Retirement Benefits

6 Months Ended

Jun. 30, 2021

Defined Benefit Plan Disclosure [Line Items]

Retirement Benefits

Retirement BenefitsCMS Energy and Consumers provide pension, OPEB, and other retirement benefits to employees under a number of different plans.

Costs: Presented in the following table are the costs (credits) and other changes in plan assets and benefit obligations incurred in CMS Energy’s and Consumers’ retirement benefits plans:

In Millions
	DB Pension Plans												OPEB Plan
	Three Months Ended						Six Months Ended						Three Months Ended						Six Months Ended
June 30	2021			2020			2021			2020			2021			2020			2021			2020
CMS Energy, including Consumers
Net periodic cost (credit)
Service cost		$	13		$	13		$	27		$	25		$	5		$	4		$	9		$	8
Interest cost		15			20			30			41			5			9			11			17
Expected return on plan assets		(52)			(48)			(104)			(96)			(27)			(25)			(54)			(50)
Amortization of:
Net loss		26			22			51			44			2			3			4			7
Prior service cost (credit)		1			1			2			1			(13)			(14)			(26)			(28)
Settlement loss		2			—			3			—			—			—			—			—
Net periodic cost (credit)		$	5		$	8		$	9		$	15		$	(28)		$	(23)		$	(56)		$	(46)
Consumers
Net periodic cost (credit)
Service cost		$	13		$	12		$	26		$	24		$	5		$	4		$	9		$	8
Interest cost		14			19			28			39			5			8			11			16
Expected return on plan assets		(49)			(46)			(98)			(91)			(26)			(24)			(51)			(47)
Amortization of:
Net loss		24			21			49			42			2			3			4			7
Prior service cost (credit)		1			1			2			1			(13)			(13)			(26)			(27)
Settlement loss		2			—			3			—			—			—			—			—
Net periodic cost (credit)		$	5		$	7		$	10		$	15		$	(27)		$	(22)		$	(53)		$	(43)

Consumers Energy Company

Defined Benefit Plan Disclosure [Line Items]

Retirement Benefits

Retirement BenefitsCMS Energy and Consumers provide pension, OPEB, and other retirement benefits to employees under a number of different plans.

Costs: Presented in the following table are the costs (credits) and other changes in plan assets and benefit obligations incurred in CMS Energy’s and Consumers’ retirement benefits plans:

In Millions
	DB Pension Plans												OPEB Plan
	Three Months Ended						Six Months Ended						Three Months Ended						Six Months Ended
June 30	2021			2020			2021			2020			2021			2020			2021			2020
CMS Energy, including Consumers
Net periodic cost (credit)
Service cost		$	13		$	13		$	27		$	25		$	5		$	4		$	9		$	8
Interest cost		15			20			30			41			5			9			11			17
Expected return on plan assets		(52)			(48)			(104)			(96)			(27)			(25)			(54)			(50)
Amortization of:
Net loss		26			22			51			44			2			3			4			7
Prior service cost (credit)		1			1			2			1			(13)			(14)			(26)			(28)
Settlement loss		2			—			3			—			—			—			—			—
Net periodic cost (credit)		$	5		$	8		$	9		$	15		$	(28)		$	(23)		$	(56)		$	(46)
Consumers
Net periodic cost (credit)
Service cost		$	13		$	12		$	26		$	24		$	5		$	4		$	9		$	8
Interest cost		14			19			28			39			5			8			11			16
Expected return on plan assets		(49)			(46)			(98)			(91)			(26)			(24)			(51)			(47)
Amortization of:
Net loss		24			21			49			42			2			3			4			7
Prior service cost (credit)		1			1			2			1			(13)			(13)			(26)			(27)
Settlement loss		2			—			3			—			—			—			—			—
Net periodic cost (credit)		$	5		$	7		$	10		$	15		$	(27)		$	(22)		$	(53)		$	(43)