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Contingencies and Commitments (Tables) | 9 Months Ended
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Sep. 30, 2025
Site Contingency [Line Items] |
Schedule of Remediation and Other Response Activity Costs by Year | CMS Energy expects to pay the following amounts for long-term leachate disposal and operating and maintenance costs during the remainder of 2025 and in each of the next five years:
In Millions
| 2025 | 2026 | 2027 | 2028 | 2029 | 2030
Long-term leachate disposal and operating and maintenance costs |  | $ | 1 |  |  | $ | 4 |  |  | $ | 4 |  |  | $ | 4 |  |  | $ | 4 |  |  | $ | 4 |
Summary of Guarantees | Presented in the following table are CMS Energy’s and Consumers’ guarantees at September 30, 2025:
In Millions
Guarantee Description | Issue Date | Expiration Date | Maximum Obligation | Carrying Amount
CMS Energy, including Consumers |  |  |  |  |  |
Indemnity obligations from sale of membership interests in VIEs 1 | various | various |  | $ | 229 |  |  | $ | — |
Indemnity obligations from stock and asset sale agreements 2 | various | indefinite |  | 152 |  |  | — |
Guarantee 3 | 2011 | indefinite |  | 30 |  |  | — |
Consumers |  |  |  |  |  |
Guarantee 3 | 2011 | indefinite |  | $ | 30 |  |  | $ | — |
1 These obligations arose from the sale of membership interests in Aviator Wind, Newport Solar Holdings, and NWO Holdco to tax equity investors. NorthStar Clean Energy provided certain indemnity obligations that protect the tax equity investors against losses incurred as a result of breaches of representations and warranties under the associated limited liability company agreements. These obligations are generally capped at an amount equal to the tax equity investor’s capital contributions plus a specified return, less any distributions and tax benefits it receives, in connection with its membership interest. For any indemnity obligations related to Aviator Wind, NorthStar Clean Energy would recover 49 percent of any amounts paid to the tax equity investor from the other owner of Aviator Wind Equity Holdings. Additionally, Aviator Wind holds insurance coverage that would partially protect against losses incurred as a result of certain failures to qualify for production tax credits. For further details on NorthStar Clean Energy’s ownership interest in Aviator Wind, Newport Solar Holdings, and NWO Holdco, see Note 11, Variable Interest Entities. 2 These obligations arose from stock and asset sale agreements under which CMS Energy or a subsidiary of CMS Energy indemnified the purchaser for losses resulting from various matters, including claims related to taxes. The maximum obligation amount is mostly related to an Equatorial Guinea tax claim. 3 This obligation comprises a guarantee provided by Consumers to the U.S. Department of Energy in connection with a settlement agreement regarding damages resulting from the department’s failure to accept spent nuclear fuel from nuclear power plants formerly owned by Consumers.
Consumers Energy Company |
Site Contingency [Line Items] |
Schedule of Remediation and Other Response Activity Costs by Year | Consumers expects to pay the following amounts for remediation and other response activity costs during the remainder of 2025 and in each of the next five years:
In Millions
| 2025 | 2026 | 2027 | 2028 | 2029 | 2030
Remediation and other response activity costs |  | $ | — |  |  | $ | 3 |  |  | $ | 8 |  |  | $ | 25 |  |  | $ | 11 |  |  | $ | 3 |
Summary of Guarantees | Presented in the following table are CMS Energy’s and Consumers’ guarantees at September 30, 2025:
In Millions
Guarantee Description | Issue Date | Expiration Date | Maximum Obligation | Carrying Amount
CMS Energy, including Consumers |  |  |  |  |  |
Indemnity obligations from sale of membership interests in VIEs 1 | various | various |  | $ | 229 |  |  | $ | — |
Indemnity obligations from stock and asset sale agreements 2 | various | indefinite |  | 152 |  |  | — |
Guarantee 3 | 2011 | indefinite |  | 30 |  |  | — |
Consumers |  |  |  |  |  |
Guarantee 3 | 2011 | indefinite |  | $ | 30 |  |  | $ | — |
1 These obligations arose from the sale of membership interests in Aviator Wind, Newport Solar Holdings, and NWO Holdco to tax equity investors. NorthStar Clean Energy provided certain indemnity obligations that protect the tax equity investors against losses incurred as a result of breaches of representations and warranties under the associated limited liability company agreements. These obligations are generally capped at an amount equal to the tax equity investor’s capital contributions plus a specified return, less any distributions and tax benefits it receives, in connection with its membership interest. For any indemnity obligations related to Aviator Wind, NorthStar Clean Energy would recover 49 percent of any amounts paid to the tax equity investor from the other owner of Aviator Wind Equity Holdings. Additionally, Aviator Wind holds insurance coverage that would partially protect against losses incurred as a result of certain failures to qualify for production tax credits. For further details on NorthStar Clean Energy’s ownership interest in Aviator Wind, Newport Solar Holdings, and NWO Holdco, see Note 11, Variable Interest Entities. 2 These obligations arose from stock and asset sale agreements under which CMS Energy or a subsidiary of CMS Energy indemnified the purchaser for losses resulting from various matters, including claims related to taxes. The maximum obligation amount is mostly related to an Equatorial Guinea tax claim. 3 This obligation comprises a guarantee provided by Consumers to the U.S. Department of Energy in connection with a settlement agreement regarding damages resulting from the department’s failure to accept spent nuclear fuel from nuclear power plants formerly owned by Consumers.

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