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.


	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.

Benefit Plans

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.


	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.

Benefit Plans

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.


	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.