Common Equity (Tables)

6 Months Ended

Jun. 30, 2025

Schedule of Capitalization, Equity [Line Items]

A summary of Alliant Energy’s common stock activity was as follows:


Shares outstanding, January 1, 2025			256,690,222


Shareowner Direct Plan			192,628
Equity-based compensation plans			86,377

Shares outstanding, June 30, 2025			256,969,227

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	Income	Trust	Equity
Three Months Ended June 30, 2025
Beginning balance, March 31, 2025	$3	$3,066	$4,037	$—	($13)	$7,093
Net income attributable to Alliant Energy common shareowners			174			174
Common stock dividends ($0.5075 per share)			(131)			(131)
Shareowner Direct Plan issuances		6				6
Equity-based compensation plans and other		3				3




Ending balance, June 30, 2025	$3	$3,075	$4,080	$—	($13)	$7,145
Three Months Ended June 30, 2024
Beginning balance, March 31, 2024	$3	$3,033	$3,791	$2	($12)	$6,817
Net income attributable to Alliant Energy common shareowners			87			87
Common stock dividends ($0.48 per share)			(123)			(123)
Shareowner Direct Plan issuances		6				6
Equity-based compensation plans and other		3				3



Other comprehensive income, net of tax				1		1
Ending balance, June 30, 2024	$3	$3,042	$3,755	$3	($12)	$6,791




Alliant Energy				Accumulated	Shares in
		Additional		Other	Deferred	Total
	Common	Paid-In	Retained	Comprehensive	Compensation	Common
	Stock	Capital	Earnings	Income (Loss)	Trust	Equity
Six Months Ended June 30, 2025
Beginning balance, December 31, 2024	$3	$3,060	$3,954	$1	($14)	$7,004
Net income attributable to Alliant Energy common shareowners			387			387
Common stock dividends ($1.015 per share)			(261)			(261)
Shareowner Direct Plan issuances		12				12
Equity-based compensation plans and other		3			1	4



Other comprehensive loss, net of tax				(1)		(1)
Ending balance, June 30, 2025	$3	$3,075	$4,080	$—	($13)	$7,145
Six Months Ended June 30, 2024
Beginning balance, December 31, 2023	$3	$3,030	$3,756	$1	($13)	$6,777
Net income attributable to Alliant Energy common shareowners			245			245
Common stock dividends ($0.96 per share)			(246)			(246)
Shareowner Direct Plan issuances		12				12
Equity-based compensation plans and other					1	1



Other comprehensive income, net of tax				2		2
Ending balance, June 30, 2024	$3	$3,042	$3,755	$3	($12)	$6,791



IPL		Additional		Total
	Common	Paid-In	Retained	Common
	Stock	Capital	Earnings	Equity
Three Months Ended June 30, 2025
Beginning balance, March 31, 2025	$33	$3,257	$1,237	$4,527
Net income			98	98
Common stock dividends			(90)	(90)
Capital contributions from parent		100		100
Ending balance, June 30, 2025	$33	$3,357	$1,245	$4,635
Three Months Ended June 30, 2024
Beginning balance, March 31, 2024	$33	$2,937	$1,067	$4,037
Net income			18	18
Common stock dividends			(50)	(50)
Capital contributions from parent		75		75
Ending balance, June 30, 2024	$33	$3,012	$1,035	$4,080




IPL		Additional		Total
	Common	Paid-In	Retained	Common
	Stock	Capital	Earnings	Equity
Six Months Ended June 30, 2025
Beginning balance, December 31, 2024	$33	$3,212	$1,216	$4,461
Net income			209	209
Common stock dividends			(180)	(180)
Capital contributions from parent		145		145
Ending balance, June 30, 2025	$33	$3,357	$1,245	$4,635
Six Months Ended June 30, 2024
Beginning balance, December 31, 2023	$33	$2,887	$1,054	$3,974
Net income			81	81
Common stock dividends			(100)	(100)
Capital contributions from parent		125		125
Ending balance, June 30, 2024	$33	$3,012	$1,035	$4,080



WPL		Additional		Total
	Common	Paid-In	Retained	Common
	Stock	Capital	Earnings	Equity
Three Months Ended June 30, 2025
Beginning balance, March 31, 2025	$66	$2,533	$1,537	$4,136
Net income			87	87
Common stock dividends			(43)	(43)




Ending balance, June 30, 2025	$66	$2,533	$1,581	$4,180
Three Months Ended June 30, 2024
Beginning balance, March 31, 2024	$66	$2,533	$1,396	$3,995
Net income			64	64
Common stock dividends			(49)	(49)




Ending balance, June 30, 2024	$66	$2,533	$1,411	$4,010




WPL		Additional		Total
	Common	Paid-In	Retained	Common
	Stock	Capital	Earnings	Equity
Six Months Ended June 30, 2025
Beginning balance, December 31, 2024	$66	$2,533	$1,502	$4,101
Net income			198	198
Common stock dividends			(119)	(119)




Ending balance, June 30, 2025	$66	$2,533	$1,581	$4,180
Six Months Ended June 30, 2024
Beginning balance, December 31, 2023	$66	$2,478	$1,353	$3,897
Net income			156	156
Common stock dividends			(98)	(98)
Capital contributions from parent		55		55



