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Retirement Benefits | 3 Months Ended
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Mar. 31, 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 March 31 |  |  |  | 2021 | 2020 |  |  |  |  |  | 2021 | 2020 |
CMS Energy, including Consumers |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net periodic cost (credit) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Service cost |  |  |  |  |  |  | $ | 14 |  |  | $ | 12 |  |  |  |  |  |  |  |  |  |  | $ | 4 |  |  | $ | 4 |  |  |
Interest cost |  |  |  |  |  |  | 15 |  |  | 21 |  |  |  |  |  |  |  |  |  |  | 6 |  |  | 8 |  |  |
Expected return on plan assets |  |  |  |  |  |  | (52) |  |  | (48) |  |  |  |  |  |  |  |  |  |  | (27) |  |  | (25) |  |  |
Amortization of: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net loss |  |  |  |  |  |  | 25 |  |  | 22 |  |  |  |  |  |  |  |  |  |  | 2 |  |  | 4 |  |  |
Prior service cost (credit) |  |  |  |  |  |  | 1 |  |  | — |  |  |  |  |  |  |  |  |  |  | (13) |  |  | (14) |  |  |
Settlement loss |  |  |  |  |  |  | 1 |  |  | — |  |  |  |  |  |  |  |  |  |  | — |  |  | — |  |  |
Net periodic cost (credit) |  |  |  |  |  |  | $ | 4 |  |  | $ | 7 |  |  |  |  |  |  |  |  |  |  | $ | (28) |  |  | $ | (23) |  |  |
Consumers |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net periodic cost (credit) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Service cost |  |  |  |  |  |  | $ | 13 |  |  | $ | 12 |  |  |  |  |  |  |  |  |  |  | $ | 4 |  |  | $ | 4 |  |  |
Interest cost |  |  |  |  |  |  | 14 |  |  | 20 |  |  |  |  |  |  |  |  |  |  | 6 |  |  | 8 |  |  |
Expected return on plan assets |  |  |  |  |  |  | (49) |  |  | (45) |  |  |  |  |  |  |  |  |  |  | (25) |  |  | (23) |  |  |
Amortization of: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net loss |  |  |  |  |  |  | 25 |  |  | 21 |  |  |  |  |  |  |  |  |  |  | 2 |  |  | 4 |  |  |
Prior service cost (credit) |  |  |  |  |  |  | 1 |  |  | — |  |  |  |  |  |  |  |  |  |  | (13) |  |  | (14) |  |  |
Settlement loss |  |  |  |  |  |  | 1 |  |  | — |  |  |  |  |  |  |  |  |  |  | — |  |  | — |  |  |
Net periodic cost (credit) |  |  |  |  |  |  | $ | 5 |  |  | $ | 8 |  |  |  |  |  |  |  |  |  |  | $ | (26) |  |  | $ | (21) |  |  |
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 March 31 |  |  |  | 2021 | 2020 |  |  |  |  |  | 2021 | 2020 |
CMS Energy, including Consumers |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net periodic cost (credit) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Service cost |  |  |  |  |  |  | $ | 14 |  |  | $ | 12 |  |  |  |  |  |  |  |  |  |  | $ | 4 |  |  | $ | 4 |  |  |
Interest cost |  |  |  |  |  |  | 15 |  |  | 21 |  |  |  |  |  |  |  |  |  |  | 6 |  |  | 8 |  |  |
Expected return on plan assets |  |  |  |  |  |  | (52) |  |  | (48) |  |  |  |  |  |  |  |  |  |  | (27) |  |  | (25) |  |  |
Amortization of: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net loss |  |  |  |  |  |  | 25 |  |  | 22 |  |  |  |  |  |  |  |  |  |  | 2 |  |  | 4 |  |  |
Prior service cost (credit) |  |  |  |  |  |  | 1 |  |  | — |  |  |  |  |  |  |  |  |  |  | (13) |  |  | (14) |  |  |
Settlement loss |  |  |  |  |  |  | 1 |  |  | — |  |  |  |  |  |  |  |  |  |  | — |  |  | — |  |  |
Net periodic cost (credit) |  |  |  |  |  |  | $ | 4 |  |  | $ | 7 |  |  |  |  |  |  |  |  |  |  | $ | (28) |  |  | $ | (23) |  |  |
Consumers |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net periodic cost (credit) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Service cost |  |  |  |  |  |  | $ | 13 |  |  | $ | 12 |  |  |  |  |  |  |  |  |  |  | $ | 4 |  |  | $ | 4 |  |  |
Interest cost |  |  |  |  |  |  | 14 |  |  | 20 |  |  |  |  |  |  |  |  |  |  | 6 |  |  | 8 |  |  |
Expected return on plan assets |  |  |  |  |  |  | (49) |  |  | (45) |  |  |  |  |  |  |  |  |  |  | (25) |  |  | (23) |  |  |
Amortization of: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net loss |  |  |  |  |  |  | 25 |  |  | 21 |  |  |  |  |  |  |  |  |  |  | 2 |  |  | 4 |  |  |
Prior service cost (credit) |  |  |  |  |  |  | 1 |  |  | — |  |  |  |  |  |  |  |  |  |  | (13) |  |  | (14) |  |  |
Settlement loss |  |  |  |  |  |  | 1 |  |  | — |  |  |  |  |  |  |  |  |  |  | — |  |  | — |  |  |
Net periodic cost (credit) |  |  |  |  |  |  | $ | 5 |  |  | $ | 8 |  |  |  |  |  |  |  |  |  |  | $ | (26) |  |  | $ | (21) |  |  |

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