Commitments and Contingencies	6 Months Ended
Jun. 30, 2025
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES Environmental DTE Electric Air — DTE Electric is subject to the EPA ozone and fine particulate transport and acid rain regulations that limit power plant emissions of SO2 and NOX. The EPA and the state of Michigan have also issued emission reduction regulations relating to ozone, fine particulate, regional haze, mercury, and other air pollution. These rules have led to controls on fossil-fueled power plants to reduce SO2, NOX, mercury, and other emissions. Additional rule making may occur over the next few years which could require additional controls for SO2, NOX, and other hazardous air pollutants. In March 2024, the EPA finalized the NAAQS for fine particulate matter, particles of pollution with diameters generally 2.5 micrometers and smaller (PM2.5). It is likely that areas of Michigan in which DTE Electric operates will be designated as non-attainment in the future, and the state will be required to develop a SIP for such areas. However, the EPA has announced its intention to review the standard. No impact is expected in the near term, and any long-term financial impacts cannot be assessed at this time. In April 2024, the EPA finalized new rules to address emissions of GHGs from existing, new, modified, or reconstructed sources in the power sector. In June 2025, the EPA proposed a rule to repeal the GHG standards along with an alternative to eliminate various portions of the standards. The EPA intends to finalize the repeal or alternative by the end of 2025. The financial impacts of the new rules are still being assessed. Pending or future legislation or other regulatory actions could have a material impact on DTE Electric's operations and financial position and the rates charged to its customers. Potential impacts include expenditures for environmental equipment beyond what is currently planned, financing costs related to additional capital expenditures, the purchase of emission credits from market sources, higher costs of purchased power, and the retirement of facilities where control equipment is not economical. DTE Electric would seek to recover these incremental costs through increased rates charged to its utility customers, as authorized by the MPSC. To comply with air pollution requirements, DTE Electric has spent approximately $2.4 billion. DTE Electric does not anticipate additional capital expenditures for air pollution requirements, subject to the results of future rulemakings. Water — In response to EPA regulations and in accordance with the Clean Water Act section 316(b), DTE Electric was required to examine alternatives for reducing the environmental impacts of the cooling water intake structures at several of its facilities. A final rule became effective in October 2014, which required studies to be completed and submitted as part of the NPDES permit application process to determine the type of technology needed to reduce impacts to fish. DTE Electric has completed the required studies and submitted reports for most of its generation plants, and a final study is in-process for Monroe power plant. Final compliance for the installation of any required technology to reduce the impacts of water intake structures will be determined by the state on a case by case, site specific basis. As part of the Monroe power plant NPDES permit, EGLE has added an option to evaluate the thermal discharge of the facility as it relates to Clean Water Act section 316(a) regulations in order to establish an appropriate temperature discharge limit. DTE Electric has submitted to EGLE a biological demonstration study plan to evaluate the thermal discharge impacts to an aquatic community. Approval of the plan by EGLE occurred in May 2025. Field sampling had commenced, and data will be processed and compiled into a comprehensive report. At the present time, DTE Electric cannot predict the outcome of this evaluation or financial impact. Contaminated and Other Sites — Prior to the construction of major interstate natural gas pipelines, gas for heating and other uses was manufactured locally from processes involving coal, coke, or oil. The facilities, which produced gas, have been designated as MGP sites. DTE Electric conducted remedial investigations at contaminated sites, including three former MGP sites. The investigations at the former MGP sites have revealed contamination related to the by-products of gas manufacturing. Cleanup of one of the MGP sites is complete, and that site is closed. DTE Electric has also completed partial closure of one additional site. Cleanup activities associated with the remaining sites will continue over the next several years. In addition to the MGP sites, DTE Electric is also in the process of cleaning up other contaminated sites, including the area surrounding an ash landfill, electrical distribution substations, electric generating power plants, and underground and above ground storage tank locations. The findings of these investigations indicated that the estimated cost to remediate these sites is expected to be incurred over the next several years. At June 30, 2025 and December 31, 2024, DTE Electric had $10 million accrued for remediation. These costs are not discounted to their present value. Any change in assumptions, such as remediation techniques, nature and extent of contamination, and regulatory requirements, could impact the estimate of remedial action costs for the sites and affect DTE Electric’s financial position and cash flows. DTE Electric believes the likelihood of a material change to the accrued amount is remote based on current knowledge