 MW of new solar generation will exceed amounts approved by the PSCW in June 2021 by approximately 7-10%. In September 2021, WPL filed revised estimated construction costs and related rate base additions for its second Certificate of Authority with the PSCW for approval to acquire, construct, own, and operate up to 414 MW of new solar generation in the following Wisconsin counties: Dodge (150 MW), Waushara (99 MW), Rock (65 MW), Grant (50 MW) and Green (50 MW). These projects are expected to be placed in-service in 2022-2024. The 1,089 MW of new solar generation would replace energy and capacity being eliminated with the planned retirement of the coal-fired Edgewater Generating Station (414 MW) by the end of 2022, and Columbia Unit 1 by the end of 2023 and Columbia Unit 2 by the end of 2024 (595 MW in aggregate), which are the last coal-fired EGUs at WPL. The retirement of these coal-fired EGUs supports Alliant Energy’s strategy, which is focused on meeting its customers’ energy needs in an economical, efficient and sustainable manner. As a result of WPL’s neighboring utilities anticipated exercise of their options to purchase a partial ownership interest in West Riverside, WPL anticipates additional capacity needs by 2024, which may include additional solar generation and distributed energy resources such as community solar and energy storage systems.
IPL’s Solar Generation and Distributed Energy Resources - In November 2021, IPL filed for advance rate-making principles with the IUB for up to 400 MW of solar generation with in-service dates in 2023 and 2024 and approximately 75 MW of battery storage in 2024. The advance rate-making principles filing included requests for a fixed cost cap of $1,575/kilowatt, including AFUDC and transmission upgrade costs among other costs, and a return on common equity of 11.40%, and proposes that a portion of the construction be financed by tax equity partners. In addition, the filing included a request that any costs incurred in excess of the cost cap be incorporated into rates if determined to be reasonable and prudent. The 400 MW of new solar generation and 75 MW of battery storage would help replace a portion of the energy and capacity expected to be eliminated with the planned retirement of the coal-fired Lansing Generating Station (275 MW) by the end of 2022 and the expected reduction of energy and capacity resulting from the planned fuel switch of the Burlington Generating Station (212 MW) from coal to natural gas by the end of 2021. In addition, IPL’s plans include additional distributed energy resources, including community solar and energy storage systems, to add energy and capacity.
LIQUIDITY AND CAPITAL RESOURCES
The liquidity and capital resources summary included in the 2020 Form 10-K has not changed materially, except as described below.
Liquidity Position - At September 30, 2021, Alliant Energy had $20 million of cash and cash equivalents, $684 million ($187 million at the parent company, $100 million at IPL and $397 million at WPL) of available capacity under the single revolving credit facility and $60 million of available capacity at IPL under its sales of accounts receivable program.

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Capital Structure - Capital structures at September 30, 2021 were as follows (Long-term Debt (including current maturities) (LD); Short-term Debt (SD); Common Equity (CE); IPL’s Preferred Stock (PS)):
Cash Flows - Selected information from the cash flows statements was as follows (in millions):

| Alliant Energy |  | IPL |  | WPL
| 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Cash, cash equivalents and restricted cash, January 1 | $56 |  | $18 |  | $50 |  | $9 |  | $3 |  | $4
Cash flows from (used for): |  |  |  |  |  |  |  |  |  |  |
Operating activities | 477 |  | 436 |  | 95 |  | 19 |  | 349 |  | 402
Investing activities | (452) |  | (679) |  | 122 |  | (202) |  | (510) |  | (465)
Financing activities | (57) |  | 419 |  | (254) |  | 359 |  | 162 |  | 61
Net increase (decrease) | (32) |  | 176 |  | (37) |  | 176 |  | 1 |  | (2)
Cash, cash equivalents and restricted cash, September 30 | $24 |  | $194 |  | $13 |  | $185 |  | $4 |  | $2

Operating Activities - The following items contributed to increased (decreased) operating activity cash flows for the nine months ended September 30, 2021 compared to the same period in 2020 (in millions):

| Alliant Energy |  | IPL |  | WPL
DAEC PPA amendment buyout payment in 2020 | $110 |  | $110 |  | $—
Credits issued to IPL’s retail electric customers in 2020 through its transmission cost rider for amounts previously collected in rates | 42 |  | 42 |  | —
Increased collections from IPL’s and WPL’s retail customers caused by temperature impacts on electric and gas sales | 22 |  | 15 |  | 7
Changes in the sales of accounts receivable at IPL | (68) |  | (68) |  | —
Refunds received in 2020 related to the MISO transmission owner return on equity complaint FERC orders | (20) |  | (15) |  | (5)
Higher natural gas cost payments primarily from extreme temperatures in February 2021 resulting in under-recovered natural gas costs at IPL (Refer to Note 2) | (15) |  | (15) |  | —
Credits issued to IPL’s retail electric customers in 2021 through its transmission cost rider for refunds received in 2020 for the MISO transmission owner return on equity complaints | (14) |  | (14) |  | —
Changes in income taxes paid/refunded | (7) |  | 40 |  | (29)
Other (primarily due to other changes in working capital) | (9) |  | (19) |  | (26)
| $41 |  | $76 |  | ($53)

