Item 1. CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (UNAUDITED)

ALLIANT ENERGY CORPORATION

CONDENSED CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED)

			For the Three Months
			Ended March 31,
			2023						2022
			(in millions, except per share amounts)
Revenues:
Electric utility			$768						$773
Gas utility			276						262
Other utility			11						11
Non-utility			22						22
Total revenues			1,077						1,068
Operating expenses:
Electric production fuel and purchased power			157						168
Electric transmission service			146						138
Cost of gas sold			181						168
Other operation and maintenance			174						153
Depreciation and amortization			166						166
Taxes other than income taxes			31						27
Total operating expenses			855						820
Operating income			222						248
Other (income) and deductions:
Interest expense			94						74
Equity income from unconsolidated investments, net			(17)						(15)
Allowance for funds used during construction			(19)						(11)
Other			3						—
Total other (income) and deductions			61						48
Income before income taxes			161						200
Income tax expense (benefit)			(2)						8
Net income attributable to Alliant Energy common shareowners			$163						$192
Weighted average number of common shares outstanding:
Basic			251.2						250.6
Diluted			251.4						250.9
Earnings per weighted average common share attributable to Alliant Energy common shareowners (basic and diluted)			$0.65						$0.77

Refer to accompanying Combined Notes to Condensed Consolidated Financial Statements.

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ALLIANT ENERGY CORPORATION

CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED)

			March 31, 2023						December 31, 2022
			(in millions, except per share and share amounts)
ASSETS
Current assets:
Cash and cash equivalents			$157						$20
Accounts receivable, less allowance for expected credit losses			428						516
Production fuel, at weighted average cost			60						53
Gas stored underground, at weighted average cost			64						132
Materials and supplies, at weighted average cost			158						140
Regulatory assets			193						166
Other			132						223
Total current assets			1,192						1,250
Property, plant and equipment, net			16,396						16,247
Investments:
ATC Holdings			363						358
Other			206						201
Total investments			569						559
Other assets:
Regulatory assets			1,887						1,880
Deferred charges and other			196						227
Total other assets			2,083						2,107
Total assets			$20,240						$20,163

LIABILITIES AND EQUITY
Current liabilities:
Current maturities of long-term debt			$808						$408
Commercial paper			60						642
Other short-term borrowings			50						—
Accounts payable			518						756
Regulatory liabilities			129						206
Other			343						351
Total current liabilities			1,908						2,363
Long-term debt, net (excluding current portion)			8,132						7,668
Other liabilities:
Deferred tax liabilities			1,957						1,943
Regulatory liabilities			1,102						1,118
Pension and other benefit obligations			273						277
Other			540						518
Total other liabilities			3,872						3,856
Commitments and contingencies (Note 13)
Equity:
Alliant Energy Corporation common equity:
Common stock - $0.01 par value - 480,000,000 shares authorized; 251,387,788 and 251,134,966 shares outstanding			3						3
Additional paid-in capital			2,780						2,777
Retained earnings			3,559						3,509
Accumulated other comprehensive loss			(1)						—
Shares in deferred compensation trust - 394,363 and 402,134 shares at a weighted average cost of $33.12 and $32.63 per share			(13)						(13)
Total Alliant Energy Corporation common equity			6,328						6,276
Total liabilities and equity			$20,240						$20,163

Refer to accompanying Combined Notes to Condensed Consolidated Financial Statements.

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ALLIANT ENERGY CORPORATION

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED)

			For the Three Months
			Ended March 31,
			2023						2022
			(in millions)
Cash flows from operating activities:
Net income			$163						$192
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation and amortization			166						166
Other			(6)						12
Other changes in assets and liabilities:
Accounts receivable			(86)						(161)
Gas stored underground			68						55
Derivative assets			115						(85)
Regulatory assets			(32)						19
Accounts payable			(97)						(37)
Regulatory liabilities			(95)						92
Other			(8)						(2)
Net cash flows from operating activities			188						251
Cash flows used for investing activities:
Construction and acquisition expenditures:
Utility business			(417)						(307)
Other			(34)						(23)
Cash receipts on sold receivables			173						115
Proceeds from sale of partial ownership interest in West Riverside			25						—
Other			(10)						(8)
Net cash flows used for investing activities			(263)						(223)
Cash flows from financing activities:
Common stock dividends			(113)						(107)
Proceeds from issuance of long-term debt			862						650
Payments to retire long-term debt			—						(300)
Net change in commercial paper and other short-term borrowings			(532)						(239)
Other			(5)						(1)
Net cash flows from financing activities			212						3
Net increase in cash, cash equivalents and restricted cash			137						31
Cash, cash equivalents and restricted cash at beginning of period			24						40
Cash, cash equivalents and restricted cash at end of period			$161						$71
Supplemental cash flows information:
Cash paid during the period for:
Interest			($93)						($62)
Significant non-cash investing and financing activities:
Accrued capital expenditures			$254						$134
Beneficial interest obtained in exchange for securitized accounts receivable			$153						$227

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
			Ended March 31,
			2023						2022
			(in millions)
Revenues:
Electric utility			$388						$400
Gas utility			150						139
Steam and other			11						11
Total revenues			549						550
Operating expenses:
Electric production fuel and purchased power			47						67
Electric transmission service			104						97
Cost of gas sold			95						85
Other operation and maintenance			95						83
Depreciation and amortization			96						94
Taxes other than income taxes			16						14
Total operating expenses			453						440
Operating income			96						110
Other (income) and deductions:
Interest expense			37						37
Allowance for funds used during construction			(3)						(3)
Other			1						—
Total other (income) and deductions			35						34
Income before income taxes			61						76
Income tax benefit			(11)						(11)
Net income			$72						$87

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)