of the conditions at each site. Coal Combustion Residuals and Effluent Limitations Guidelines — A final EPA rule for the disposal of coal combustion residuals, commonly known as coal ash, became effective in October 2015 and has continued to be updated in subsequent years. The rule is based on the continued listing of coal ash as a non-hazardous waste and relies on various self-implementation design and performance standards. DTE Electric currently owns and operates multiple coal ash storage facilities to manage coal ash from coal-fired power plants that are subject to federal, state, and local CCR and solid waste regulations. At certain facilities, the rule required ongoing sampling and testing of monitoring wells, compliance with groundwater standards, and closure. On May 8, 2024, the EPA finalized a new rule to regulate legacy CCR surface impoundments and CCR management units. The rule expands the reach of the CCR rule to inactive electric generation sites and previously unregulated CCR at any active facility. The rule also extends the dewatering and stabilization criteria of the closure in place performance standards to existing CCR landfills. DTE Electric has no legacy CCR surface impoundments, but has other regulated CCR units and is evaluating sites for CCR management units. DTE Electric is in the process of evaluating the final 2024 rule, which may have significant financial impacts depending on the site-specific characteristics of the units that are regulated by the new rule. Long-term financial impacts cannot be clearly defined at this time and likely will not be clearly defined until the regulated units are identified. Challenges to the rule have been filed, and DTE Electric will continue to monitor for regulatory developments. Recently, at the request of the EPA, the D.C. Circuit Court has held the pending litigation in abeyance to accommodate the EPA's reconsideration of the rule. The EPA recently announced their desire to revise the CCR regulations, but at this time the effective date and extent of any revisions are unknown. The preliminary cost estimate to comply with the revised rule is approximately $296 million as of June 30, 2025, and is recorded to Asset retirement obligations. The estimate will be updated as necessary when site-specific details are more fully known. These costs are expected to be recoverable under the regulatory construct as part of removal costs. At the state level, legislation was signed in December 2018 and provides for further regulation of the CCR program in Michigan. Additionally, the statutory revision provides the basis of a CCR program that EGLE has submitted to the EPA for approval to fully regulate the CCR program in Michigan in lieu of a federal permit program. The EPA is currently working with EGLE in reviewing the submitted state program, and DTE Electric will work with EGLE to implement the state program that may be approved in the future. The EPA updated and revised the ELG in 2015, 2020, and 2024. In each revision, EPA has re-established technology-based standards applicable to wastewaters created at facilities with an electrical generating unit. In each revision, the EPA also established new applicability dates. The Reconsideration Rule, finalized in 2020, provided additional opportunities by finalizing a group of compliance subcategories that provided cessation of coal as a compliance option. Additionally, the 2020 Reconsideration Rule established the Voluntary Incentives Program (VIP) for FGD wastewater compliance only. If a facility applies for the VIP, they must meet more stringent standards, but are allowed an extended time period to meet the compliance requirements by December 1, 2028. The Reconsideration Rule provided these new opportunities for DTE Electric to evaluate existing ELG compliance strategies and make any necessary adjustments to ensure full compliance with the ELGs in a cost-effective manner. Compliance schedules for individual facilities and individual waste streams are determined through issuance of new NPDES permits by the state of Michigan. The state of Michigan issued an NPDES permit for the Belle River power plant establishing compliance deadlines based on the 2020 Reconsideration Rule. On October 11, 2021, DTE Electric submitted a Notice of Planned Participation (NOPP) to the state of Michigan that formally announced the intent to pursue compliance subcategories as ELG compliance options: the cessation of coal at the Belle River power plant no later than December 31, 2028 and the VIP for FGD wastewater at Monroe power plant by December 31, 2028. The EPA also finalized Supplemental ELG Rules on May 9, 2024. This updated the regulations from the 2020 Reconsideration Rule for FGD wastewater, bottom ash transport water (BATW), combustion residual leachate (CRL), and legacy wastewater (LWW). The supplemental rule established new technology-based effluent limitations guidelines and standards applicable to FGD wastewater, BATW, CRL, and LWW. The applicability date for BATW is as soon as possible beginning July 8, 2024 and no later than December 31, 2029. FGD wastewater retrofits must be completed as soon as possible, beginning July 8, 2024 and no later than December, 31 2029 or December 31, 2028 if a permittee is pursuing the VIP subcategory for FGD wastewater. The Cessation of Coal compliance subcategory and VIP from the 2020 Reconsideration Rule were maintained in the 2024 Supplemental Rule and continue to be a fundamental component of DTE Electric's ELG compliance strategy. The EPA recently announced that they will be reviewing and possibly revising the 2024 Supplemental ELG Rule. At this time, DTE Electric cannot