Investing Activities - The following items contributed to increased (decreased) investing activity cash flows for the nine months ended September 30, 2021 compared to the same period in 2020 (in millions):

| Alliant Energy |  | IPL |  | WPL
(Higher) lower utility construction and acquisition expenditures (a) | $163 |  | $180 |  | ($17)
Changes in the amount of cash receipts on sold receivables | 105 |  | 105 |  | —
Refund from ATC in 2020 for construction deposits WPL previously provided to ATC for transmission network upgrades for West Riverside | (42) |  | — |  | (42)
Other | 1 |  | 39 |  | 14
| $227 |  | $324 |  | ($45)

(a)Largely due to lower expenditures for IPL’s and WPL’s expansion of wind generation, IPL’s and WPL’s electric and gas distribution systems and WPL’s West Riverside Energy Center, partially offset by higher expenditures for 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 reliability of the electric and gas distribution systems. Construction and acquisition expenditures for 2021 through 2025 are currently anticipated as follows (in millions), and are focused on the transition to cleaner energy and strengthening the resiliency of Alliant Energy’s, IPL’s and WPL’s electric grid. Cost estimates represent Alliant Energy’s, IPL’s and WPL’s portion of construction expenditures and exclude AFUDC and capitalized interest, if applicable. Such estimates do not reflect the assumption that a portion of the construction is expected to be financed by tax equity partners, as discussed below in “IPL and WPL Solar Project Tax Equity Credits.” Refer to "Custo me r Investments" for further discussion of certain key projects impacting construction and acquisition plans related to the utility business.

| Alliant Energy |  | IPL |  | WPL
| 2021 | 2022 | 2023 | 2024 | 2025 |  | 2021 | 2022 | 2023 | 2024 | 2025 |  | 2021 | 2022 | 2023 | 2024 | 2025
Generation: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Renewable projects | $385 |  | $550 |  | $520 |  | $1,270 |  | $675 |  |  | $20 |  | $80 |  | $200 |  | $510 |  | $340 |  |  | $365 |  | $470 |  | $320 |  | $760 |  | $335 |
Other | 90 |  | 105 |  | 185 |  | 190 |  | 90 |  |  | 55 |  | 65 |  | 150 |  | 140 |  | 45 |  |  | 35 |  | 40 |  | 35 |  | 50 |  | 45 |
Distribution: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Electric systems | 490 |  | 445 |  | 560 |  | 605 |  | 625 |  |  | 265 |  | 210 |  | 300 |  | 340 |  | 350 |  |  | 225 |  | 235 |  | 260 |  | 265 |  | 275 |
Gas systems | 70 |  | 70 |  | 80 |  | 70 |  | 75 |  |  | 35 |  | 35 |  | 40 |  | 35 |  | 35 |  |  | 35 |  | 35 |  | 40 |  | 35 |  | 40 |
Other | 165 |  | 185 |  | 185 |  | 185 |  | 205 |  |  | 25 |  | 30 |  | 30 |  | 35 |  | 40 |  |  | 20 |  | 25 |  | 25 |  | 35 |  | 30 |
| $1,200 |  | $1,355 |  | $1,530 |  | $2,320 |  | $1,670 |  |  | $400 |  | $420 |  | $720 |  | $1,060 |  | $810 |  |  | $680 |  | $805 |  | $680 |  | $1,145 |  | $725 |

Financing Activities - The following items contributed to increased (decreased) financing activity cash flows for the nine months ended September 30, 2021 compared to the same period in 2020 (in millions):

| Alliant Energy |  | IPL |  | WPL
Lower net proceeds from issuance of long-term debt | ($750) |  | ($400) |  | ($50)
Lower net proceeds from common stock issuances | (219) |  | — |  | —
Net changes in the amount of commercial paper outstanding | (158) |  | — |  | (225)
(Higher) lower common stock dividends | (23) |  | (124) |  | 1
Lower payments to retire long-term debt | 650 |  | 200 |  | 150
Higher (lower) capital contributions from IPL’s and WPL’s parent company, Alliant Energy | — |  | (295) |  | 220
Other | 24 |  | 6 |  | 5
| ($476) |  | ($613) |  | $101