			March 31, 2023						December 31, 2022
			(in millions, except per share and share amounts)
ASSETS
Current assets:
Cash and cash equivalents			$35						$15
Accounts receivable, less allowance for expected credit losses			191						259
Production fuel, at weighted average cost			26						23
Gas stored underground, at weighted average cost			26						60
Materials and supplies, at weighted average cost			92						83
Regulatory assets			75						85
Other			49						93
Total current assets			494						618
Property, plant and equipment, net			8,112						8,046
Other assets:
Regulatory assets			1,308						1,301
Deferred charges and other			93						110
Total other assets			1,401						1,411
Total assets			$10,007						$10,075

LIABILITIES AND EQUITY
Current liabilities:
Accounts payable			$222						$239
Accounts payable to associated companies			37						28
Accrued taxes			59						52
Accrued interest			35						35
Regulatory liabilities			73						114
Other			92						113
Total current liabilities			518						581
Long-term debt, net			3,647						3,646
Other liabilities:
Deferred tax liabilities			1,053						1,047
Regulatory liabilities			624						640
Pension and other benefit obligations			61						62
Other			294						291
Total other liabilities			2,032						2,040
Commitments and contingencies (Note 13)
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			2,807						2,807
Retained earnings			970						968
Total Interstate Power and Light Company common equity			3,810						3,808
Total liabilities and equity			$10,007						$10,075

Refer to accompanying Combined Notes to Condensed Consolidated Financial Statements.

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INTERSTATE POWER AND LIGHT COMPANY

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED)

			For the Three Months
			Ended March 31,
			2023						2022
			(in millions)
Cash flows from operating activities:
Net income			$72						$87
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation and amortization			96						94
Deferred tax expense and tax credits			3						15
Other			(2)						(2)
Other changes in assets and liabilities:
Accounts receivable			(106)						(128)
Income tax refunds receivable			(7)						(17)
Gas stored underground			34						29
Derivative assets			69						(43)
Accounts payable			(56)						(8)
Regulatory liabilities			(59)						59
Other			(20)						3
Net cash flows from operating activities			24						89
Cash flows from investing activities:
Construction and acquisition expenditures			(101)						(96)
Cash receipts on sold receivables			173						115
Other			(2)						(1)
Net cash flows from investing activities			70						18
Cash flows used for financing activities:
Common stock dividends			(70)						(81)
Other			(4)						2
Net cash flows used for financing activities			(74)						(79)
Net increase in cash, cash equivalents and restricted cash			20						28
Cash, cash equivalents and restricted cash at beginning of period			15						34
Cash, cash equivalents and restricted cash at end of period			$35						$62
Supplemental cash flows information:
Cash paid during the period for:
Interest			($37)						($37)
Significant non-cash investing and financing activities:
Accrued capital expenditures			$98						$27
Beneficial interest obtained in exchange for securitized accounts receivable			$153						$227

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
			Ended March 31,
			2023						2022
			(in millions)
Revenues:
Electric utility			$380						$373
Gas utility			126						123
Total revenues			506						496
Operating expenses:
Electric production fuel and purchased power			109						101
Electric transmission service			42						41
Cost of gas sold			86						83
Other operation and maintenance			66						58
Depreciation and amortization			68						70
Taxes other than income taxes			14						12
Total operating expenses			385						365
Operating income			121						131
Other (income) and deductions:
Interest expense			36						27
Allowance for funds used during construction			(16)						(9)
Other			1						—
Total other (income) and deductions			21						18
Income before income taxes			100						113
Income tax expense			12						21
Net income			$88						$92

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)

			March 31, 2023						December 31, 2022
			(in millions, except per share and share amounts)
ASSETS
Current assets:
Cash and cash equivalents			$86						$5
Accounts receivable, less allowance for expected credit losses			225						244
Production fuel, at weighted average cost			34						29
Gas stored underground, at weighted average cost			38						73
Materials and supplies, at weighted average cost			63						54
Regulatory assets			118						81
Prepaid gross receipts tax			31						42
Other			26						60
Total current assets			621						588
Property, plant and equipment, net			7,792						7,722
Other assets:
Regulatory assets			579						579
Deferred charges and other			82						98
Total other assets			661						677
Total assets			$9,074						$8,987

LIABILITIES AND EQUITY
Current liabilities:
Commercial paper			$60						$290
Accounts payable			233						456
Regulatory liabilities			56						92
Other			163						111
Total current liabilities			512						949
Long-term debt, net			3,067						2,770
Other liabilities:
Deferred tax liabilities			787						789
Regulatory liabilities			478						478
Pension and other benefit obligations			139						140
Other			378						370
Total other liabilities			1,782						1,777
Commitments and contingencies (Note 13)
Equity:
Wisconsin Power and Light Company common equity:
Common stock - $5 par value - 18,000,000 shares authorized; 13,236,601 shares outstanding			66						66
Additional paid-in capital			2,413						2,233
Retained earnings			1,234						1,192
Total Wisconsin Power and Light Company common equity			3,713						3,491
Total liabilities and equity			$9,074						$8,987

Refer to accompanying Combined Notes to Condensed Consolidated Financial Statements.