predict effective dates for any revisions or their financial impacts. DTE Electric's compliance strategy includes the conversion of the two generating units at the Belle River power plant to a natural gas peaking resource in 2025-2026, which was included in the NOPP filed in 2021. DTE Electric also submitted a new NOPP to apply for the cessation of coal compliance subcategory for generating units 3 and 4 at the Monroe power plant. DTE Electric plans to retire Monroe's generating units 1 and 2 in 2032. DTE Electric continues to evaluate compliance strategies, technologies and system designs to achieve compliance with the EPA rules at the Monroe power plant in accordance with the VIP subcategory for FGD and new discharge requirements for BATW. Additionally, DTE Electric is evaluating compliance strategies and options to address new requirement and deadlines for other wastewater streams in the 2024 Supplemental Rule at both Belle River Power Plant and Sibley Quarry. DTE Electric currently estimates the impact of the CCR and ELG rules to be $511 million of capital expenditures through 2029. This estimate may change in future periods as DTE Electric evaluates the CCR and ELG rules discussed above that have recently been finalized. DTE Gas Contaminated and Other Sites — DTE Gas owns or previously owned 14 former MGP sites. Investigations have revealed contamination related to the by-products of gas manufacturing at each site. Cleanup of eight MGP sites is complete and those sites are closed. DTE Gas has also completed partial closure of five additional sites. Cleanup activities associated with the remaining sites will continue over the next several years. The MPSC has established a cost deferral and rate recovery mechanism for investigation and remediation costs incurred at former MGP sites. In addition to the MGP sites, DTE Gas is also in the process of cleaning up other contaminated sites, including gate stations, gas pipeline releases, and underground storage tank locations. As of June 30, 2025 and December 31, 2024, DTE Gas had $25 million and $26 million, respectively, accrued for remediation. These costs are not discounted to their present value. Any change in assumptions, such as remediation techniques, nature and extent of contamination, and regulatory requirements, could impact the estimate of remedial action costs for the sites and affect DTE Gas' financial position and cash flows. DTE Gas anticipates the cost amortization methodology approved by the MPSC, which allows for amortization of the MGP costs over a ten-year period beginning with the year subsequent to the year the MGP costs were incurred, will prevent the associated investigation and remediation costs from having a material adverse impact on DTE Gas' results of operations. Air — In March 2023, the EPA published the Good Neighbor Rule, which includes provisions for compressor engines operated for the transportation of natural gas. In June 2024, the United States Supreme Court issued an opinion granting emergency applications to stay the Good Neighbor Rule. The stay will remain in effect during other litigation. The status of the rule remains uncertain as litigation is ongoing. At this time, DTE Gas does not expect a significant financial impact. As noted above for DTE Electric, the EPA finalized the NAAQS for fine particulate matter in March 2024. It is likely that areas of Michigan in which DTE Gas operates will be designated as non-attainment in the future and the state will be required to develop a SIP for such areas. However, the EPA has announced its intention to review the standard. No impact is expected in the near term, and any long-term financial impacts cannot be assessed at this time. Non-utility DTE Energy's non-utility businesses are subject to a number of environmental laws and regulations dealing with the protection of the environment from various pollutants. In March 2019, the EPA issued an FOV to EES Coke Battery, LLC ("EES Coke"), the Michigan coke battery facility that is a wholly-owned subsidiary of DTE Energy, alleging that the 2008 and 2014 permits issued by EGLE did not comply with the Clean Air Act. In September 2020, the EPA issued another FOV alleging EES Coke's 2018 and 2019 SO2 emissions exceeded projections and hence violated non-attainment new source review permitting requirements. EES Coke evaluated the EPA's alleged violations and believes that the permits approved by EGLE complied with the Clean Air Act. EES Coke responded to the EPA's September 2020 allegations demonstrating its actual emissions are compliant with non-attainment new source review requirements. On June 1, 2022, the U.S. Department of Justice ("DOJ"), on behalf of the EPA, filed a complaint against EES Coke in the U.S. District Court for the Eastern District of Michigan alleging that EES Coke failed to comply with non-attainment new source review requirements under the Clean Air Act when it applied for the 2014 permit. In November 2022, the Sierra Club and City of River Rouge were granted intervention. On May 20, 2024, the court granted a motion allowing the DOJ to amend their complaint to add EES Coke's parent entities, including DTE Energy, as defendants. The parent entities were added in an attempt to share in any potential liability; there are no additional claims alleged. Discovery has concluded and trial is set for September 2025. At the present time, DTE Energy cannot predict the outcome or financial impact of this matter. Other In 2010, the EPA finalized a new one-hour SO2 ambient air quality standard that requires states to submit plans and associated timelines for non-attainment areas that demonstrate attainment with