IPL and WPL Solar Project Tax Equity Credits - IPL and WPL each propose to own and operate their planned solar projects discussed in “Customer Investments,” which are currently expected to qualify for 26% to 30% investment tax credits, through a tax equity partnership, with approximately 25% to 45% of the construction costs financed with capital from the tax equity partner. Assuming a portion of the construction costs are financed by the tax equity partner, IPL would receive approximately $25 million in 2023 and $260 million in 2024 from the tax equity partner, and WPL would receive approximately $190 million in 2022, $100 million in 2023, $320 million in 2024 and $170 million in 2025 from the tax equity partner. IPL and WPL would expect to include their portion of capital expenditures, less the amounts financed by the tax equity partner, in their respective rate base.
Common Stock Issuances and Common Stock Dividends - Refer to Note 5 for discussion of common stock issuances by Alliant Energy in 2021. Refer to “Results of Operations” for discussion of expected common stock dividends in 2022.
Short- and Long-term Debt - Refer to Note 7(a) for discussion of changes to Alliant Energy's, IPL's and WPL's credit facility capacity amounts in the third quarter of 2021. Refer to Note 7(b) for discussion of WPL’s issuance of long-term debt in 2021. Refer to “Results of Oper ation s” for discussion of expected future issuances and retirements of long-term debt by the end of 2022.
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 2020 Form 10-K and has not changed materially from the items reported in the 2020 Form 10-K, except for the items described in Notes 3, 7 and 1 4.

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OTHER MATTERS
Critical Accounting Policies and Estimates - The summary of critical accounting policies and estimates included in the 2020 Form 10-K has not changed materially, except as described below.
Long-Lived Assets -
Regulated Operations -
Generating Units Subject to Early Retirement - Refer to Note 1(b) for discussion of the anticipated retirement of Columbia Unit 1 by the end of 2023 and Columbia Unit 2 by the end of 2024, and Alliant Energy’s and WPL’s conclusion that these EGUs met the criteria to be considered probable of abandonment and no disallowance was required as of September 30, 2021.
ITEM 3. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK
Quantitative and Qualitative Disclosures About Market Risk are reported in the 2020 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 of September 30, 2021 pursuant to the requirements of the Securities Exchange Act of 1934, as amended. Based on their evaluation, the Chief Executive Officer and the Chief Financial Officer concluded that Alliant Energy’s, IPL’s and WPL’s disclosure controls and procedures were effective as of the quarter ended September 30, 2021.
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, 2021 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 2020 Form 10-K have not changed materially.
ITEM 2. UNREGISTERED SALES OF EQUITY SECURITIES AND USE OF PROCEEDS
A summary of Alliant Energy common stock repurchases for the quarter ended September 30, 2021 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 |  | 3,753 |  | $56.78 |  | — |  | N/A
August 1 through August 31 |  | 2,526 |  | 61.64 |  | — |  | N/A
September 1 through September 30 |  | 72 |  | 59.59 |  | — |  | N/A
|  | 6,351 |  | 58.74 |  | — |  |

(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.

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

Exhibit Number | Description
3.1 | Amended and Restated Bylaws of Alliant Energy, effective September 23, 2021 (incorporated by refere nce to Exhibit 3.1 to All iant Energy’s Form 8-K, filed September 24, 2021 (File No. 1-9894))
4.1 | First Supplemental Indenture, dated September 16, 2021, among WPL, Wells Fargo Bank, National Association, as Original Trustee, and U.S. Bank National Association, as Series Trustee (incorporated by reference to Exhibit 4.1 to WPL's Form 8-K, filed September 16, 2021 (File No. 0-337))
10.1# | Form of Key Executive Employment and Severance Agreement (KEESA), by and between Alliant Energy and J.O. Larsen (incorporated by reference to Exhibit 10.1 to Alliant Energy’s Form 8-K, filed October 28, 2021 (File No. 1-9894))
10.2# | Form of KEESA, by and between Alliant Energy and each of J.H. Gallegos, R.J. Durian, D.A. de Leon and T.L. Kouba (incorporated by reference to Exhibit 10.2 to Alliant Energy’s Form 8-K, filed October 28, 2021 (File No. 1-9894))
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)

# A management contract or compensatory plan or arrangement.
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 5th day of November 2021.

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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