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WISCONSIN POWER AND LIGHT COMPANY

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED)

			For the Three Months
			Ended March 31,
			2023						2022
			(in millions)
Cash flows from operating activities:
Net income			$88						$92
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation and amortization			68						70
Other			(12)						(5)
Other changes in assets and liabilities:
Accounts receivable			19						(23)
Gas stored underground			35						26
Derivative assets			46						(42)
Regulatory assets			(37)						10
Accounts payable			(48)						(24)
Derivative liabilities			28						(2)
Regulatory liabilities			(35)						32
Accrued taxes			19						21
Other			14						12
Net cash flows from operating activities			185						167
Cash flows used for investing activities:
Construction and acquisition expenditures			(316)						(212)
Proceeds from sale of partial ownership interest in West Riverside			25						—
Other			(4)						(5)
Net cash flows used for investing activities			(295)						(217)
Cash flows from financing activities:
Common stock dividends			(46)						(44)
Capital contributions from parent			180						180
Proceeds from issuance of long-term debt			297						—
Net change in commercial paper			(230)						(79)
Other			(10)						(5)
Net cash flows from financing activities			191						52
Net increase in cash, cash equivalents and restricted cash			81						2
Cash, cash equivalents and restricted cash at beginning of period			5						2
Cash, cash equivalents and restricted cash at end of period			$86						$4
Supplemental cash flows information:
Cash paid during the period for:
Interest			($40)						($23)
Significant non-cash investing and financing activities:
Accrued capital expenditures			$152						$104

Refer to accompanying Combined Notes to Condensed Consolidated Financial Statements.

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ALLIANT ENERGY CORPORATION

INTERSTATE POWER AND LIGHT COMPANY

WISCONSIN POWER AND LIGHT COMPANY

COMBINED NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (UNAUDITED)

NOTE 1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

NOTE 1(a) General - The interim unaudited Financial Statements included herein have been prepared pursuant to the rules and regulations of the SEC. Accordingly, certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted, although management believes that the disclosures are adequate to make the information presented not misleading. These Financial Statements should be read in conjunction with the financial statements and the notes thereto included in the 2022 Form 10-K.

In the opinion of management, all adjustments, which unless otherwise noted are normal and recurring in nature, necessary for a fair presentation of the results of operations, financial position and cash flows have been made. Results for the three months ended March 31, 2023 are not necessarily indicative of results that may be expected for the year ending December 31, 2023.

A change in management’s estimates or assumptions could have a material impact on financial condition and results of operations during the period in which such change occurred. Certain prior period amounts in the Financial Statements and Notes have been reclassified to conform to the current period presentation for comparative purposes.

NOTE 1(b) Cash and Cash Equivalents - At March 31, 2023, Alliant Energy’s, IPL’s and WPL’s cash and cash equivalents included $148 million, $30 million and $83 million of money market fund investments, respectively, with interest rates of 5%.

NOTE 2. REGULATORY MATTERS

Regulatory Assets and Regulatory Liabilities -

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

			Alliant Energy												IPL												WPL
			March 31, 2023						December 31, 2022						March 31, 2023						December 31, 2022						March 31, 2023						December 31, 2022
Tax-related			$942						$929						$857						$848						$85						$81
Pension and OPEB costs			385						392						193						197						192						195
Asset retirement obligations			156						151						115						110						41						41
Commodity cost recovery			152						160						4						1						148						159
Derivatives			101						84						37						48						64						36
Assets retired early			67						70						51						53						16						17
IPL’s Duane Arnold Energy Center PPA amendment			60						66						60						66						—						—
WPL’s Western Wisconsin gas distribution expansion investments			48						48						—						—						48						48
Other			169						146						66						63						103						83
			$2,080						$2,046						$1,383						$1,386						$697						$660

Derivatives - Refer to Note 11 for discussion of changes in Alliant Energy’s, IPL’s and WPL’s derivative liabilities/assets during the three months ended March 31, 2023, which result in comparable changes to regulatory assets/liabilities on the balance sheets.

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

			Alliant Energy												IPL												WPL
			March 31, 2023						December 31, 2022						March 31, 2023						December 31, 2022						March 31, 2023						December 31, 2022
Tax-related			$575						$579						$302						$303						$273						$276
Cost of removal obligations			403						398						261						259						142						139
Derivatives			117						210						64						115						53						95
Electric transmission cost recovery			26						20						19						10						7						10
WPL’s West Riverside liquidated damages			24						32						—						—						24						32
Commodity cost recovery			22						40						8						38						14						2
Other			64						45						43						29						21						16
			$1,231						$1,324						$697						$754						$534						$570

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NOTE 3. PROPERTY, PLANT AND EQUIPMENT

In March 2023, Madison Gas and Electric Company acquired a partial ownership interest in West Riverside, and the related proceeds are included in “Proceeds from sale of partial ownership interest in West Riverside” in investing activities in Alliant Energy’s and WPL’s cash flow statements for the three months ended March 31, 2023. As a result of this transaction, WPL’s undivided current ownership interest in West Riverside is 87.6%.

NOTE 4. RECEIVABLES

NOTE 4(a) - Accounts Receivable - For the three months ended March 31, 2023, Alliant Energy’s, IPL’s and WPL’s gross write-offs for accounts receivable, which originated in 2022, were $5 million, $3 million and $2 million, respectively.

NOTE 4(b) - Sales of Accounts Receivable - IPL maintains a Receivables Purchase and Sale Agreement (Receivables Agreement) whereby it may sell its customer accounts receivables, unbilled revenues and certain other accounts receivables to a third party through wholly-owned and consolidated special purpose entities. In March 2023, IPL amended and extended through March 2024 the purchase commitment from the third party to which it sells its receivables. The transfers of receivables meet the criteria for sale accounting established by the transfer of financial assets accounting rules. As of March 31, 2023, IPL had $21 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 months ended March 31 were as follows (in millions):

			2023						2022
Maximum outstanding aggregate cash proceeds			$89						$36
Average outstanding aggregate cash proceeds			58						4

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

			March 31, 2023						December 31, 2022
Customer accounts receivable			$161						$145
Unbilled utility revenues			94						132
Receivables sold to third party			255						277
Less: cash proceeds			89						80
Deferred proceeds			166						197
Less: allowance for expected credit losses			13						12
Fair value of deferred proceeds			$153						$185

As of March 31, 2023, outstanding receivables past due under the Receivables Agreement were $26 million. Additional attributes of IPL’s receivables sold under the Receivables Agreement for the three months ended March 31 were as follows (in millions):

			2023						2022
Collections			$591						$561
Write-offs, net of recoveries			2						2