the new SO2 standard in phases. Phase 1 addresses non-attainment areas designated based on ambient monitoring data. Phase 2 addresses non-attainment areas with large sources of SO2 and modeled concentrations exceeding the National Ambient Air Quality Standards for SO2. Phase 3 addresses smaller sources of SO2 with modeled or monitored exceedances of the new SO2 standard. Michigan's Phase 1 non-attainment area included DTE Energy facilities. However, the EPA published a Federal Implementation Plan (FIP) for the area in June 2022 that did not impact any DTE Energy facilities. It is also not expected that Phase 3 will have any impact on DTE Energy. Michigan's Phase 2 non-attainment area includes DTE Electric facilities in St. Clair County. The EPA approved a clean data determination request submitted by EGLE. This determination suspends certain planning requirements and sanctions for the non-attainment area for as long as the area continues to attain the 2010 SO2 air quality standards, but this does not automatically redesignate the area to attainment. Until the area is officially redesignated as attainment, DTE Energy is unable to determine the impacts. REF Guarantees DTE Energy provided certain guarantees and indemnities in conjunction with the sales of interests in or lease of its previously operated REF facilities. The guarantees cover potential commercial, environmental, and tax-related obligations that will survive until 90 days after expiration of all applicable statutes of limitations. DTE Energy estimates that its maximum potential liability under these guarantees at June 30, 2025 was $201 million. Payments under these guarantees are considered remote. Other Guarantees In certain limited circumstances, the Registrants enter into contractual guarantees. The Registrants may guarantee another entity’s obligation in the event it fails to perform and may provide guarantees in certain indemnification agreements. The Registrants may also provide indirect guarantees for the indebtedness of others. DTE Energy’s guarantees are not individually material with maximum potential payments totaling $69 million at June 30, 2025. Payments under these guarantees are considered remote. The Registrants are periodically required to obtain performance surety bonds in support of obligations to various governmental entities and other companies in connection with its operations. As of June 30, 2025, DTE Energy had $406 million of performance bonds outstanding, including $231 million for DTE Electric. Performance bonds are not individually material, except for $130 million of bonds supporting Energy Trading operations. These bonds are meant to provide counterparties with additional assurance that Energy Trading will meet its contractual obligations for various commercial transactions. The terms of the bonds align with those of the underlying Energy Trading contracts and are estimated to be outstanding approximately 1 to 3 years. In the event that any performance bonds are called for nonperformance, the Registrants would be obligated to reimburse the issuer of the performance bond. The Registrants are released from the performance bonds as the contractual performance is completed and does not believe that a material amount of any currently outstanding performance bonds will be called. Labor Contracts There are several bargaining units for DTE Energy subsidiaries' approximately 4,700 represented employees, including DTE Electric's approximately 2,500 represented employees. This represents 50% and 58% of DTE Energy's and DTE Electric's total employees, respectively. Of these represented employees, approximately 3% have contracts expiring within one year for DTE Energy. Less than 1% of the represented employees have contracts expiring within one year for DTE Electric. Purchase Commitments Utility capital expenditures and expenditures for non-utility businesses will be approximately $4.9 billion and $3.7 billion in 2025 for DTE Energy and DTE Electric, respectively. The Registrants have made certain commitments in connection with the estimated 2025 annual capital expenditures. Ludington Plant Contract Dispute DTE Electric and Consumers Energy Company ("Consumers"), joint owners of the Ludington Hydroelectric Pumped Storage plant ("Ludington"), entered into a 2010 engineering, procurement, and construction agreement with Toshiba International Corporation ("TIC"), under which TIC contracted to perform a major overhaul and upgrade of Ludington. TIC later assigned the contract and all its obligations to Toshiba America Energy Systems ("TAES"). TAES' work under the contract was incomplete, defective, and non-conforming. DTE Electric and Consumers repeatedly documented TAES' failures to perform under the contract and demanded that TAES provide a comprehensive plan to resolve those matters, including adherence to its warranty commitments and other contractual obligations. DTE Electric and Consumers engaged in extensive efforts to resolve these issues with TAES, including a formal demand to TAES' parent, Toshiba Corporation ("Toshiba"), under a parent guaranty it provided. TAES did not provide a comprehensive plan or otherwise met its performance obligations. As a result of TAES' defaults, DTE Electric and Consumers terminated the contract. In order to enforce their rights under the contract and parent guaranty, and to pursue appropriate damages, DTE Electric and Consumers filed a complaint against TAES and Toshiba in the U.S. District Court for the Eastern District of Michigan in 2022. TAES and Toshiba filed a motion to dismiss the complaint, along with an answer and counterclaims seeking approximately $15 million in damages