Ending balance, June 30, 2024	$66	$2,533	$1,411	$4,010

IPL [Member]

Schedule of Capitalization, Equity [Line Items]

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	Income	Trust	Equity
Three Months Ended June 30, 2025
Beginning balance, March 31, 2025	$3	$3,066	$4,037	$—	($13)	$7,093
Net income attributable to Alliant Energy common shareowners			174			174
Common stock dividends ($0.5075 per share)			(131)			(131)
Shareowner Direct Plan issuances		6				6
Equity-based compensation plans and other		3				3




Ending balance, June 30, 2025	$3	$3,075	$4,080	$—	($13)	$7,145
Three Months Ended June 30, 2024
Beginning balance, March 31, 2024	$3	$3,033	$3,791	$2	($12)	$6,817
Net income attributable to Alliant Energy common shareowners			87			87
Common stock dividends ($0.48 per share)			(123)			(123)
Shareowner Direct Plan issuances		6				6
Equity-based compensation plans and other		3				3



Other comprehensive income, net of tax				1		1
Ending balance, June 30, 2024	$3	$3,042	$3,755	$3	($12)	$6,791




Alliant Energy				Accumulated	Shares in
		Additional		Other	Deferred	Total
	Common	Paid-In	Retained	Comprehensive	Compensation	Common
	Stock	Capital	Earnings	Income (Loss)	Trust	Equity
Six Months Ended June 30, 2025
Beginning balance, December 31, 2024	$3	$3,060	$3,954	$1	($14)	$7,004
Net income attributable to Alliant Energy common shareowners			387			387
Common stock dividends ($1.015 per share)			(261)			(261)
Shareowner Direct Plan issuances		12				12
Equity-based compensation plans and other		3			1	4



Other comprehensive loss, net of tax				(1)		(1)
Ending balance, June 30, 2025	$3	$3,075	$4,080	$—	($13)	$7,145
Six Months Ended June 30, 2024
Beginning balance, December 31, 2023	$3	$3,030	$3,756	$1	($13)	$6,777
Net income attributable to Alliant Energy common shareowners			245			245
Common stock dividends ($0.96 per share)			(246)			(246)
Shareowner Direct Plan issuances		12				12
Equity-based compensation plans and other					1	1



Other comprehensive income, net of tax				2		2
Ending balance, June 30, 2024	$3	$3,042	$3,755	$3	($12)	$6,791



IPL		Additional		Total
	Common	Paid-In	Retained	Common
	Stock	Capital	Earnings	Equity
Three Months Ended June 30, 2025
Beginning balance, March 31, 2025	$33	$3,257	$1,237	$4,527
Net income			98	98
Common stock dividends			(90)	(90)
Capital contributions from parent		100		100
Ending balance, June 30, 2025	$33	$3,357	$1,245	$4,635
Three Months Ended June 30, 2024
Beginning balance, March 31, 2024	$33	$2,937	$1,067	$4,037
Net income			18	18
Common stock dividends			(50)	(50)
Capital contributions from parent		75		75
Ending balance, June 30, 2024	$33	$3,012	$1,035	$4,080




IPL		Additional		Total
	Common	Paid-In	Retained	Common
	Stock	Capital	Earnings	Equity
Six Months Ended June 30, 2025
Beginning balance, December 31, 2024	$33	$3,212	$1,216	$4,461
Net income			209	209
Common stock dividends			(180)	(180)
Capital contributions from parent		145		145
Ending balance, June 30, 2025	$33	$3,357	$1,245	$4,635
Six Months Ended June 30, 2024
Beginning balance, December 31, 2023	$33	$2,887	$1,054	$3,974
Net income			81	81
Common stock dividends			(100)	(100)
Capital contributions from parent		125		125
Ending balance, June 30, 2024	$33	$3,012	$1,035	$4,080



WPL		Additional		Total
	Common	Paid-In	Retained	Common
	Stock	Capital	Earnings	Equity
Three Months Ended June 30, 2025
Beginning balance, March 31, 2025	$66	$2,533	$1,537	$4,136
Net income			87	87
Common stock dividends			(43)	(43)




Ending balance, June 30, 2025	$66	$2,533	$1,581	$4,180
Three Months Ended June 30, 2024
Beginning balance, March 31, 2024	$66	$2,533	$1,396	$3,995
Net income			64	64
Common stock dividends			(49)	(49)




Ending balance, June 30, 2024	$66	$2,533	$1,411	$4,010




WPL		Additional		Total
	Common	Paid-In	Retained	Common
	Stock	Capital	Earnings	Equity
Six Months Ended June 30, 2025
Beginning balance, December 31, 2024	$66	$2,533	$1,502	$4,101
Net income			198	198
Common stock dividends			(119)	(119)




Ending balance, June 30, 2025	$66	$2,533	$1,581	$4,180
Six Months Ended June 30, 2024
Beginning balance, December 31, 2023	$66	$2,478	$1,353	$3,897
Net income			156	156
Common stock dividends			(98)	(98)
Capital contributions from parent		55		55