NOTE 5. INVESTMENTS

Unconsolidated Equity Investments - Alliant Energy’s equity (income) loss from unconsolidated investments accounted for under the equity method of accounting for the three months ended March 31 was as follows (in millions):

			2023						2022
ATC Holdings			($13)						($11)
Other			(4)						(4)
			($17)						($15)

NOTE 6. COMMON EQUITY

Common Share Activity - A summary of Alliant Energy’s common stock activity was as follows:

Shares outstanding, January 1, 2023			251,134,966
Shareowner Direct Plan			118,488
Equity-based compensation plans			134,334
Shares outstanding, March 31, 2023			251,387,788

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Changes in Shareowners’ Equity - A summary of changes in shareowners’ equity was as follows (in millions):

Alliant Energy																					Accumulated						Shares in
									Additional												Other						Deferred												Total
			Common						Paid-In						Retained						Comprehensive						Compensation												Common
			Stock						Capital						Earnings						Loss						Trust												Equity
Three Months Ended March 31, 2023
Beginning balance, December 31, 2022			$3						$2,777						$3,509						$—						($13)												$6,276
Net income attributable to Alliant Energy common shareowners															163																								163
Common stock dividends ($0.4525 per share)															(113)																								(113)
Shareowner Direct Plan issuances									6																														6
Equity-based compensation plans and other									(3)																														(3)
Other comprehensive loss, net of tax																					(1)																		(1)
Ending balance, March 31, 2023			$3						$2,780						$3,559						($1)						($13)												$6,328

Three Months Ended March 31, 2022
Beginning balance, December 31, 2021			$3						$2,749						$3,250						$—						($12)												$5,990
Net income attributable to Alliant Energy common shareowners															192																								192
Common stock dividends ($0.4275 per share)															(107)																								(107)
Shareowner Direct Plan issuances									7																														7
Equity-based compensation plans and other									(6)						1																								(5)
Ending balance, March 31, 2022			$3						$2,750						$3,336						$—						($12)												$6,077

IPL									Additional																		Total
			Common						Paid-In						Retained												Common
			Stock						Capital						Earnings												Equity
Three Months Ended March 31, 2023
Beginning balance, December 31, 2022			$33						$2,807						$968												$3,808
Net income															72												72
Common stock dividends															(70)												(70)
Ending balance, March 31, 2023			$33						$2,807						$970												$3,810
Three Months Ended March 31, 2022
Beginning balance, December 31, 2021			$33						$2,807						$929												$3,769
Net income															87												87
Common stock dividends															(81)												(81)
Ending balance, March 31, 2022			$33						$2,807						$935												$3,775

WPL									Additional																		Total
			Common						Paid-In						Retained												Common
			Stock						Capital						Earnings												Equity
Three Months Ended March 31, 2023
Beginning balance, December 31, 2022			$66						$2,233						$1,192												$3,491
Net income															88												88
Common stock dividends															(46)												(46)
Capital contributions from parent									180																		180
Ending balance, March 31, 2023			$66						$2,413						$1,234												$3,713
Three Months Ended March 31, 2022
Beginning balance, December 31, 2021			$66						$1,704						$1,053												$2,823
Net income															92												92
Common stock dividends															(44)												(44)
Capital contributions from parent									180																		180
Ending balance, March 31, 2022			$66						$1,884						$1,101												$3,051

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NOTE 7. DEBT

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

March 31, 2023			Alliant Energy						IPL						WPL
Amount outstanding			$60						$—						$60
Weighted average interest rates			5.1%						N/A						5.1%
Available credit facility capacity			$940						$250						$240

			Alliant Energy																		WPL
Three Months Ended March 31			2023						2022																		2023						2022
Maximum amount outstanding (based on daily outstanding balances)			$793						$577																		$349						$252
Average amount outstanding (based on daily outstanding balances)			$574						$443																		$304						$205
Weighted average interest rates			4.8%						0.3%																		4.8%						0.3%

In January 2023, AEF received $50 million of proceeds from its December 2022 term loan credit agreement, which was classified as “Other short-term borrowings” on Alliant Energy’s balance sheet as of March 31, 2023.

NOTE 7(b) Long-term Debt - In March 2023, WPL issued $300 million of 4.95% debentures due 2033. The debentures were issued as green bonds, and an amount equal to or in excess of the net proceeds will be allocated or disbursed for the development and acquisition of WPL’s solar EGUs.

Convertible Senior Notes - In March 2023, Alliant Energy issued $575 million of 3.875% convertible senior notes (the Notes), which are senior unsecured obligations, and used the net proceeds from the issuance for general corporate purposes. The Notes will mature on March 15, 2026 unless earlier converted or repurchased, and no sinking fund is provided for the Notes. Alliant Energy may not redeem the Notes prior to the maturity date. Holders may convert their Notes at their option at any time prior to the close of business on the business day immediately preceding December 15, 2025 only under the following circumstances:

• during any calendar quarter commencing after the calendar quarter ending on June 30, 2023 (and only during such calendar quarter), if the last reported sale price of Alliant Energy’s common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day during such period;

• during the 5 business day period after any 10 consecutive trading day period (the “measurement period”) in which the trading price (as defined in the related Indenture) per $1,000 principal amount of Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of Alliant Energy’s common stock and the conversion rate on each such trading day; or

• upon the occurrence of specified corporate events.

On or after December 15, 2025 until the close of business on the business day immediately preceding the maturity date, holders may convert all or any portion of their Notes at any time, regardless of the foregoing circumstances. Upon conversion of the Notes, Alliant Energy will pay cash up to the aggregate principal amount of the Notes to be converted and pay or deliver, as the case may be, cash, shares of its common stock or a combination of cash and shares of its common stock, at its election, in respect of the remainder, if any, of its conversion obligation in excess of the aggregate principal amount of the Notes being converted.

The conversion rate will initially be 15.5461 shares of common stock per $1,000 principal amount of Notes (equivalent to an initial conversion price of approximately $64.32 per share of Alliant Energy’s common stock). The conversion rate will be subject to adjustment in some events but will not be adjusted for any accrued and unpaid interest. In addition, following certain corporate events that occur prior to the maturity date, Alliant Energy will, in certain circumstances, increase the conversion rate for a holder who elects to convert its Notes in connection with such a corporate event.

If Alliant Energy undergoes a fundamental change (as defined in the related Indenture), then, subject to certain conditions, holders of the Notes may require Alliant Energy to repurchase for cash all or any portion of its Notes at a repurchase price equal to 100% of the principal amount of the Notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date.

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In March 2023, the conditions allowing holders of the Notes to convert during March 2023 were not met, and as a result, the Notes were classified as “Long-term debt, net” on Alliant Energy’s balance sheet as of March 31, 2023. As of March 31, 2023, the net carrying amount of the Notes was $565 million, with unamortized debt issuance costs of $10 million, and the estimated fair value (Level 2) of the Notes was $595 million. As of March 31, 2023, there were no shares of Alliant Energy’s common stock related to the potential conversion of the Notes included in diluted EPS based on Alliant Energy’s average stock prices and the relevant terms of the Notes.

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 March 31			2023						2022						2023						2022						2023						2022
Electric Utility:
Retail - residential			$285						$293						$143						$150						$142						$143
Retail - commercial			185						188						112						118						73						70
Retail - industrial			216						211						107						111						109						100
Wholesale			46						47						12						15						34						32
Bulk power and other			36						34						14						6						22						28
Total Electric Utility			768						773						388						400						380						373
Gas Utility:
Retail - residential			167						158						93						85						74						73
Retail - commercial			88						82						44						40						44						42
Retail - industrial			7						8						4						5						3						3
Transportation/other			14						14						9						9						5						5
Total Gas Utility			276						262						150						139						126						123
Other Utility:
Steam			10						9						10						9						—						—
Other utility			1						2						1						2						—						—
Total Other Utility			11						11						11						11						—						—
Non-Utility and Other:
Travero and other			22						22						—						—						—						—
Total Non-Utility and Other			22						22						—						—						—						—
Total revenues			$1,077						$1,068						$549						$550						$506						$496

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.

			Alliant Energy												IPL												WPL
			2023						2022																		2023						2022																		2023						2022
Overall income tax rate			(1%)						4%																		(18%)						(14%)																		12%						19%

Deferred Tax Assets and Liabilities -

Carryforwards - At March 31, 2023, the carryforwards and expiration dates were estimated as follows (in millions):

			Range of Expiration Dates						Alliant Energy						IPL						WPL
State net operating losses			2025-2043						$535						$12						$1
Federal tax credits			2027-2043						698						468						218

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 months ended March 31 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.

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			Defined Benefit Pension Plans												OPEB Plans
Alliant Energy			2023						2022																		2023						2022
Service cost			$1						$2																		$1						$1
Interest cost			11						9																		2						1
Expected return on plan assets			(13)						(17)																		(1)						(1)
Amortization of actuarial loss			7						8																		—						1
			$6						$2																		$2						$2

			Defined Benefit Pension Plans												OPEB Plans
IPL			2023						2022																		2023						2022
Service cost			$1						$2																		$—						$—
Interest cost			5						4																		1						1
Expected return on plan assets			(7)						(8)																		(1)						(1)
Amortization of actuarial loss			3						3																		—						—
			$2						$1																		$—						$—

			Defined Benefit Pension Plans												OPEB Plans
WPL			2023						2022																		2023						2022
Service cost			$—						$1																		$—						$—
Interest cost			5						4																		1						1
Expected return on plan assets			(5)						(8)																		—						—
Amortization of actuarial loss			3						4																		—						—
			$3						$1																		$1						$1

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 months ended March 31 was as follows (in millions):

			Alliant Energy												IPL												WPL
			2023						2022																		2023						2022																		2023						2022
Compensation expense			$3						$4																		$2						$2																		$1						$2
Income tax benefits			1						1																		—						1																		—						—

As of March 31, 2023, Alliant Energy’s, IPL’s and WPL’s total unrecognized compensation cost related to share-based compensation awards was $18 million, $9 million and $8 million, respectively, which is expected to be recognized over a weighted average period of between 1 year and 2 years.

For the three months ended March 31, 2023, performance shares, performance restricted stock units and restricted stock units were granted to key employees under existing plans as follows. These shares and units will be paid out in shares of common stock, and are therefore accounted for as equity awards.

									Weighted Average
			Grants						Grant Date Fair Value
Performance shares			100,055						$55.68
Performance restricted stock units			114,325						52.73
Restricted stock units			99,941						52.78

As of March 31, 2023, 170,209 shares were included in the calculation of diluted EPS related to the nonvested equity awards.

NOTE 11. DERIVATIVE INSTRUMENTS

Commodity Derivatives -

Notional Amounts - As of March 31, 2023, gross notional amounts and settlement/delivery years related to outstanding swap contracts, option contracts, physical forward contracts and FTRs that were accounted for as commodity derivative instruments were as follows (units in thousands):

			Electricity												FTRs												Natural Gas												Coal
			MWhs						Years						MWhs						Years						Dths						Years						Tons						Years
Alliant Energy			922						2023-2025						3,276						2023						209,102						2023-2032						662						2023
IPL			391						2023-2025						1,338						2023						101,863						2023-2030						325						2023
WPL			531						2023						1,938						2023						107,239						2023-2032						337						2023

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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
			March 31, 2023						December 31, 2022						March 31, 2023						December 31, 2022						March 31, 2023						December 31, 2022
Current derivative assets			$28						$111						$17						$69						$11						$42
Non-current derivative assets			94						126						52						69						42						57
Current derivative liabilities			65						59						26						40						39						19
Non-current derivative liabilities			30						20						8						6						22						14

During the three months ended March 31, 2023, Alliant Energy’s, IPL’s and WPL’s current derivative assets decreased primarily due to settlements of natural gas, FTR and electricity contracts. Alliant Energy’s and WPL’s derivative liabilities increased primarily due to lower natural gas prices. IPL’s current derivative liabilities decreased primarily due to settlements of natural gas contracts. Based on IPL’s and WPL’s cost recovery mechanisms, the changes in the fair value of derivative liabilities/assets resulted in comparable changes to regulatory assets/liabilities on the balance sheets.