Ending balance, June 30, 2024	$66	$2,533	$1,411	$4,010

WPL [Member]

Schedule of Capitalization, Equity [Line Items]

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	Income	Trust	Equity
Three Months Ended June 30, 2025
Beginning balance, March 31, 2025	$3	$3,066	$4,037	$—	($13)	$7,093
Net income attributable to Alliant Energy common shareowners			174			174
Common stock dividends ($0.5075 per share)			(131)			(131)
Shareowner Direct Plan issuances		6				6
Equity-based compensation plans and other		3				3




Ending balance, June 30, 2025	$3	$3,075	$4,080	$—	($13)	$7,145
Three Months Ended June 30, 2024
Beginning balance, March 31, 2024	$3	$3,033	$3,791	$2	($12)	$6,817
Net income attributable to Alliant Energy common shareowners			87			87
Common stock dividends ($0.48 per share)			(123)			(123)
Shareowner Direct Plan issuances		6				6
Equity-based compensation plans and other		3				3



Other comprehensive income, net of tax				1		1
Ending balance, June 30, 2024	$3	$3,042	$3,755	$3	($12)	$6,791




Alliant Energy				Accumulated	Shares in
		Additional		Other	Deferred	Total
	Common	Paid-In	Retained	Comprehensive	Compensation	Common
	Stock	Capital	Earnings	Income (Loss)	Trust	Equity
Six Months Ended June 30, 2025
Beginning balance, December 31, 2024	$3	$3,060	$3,954	$1	($14)	$7,004
Net income attributable to Alliant Energy common shareowners			387			387
Common stock dividends ($1.015 per share)			(261)			(261)
Shareowner Direct Plan issuances		12				12
Equity-based compensation plans and other		3			1	4



Other comprehensive loss, net of tax				(1)		(1)
Ending balance, June 30, 2025	$3	$3,075	$4,080	$—	($13)	$7,145
Six Months Ended June 30, 2024
Beginning balance, December 31, 2023	$3	$3,030	$3,756	$1	($13)	$6,777
Net income attributable to Alliant Energy common shareowners			245			245
Common stock dividends ($0.96 per share)			(246)			(246)
Shareowner Direct Plan issuances		12				12
Equity-based compensation plans and other					1	1



Other comprehensive income, net of tax				2		2
Ending balance, June 30, 2024	$3	$3,042	$3,755	$3	($12)	$6,791



IPL		Additional		Total
	Common	Paid-In	Retained	Common
	Stock	Capital	Earnings	Equity
Three Months Ended June 30, 2025
Beginning balance, March 31, 2025	$33	$3,257	$1,237	$4,527
Net income			98	98
Common stock dividends			(90)	(90)
Capital contributions from parent		100		100
Ending balance, June 30, 2025	$33	$3,357	$1,245	$4,635
Three Months Ended June 30, 2024
Beginning balance, March 31, 2024	$33	$2,937	$1,067	$4,037
Net income			18	18
Common stock dividends			(50)	(50)
Capital contributions from parent		75		75
Ending balance, June 30, 2024	$33	$3,012	$1,035	$4,080




IPL		Additional		Total
	Common	Paid-In	Retained	Common
	Stock	Capital	Earnings	Equity
Six Months Ended June 30, 2025
Beginning balance, December 31, 2024	$33	$3,212	$1,216	$4,461
Net income			209	209
Common stock dividends			(180)	(180)
Capital contributions from parent		145		145
Ending balance, June 30, 2025	$33	$3,357	$1,245	$4,635
Six Months Ended June 30, 2024
Beginning balance, December 31, 2023	$33	$2,887	$1,054	$3,974
Net income			81	81
Common stock dividends			(100)	(100)
Capital contributions from parent		125		125
Ending balance, June 30, 2024	$33	$3,012	$1,035	$4,080



WPL		Additional		Total
	Common	Paid-In	Retained	Common
	Stock	Capital	Earnings	Equity
Three Months Ended June 30, 2025
Beginning balance, March 31, 2025	$66	$2,533	$1,537	$4,136
Net income			87	87
Common stock dividends			(43)	(43)




Ending balance, June 30, 2025	$66	$2,533	$1,581	$4,180
Three Months Ended June 30, 2024
Beginning balance, March 31, 2024	$66	$2,533	$1,396	$3,995
Net income			64	64
Common stock dividends			(49)	(49)




Ending balance, June 30, 2024	$66	$2,533	$1,411	$4,010




WPL		Additional		Total
	Common	Paid-In	Retained	Common
	Stock	Capital	Earnings	Equity
Six Months Ended June 30, 2025
Beginning balance, December 31, 2024	$66	$2,533	$1,502	$4,101
Net income			198	198
Common stock dividends			(119)	(119)




Ending balance, June 30, 2025	$66	$2,533	$1,581	$4,180
Six Months Ended June 30, 2024
Beginning balance, December 31, 2023	$66	$2,478	$1,353	$3,897
Net income			156	156
Common stock dividends			(98)	(98)
Capital contributions from parent		55		55



Ending balance, June 30, 2024	$66	$2,533	$1,411	$4,010