Credit Risk-related Contingent Features - Various agreements contain credit risk-related contingent features, including requirements to maintain certain credit ratings and/or limitations on liability positions under the agreements based on credit ratings. Certain of these agreements with credit risk-related contingency features are accounted for as derivative instruments. In the event of a material change in creditworthiness or if liability positions exceed certain contractual limits, credit support may need to be provided up to the amount of exposure under the contracts, or the contracts may need to be unwound and underlying liability positions paid. At March 31, 2023 and December 31, 2022, the aggregate fair value of all derivative instruments with credit risk-related contingent features in a net liability position was not materially different than amounts that would be required to be posted as credit support to counterparties by Alliant Energy, IPL or WPL if the most restrictive credit risk-related contingent features for derivative agreements in a net liability position were triggered.

Balance Sheet Offsetting - The fair value amounts of derivative instruments subject to a master netting arrangement are not netted by counterparty on the balance sheets. However, if the fair value amounts of derivative instruments by counterparty were netted, derivative assets and derivative liabilities related to commodity contracts would have been presented on the balance sheets as follows (in millions):

			Alliant Energy												IPL												WPL
			Gross												Gross												Gross
			(as reported)						Net						(as reported)						Net						(as reported)						Net
March 31, 2023
Derivative assets			$122						$89						$69						$51						$53						$38
Derivative liabilities			95						62						34						16						61						46
December 31, 2022
Derivative assets			237						193						138						108						99						85
Derivative liabilities			79						35						46						16						33						19

Fair value amounts recognized for the right to reclaim cash collateral (receivable) or the obligation to return cash collateral (payable) are not offset against fair value amounts recognized for derivative instruments executed with the same counterparty under the same master netting arrangement.

Interest Rate Derivative - In January 2023, AEF entered into a $300 million interest rate swap maturing in January 2026 to mitigate interest rate risk. Under the terms of the swap, AEF exchanged a variable interest rate for a fixed interest rate of 3.93% on a portion of its variable-rate term loan borrowings. The related interest rate derivative was valued based on quoted prices that utilize current market interest rate forecasts. As of March 31, 2023, $1 million of non-current interest rate derivative liabilities were recorded in “Other liabilities” on Alliant Energy’s balance sheet. This interest rate derivative was designated as a cash flow hedge, with changes in fair value recorded as other comprehensive income/loss. As of March 31, 2023, accumulated other comprehensive loss included $1 million of losses related to the interest rate swap. For the three months ended March 31, 2023, a $1 million reduction to interest expense was recorded in Alliant Energy’s income statement related to the interest rate swap.

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NOTE 12. FAIR VALUE MEASUREMENTS

Fair Value of Financial Instruments - The carrying amounts of current assets and current liabilities approximate fair value because of the short maturity of such financial instruments. Carrying amounts and related estimated fair values of other financial instruments were as follows (in millions):

Alliant Energy			March 31, 2023																														December 31, 2022
									Fair Value																														Fair Value
			Carrying						Level						Level						Level												Carrying						Level						Level						Level
			Amount						1						2						3						Total						Amount						1						2						3						Total
Assets:
Money market fund investments			$148						$148						$—						$—						$148						$10						$10						$—						$—						$10
Commodity derivatives			122						—						116						6						122						237						—						206						31						237
Deferred proceeds			153						—						—						153						153						185						—						—						185						185
Liabilities:
Commodity derivatives			95						—						84						11						95						79						—						67						12						79
Interest rate derivatives			1						—						1						—						1						—						—						—						—						—
Long-term debt (incl. current maturities)			8,940						—						8,461						1						8,462						8,076						—						7,338						1						7,339

IPL			March 31, 2023																														December 31, 2022
									Fair Value																														Fair Value
			Carrying						Level						Level						Level												Carrying						Level						Level						Level
			Amount						1						2						3						Total						Amount						1						2						3						Total
Assets:
Money market fund investments			$30						$30						$—						$—						$30						$10						$10						$—						$—						$10
Commodity derivatives			69						—						63						6						69						138						—						111						27						138
Deferred proceeds			153						—						—						153						153						185						—						—						185						185
Liabilities:
Commodity derivatives			34						—						28						6						34						46						—						35						11						46
Long-term debt			3,647						—						3,335						—						3,335						3,646						—						3,228						—						3,228

WPL			March 31, 2023																														December 31, 2022
									Fair Value																														Fair Value
			Carrying						Level						Level						Level												Carrying						Level						Level						Level
			Amount						1						2						3						Total						Amount						1						2						3						Total
Assets:
Money market fund investments			$83						$83						$—						$—						$83						$—						$—						$—						$—						$—
Commodity derivatives			53						—						53						—						53						99						—						95						4						99
Liabilities:
Commodity derivatives			61						—						56						5						61						33						—						32						1						33
Long-term debt			3,067						—						2,939						—						2,939						2,770						—						2,542						—						2,542

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

Alliant Energy			Commodity Contract Derivative
			Assets and (Liabilities), net												Deferred Proceeds
Three Months Ended March 31			2023						2022						2023						2022
Beginning balance, January 1			$19						$29						$185						$214
Total net losses included in changes in net assets (realized/unrealized)			(4)						(6)						—						—
Settlements (a)			(20)						(13)						(32)						13
Ending balance, March 31			($5)						$10						$153						$227
The amount of total net losses for the period included in changes in net assets attributable to the change in unrealized losses relating to assets and liabilities held at March 31			($4)						($5)						$—						$—

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IPL			Commodity Contract Derivative
			Assets and (Liabilities), net												Deferred Proceeds
Three Months Ended March 31			2023						2022						2023						2022
Beginning balance, January 1			$16						$18						$185						$214
Total net gains (losses) included in changes in net assets (realized/unrealized)			1						(4)						—						—
Settlements (a)			(17)						(7)						(32)						13
Ending balance, March 31			$—						$7						$153						$227
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 March 31			$1						($4)						$—						$—

WPL			Commodity Contract Derivative
			Assets and (Liabilities), net
Three Months Ended March 31			2023						2022
Beginning balance, January 1			$3						$11
Total net losses included in changes in net assets (realized/unrealized)			(5)						(2)
Settlements			(3)						(6)
Ending balance, March 31			($5)						$3
The amount of total net losses for the period included in changes in net assets attributable to the change in unrealized losses relating to assets and liabilities held at March 31			($5)						($1)

(a)Settlements related to deferred proceeds are due to the change in the carrying amount of receivables sold less the allowance for expected credit losses associated with the receivables sold and cash amounts received from the receivables sold.

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

			Alliant Energy												IPL												WPL
			Excluding FTRs						FTRs						Excluding FTRs						FTRs						Excluding FTRs						FTRs
March 31, 2023			($10)						$5						($4)						$4						($6)						$1
December 31, 2022			(10)						29						(9)						25						(1)						4

NOTE 13. COMMITMENTS AND CONTINGENCIES

NOTE 13(a) Capital Purchase Commitments - Various contractual obligations contain minimum future commitments related to capital expenditures for certain construction projects, including IPL’s and WPL’s expansion of solar generation. At March 31, 2023, Alliant Energy’s, IPL’s and WPL’s minimum future commitments for these projects were $252 million, $40 million and $212 million, respectively.

NOTE 13(b) Other Purchase Commitments - Various commodity supply, transportation and storage contracts help meet obligations to provide electricity and natural gas to utility customers. In addition, there are various purchase commitments associated with other goods and services. At March 31, 2023, related minimum future commitments were as follows (in millions):

			Alliant Energy						IPL						WPL
Natural gas			$1,280						$565						$715
Coal			175						89						86
Other (a)			113						53						26
			$1,568						$707						$827

(a)Includes individual commitments incurred during the normal course of business that exceeded $1 million at March 31, 2023.

NOTE 13(c) Guarantees and Indemnifications -

Whiting Petroleum - Whiting Petroleum is an independent oil and gas company. In 2004, Alliant Energy sold its remaining interest in Whiting Petroleum. Alliant Energy Resources, LLC, as the successor to a predecessor entity that owned Whiting Petroleum, and a wholly-owned subsidiary of AEF, continues to guarantee the partnership obligations of an affiliate of Whiting Petroleum under multiple general partnership agreements in the oil and gas industry. The guarantees do not include a maximum limit. Based on information made available to Alliant Energy by Whiting Petroleum, the Whiting Petroleum affiliate holds an approximate 6% share in the partnerships, and currently known obligations include costs associated with the future

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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 March 31, 2023, the currently known partnership obligations for the abandonment obligations are estimated at $58 million, which represents Alliant Energy’s currently estimated maximum exposure under the guarantees. Alliant Energy estimates its expected loss to be a portion of the $58 million of known partnership abandonment obligations of the Whiting Petroleum affiliate and the other partners. Alliant Energy is not aware of any material liabilities related to these guarantees that it is probable that it will be obligated to pay; however, as of both March 31, 2023 and December 31, 2022, a liability of $5 million is recorded in “Other liabilities” on Alliant Energy’s balance sheets for expected credit losses related to the contingent obligations that are in the scope of these guarantees.

Whiting Petroleum completed a business combination with Oasis Petroleum Inc. in July 2022. The combined operations are now known as Chord Energy Corporation. The business combination is not expected to affect the scope of the Whiting Petroleum affiliate’s obligations to Alliant Energy or Alliant Energy’s related guarantees.

Non-utility Wind Farm in Oklahoma - In 2017, a wholly-owned subsidiary of AEF acquired a cash equity ownership interest in a non-utility wind farm located in Oklahoma. The wind farm provides electricity to a third party under a long-term PPA. Alliant Energy provided a parent guarantee of its subsidiary’s indemnification obligations under the related operating agreement and PPA. Alliant Energy’s obligations under the operating agreement were $59 million as of March 31, 2023 and will reduce annually until expiring in July 2047. Alliant Energy’s obligations under the PPA are subject to a maximum limit of $17 million and expire in December 2031, subject to potential extension. Alliant Energy is not aware of any material liabilities related to this guarantee that it is probable that it will be obligated to pay and therefore has not recognized any material liabilities related to this guarantee as of March 31, 2023 and December 31, 2022.

NOTE 13(d) Environmental Matters -

Manufactured Gas Plant (MGP) Sites - IPL and WPL have current or previous ownership interests in various sites that are previously associated with the production of gas for which IPL and WPL have, or may have in the future, liability for investigation, remediation and monitoring costs. IPL and WPL are working pursuant to the requirements of various federal and state agencies to investigate, mitigate, prevent and remediate, where necessary, the environmental impacts to property, including natural resources, at and around these former MGP sites in order to protect public health and the environment. At March 31, 2023, estimated future costs expected to be incurred for the investigation, remediation and monitoring of the MGP sites, as well as environmental liabilities recorded on the balance sheets for these sites, which are not discounted, were as follows (in millions):

			Alliant Energy												IPL												WPL
Range of estimated future costs			$10			-			$37						$6			-			$12						$4			-			$25
Current and non-current environmental liabilities			$18												$8												$10

IPL Consent Decree - In 2015, the U.S. District Court for the Northern District of Iowa approved a Consent Decree that IPL entered into with the EPA, the Sierra Club, the State of Iowa and Linn County in Iowa, thereby resolving potential Clean Air Act issues associated with emissions from IPL’s coal-fired generating facilities in Iowa. IPL has completed various requirements under the Consent Decree. IPL’s remaining requirements include fuel switching or retiring Prairie Creek Units 1 and 3 by December 31, 2025. Alliant Energy and IPL currently expect to recover material costs incurred by IPL related to compliance with the terms of the Consent Decree from IPL’s electric customers.

Other Environmental Contingencies - In addition to the environmental liabilities discussed above, various environmental rules are monitored that may have a significant impact on future operations. Several of these environmental rules are subject to legal challenges, reconsideration and/or other uncertainties. Given uncertainties regarding the outcome, timing and compliance plans for these environmental matters, the complete financial impact of each of these rules is not able to be determined; however, future capital investments and/or modifications to EGUs and electric and gas distribution systems to comply with certain of these rules could be significant. Specific current, proposed or potential environmental matters include, among others: Cross-State Air Pollution Rule, Effluent Limitation Guidelines, Coal Combustion Residuals Rule, and various legislation and EPA regulations to monitor and regulate the emission of greenhouse gases, including the Clean Air Act.

NOTE 13(e) MISO Transmission Owner Return on Equity Complaints - A group of stakeholders, including MISO cooperative and municipal utilities, previously filed complaints with the Federal Energy Regulatory Commission (FERC) requesting a reduction to the base return on equity authorized for MISO transmission owners, including ITC Midwest LLC and ATC. In 2019, FERC issued an order on the previously filed complaints and reduced the base return on equity authorized for the MISO transmission owners to 9.88% for November 12, 2013 through February 11, 2015, and subsequent to September 28, 2016. In 2020, FERC issued orders in response to various rehearing requests and increased the base return on equity authorized for the MISO transmission owners from 9.88% to 10.02% for November 12, 2013 through February 11, 2015, and subsequent to September 28, 2016. In August 2022, the U.S. Court of Appeals for the District of Columbia Circuit vacated FERC’s prior orders that established the base return on equity authorized for the MISO transmission owners and remanded the cases to FERC for further proceedings, which may result in additional changes to the base return on equity authorized for

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the MISO transmission owners. Any further changes in FERC’s decisions may have an impact on Alliant Energy’s share of ATC’s future earnings and customer costs.

NOTE 14. SEGMENTS OF BUSINESS

Certain financial information relating to Alliant Energy’s, IPL’s and WPL’s business segments is as follows. Intersegment revenues were not material to their respective operations.

Alliant Energy																											ATC Holdings,						Alliant
			Utility																								Non-Utility,						Energy
			Electric						Gas						Other						Total						Parent and Other						Consolidated
			(in millions)
Three Months Ended March 31, 2023
Revenues			$768						$276						$11						$1,055						$22						$1,077
Operating income			163						50						4						217						5						222
Net income attributable to Alliant Energy common shareowners																					160						3						163
Three Months Ended March 31, 2022
Revenues			$773						$262						$11						$1,046						$22						$1,068
Operating income			181						57						3						241						7						248
Net income attributable to Alliant Energy common shareowners																					179						13						192

IPL			Electric						Gas						Other						Total
			(in millions)
Three Months Ended March 31, 2023
Revenues			$388						$150						$11						$549
Operating income			66						27						3						96
Net income																					72
Three Months Ended March 31, 2022
Revenues			$400						$139						$11						$550
Operating income			75						32						3						110
Net income																					87

WPL			Electric						Gas						Other						Total
			(in millions)
Three Months Ended March 31, 2023
Revenues			$380						$126						$—						$506
Operating income			97						23						1						121
Net income																					88
Three Months Ended March 31, 2022
Revenues			$373						$123						$—						$496
Operating income			106						25						—						131
Net income																					92

NOTE 15. RELATED PARTIES

Service Agreements - Pursuant to service agreements, IPL and WPL receive various administrative and general services from an affiliate, Corporate Services. These services are billed to IPL and WPL at cost based on expenses incurred by Corporate Services for the benefit of IPL and WPL, respectively. These costs consisted primarily of employee compensation and benefits, fees associated with various professional services, depreciation and amortization of property, plant and equipment, and a return on net assets. Corporate Services also acts as agent on behalf of IPL and WPL pursuant to the service agreements. As agent, Corporate Services enters into energy, capacity, ancillary services, and transmission sale and purchase transactions within MISO. Corporate Services assigns such sales and purchases among IPL and WPL based on statements received from MISO. The amounts billed for services provided, sales credited and purchases for the three months ended March 31 were as follows (in millions):

			IPL												WPL
			2023						2022																		2023						2022
Corporate Services billings			$40						$40																		$36						$36
Sales credited			7						—																		13						18
Purchases billed			93						94																		15						22

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

			IPL												WPL
			March 31, 2023						December 31, 2022						March 31, 2023						December 31, 2022
Net payables to Corporate Services			$110						$103						$65						$56

ATC - Pursuant to various agreements, WPL receives a range of transmission services from ATC. WPL provides operation, maintenance, and construction services to ATC. WPL and ATC also bill each other for use of shared facilities owned by each party. The related amounts billed between the parties for the three months ended March 31 were as follows (in millions):

			2023						2022
ATC billings to WPL			$34						$34
WPL billings to ATC			6						3

WPL owed ATC net amounts of $9 million as of March 31, 2023 and $10 million as of December 31, 2022.