related to payments allegedly owed under the parties' contract. The motion to dismiss the complaint was denied. DTE Electric believes the outstanding counterclaims are without merit, but would be liable for 49% of the damages if approved. The parties are engaged in ongoing litigation pursuant to a court-ordered schedule. DTE Electric cannot predict the financial impact or outcome of this matter. In 2023, the MPSC approved a jointly-filed request by DTE Electric and Consumers for authority to defer as a regulatory asset the costs associated with repairing or replacing the defective work performed by TAES while the litigation with TAES and Toshiba moves forward. DTE Electric currently estimates its share of these repair and replacement costs ranges from $350 million to $400 million. Such costs will be offset by any potential litigation proceeds received from TAES or Toshiba. DTE Electric and Consumers will have the opportunity to seek recovery and ratemaking treatment for amounts recorded as a regulatory asset following resolution of the litigation, including amounts not recovered from TAES or Toshiba. Other Contingencies The Registrants are involved in certain other legal, regulatory, administrative, and environmental proceedings before various courts, arbitration panels, and governmental agencies concerning claims arising in the ordinary course of business. These proceedings include certain contract disputes, additional environmental reviews and investigations, audits, inquiries from various regulators, and pending judicial matters. The Registrants cannot predict the final disposition of such proceedings. The Registrants regularly review legal matters and record provisions for claims that they can estimate and are considered probable of loss. The resolution of these pending proceedings is not expected to have a material effect on the Registrants' Consolidated Financial Statements in the periods they are resolved. For a discussion of contingencies related to regulatory matters and derivatives, see Notes 5 and 8 to the Consolidated Financial Statements, "Regulatory Matters" and "Financial and Other Derivative Instruments," respectively.

Air — DTE Electric is subject to the EPA ozone and fine particulate transport and acid rain regulations that limit power plant emissions of SO2 and NOX. The EPA and the state of Michigan have also issued emission reduction regulations relating to ozone, fine particulate, regional haze, mercury, and other air pollution. These rules have led to controls on fossil-fueled power plants to reduce SO2, NOX, mercury, and other emissions. Additional rule making may occur over the next few years which could require additional controls for SO2, NOX, and other hazardous air pollutants.

In March 2024, the EPA finalized the NAAQS for fine particulate matter, particles of pollution with diameters generally 2.5 micrometers and smaller (PM2.5). It is likely that areas of Michigan in which DTE Electric operates will be designated as non-attainment in the future, and the state will be required to develop a SIP for such areas. However, the EPA has announced its intention to review the standard. No impact is expected in the near term, and any long-term financial impacts cannot be assessed at this time.

In April 2024, the EPA finalized new rules to address emissions of GHGs from existing, new, modified, or reconstructed sources in the power sector. In June 2025, the EPA proposed a rule to repeal the GHG standards along with an alternative to eliminate various portions of the standards. The EPA intends to finalize the repeal or alternative by the end of 2025. The financial impacts of the new rules are still being assessed.

Pending or future legislation or other regulatory actions could have a material impact on DTE Electric's operations and financial position and the rates charged to its customers. Potential impacts include expenditures for environmental equipment beyond what is currently planned, financing costs related to additional capital expenditures, the purchase of emission credits from market sources, higher costs of purchased power, and the retirement of facilities where control equipment is not economical. DTE Electric would seek to recover these incremental costs through increased rates charged to its utility customers, as authorized by the MPSC.

Water — In response to EPA regulations and in accordance with the Clean Water Act section 316(b), DTE Electric was required to examine alternatives for reducing the environmental impacts of the cooling water intake structures at several of its facilities. A final rule became effective in October 2014, which required studies to be completed and submitted as part of the NPDES permit application process to determine the type of technology needed to reduce impacts to fish. DTE Electric has completed the required studies and submitted reports for most of its generation plants, and a final study is in-process for Monroe power plant. Final compliance for the installation of any required technology to reduce the impacts of water intake structures will be determined by the state on a case by case, site specific basis.

As part of the Monroe power plant NPDES permit, EGLE has added an option to evaluate the thermal discharge of the facility as it relates to Clean Water Act section 316(a) regulations in order to establish an appropriate temperature discharge limit. DTE Electric has submitted to EGLE a biological demonstration study plan to evaluate the thermal discharge impacts to an aquatic community. Approval of the plan by EGLE occurred in May 2025. Field sampling had commenced, and data will be processed and compiled into a comprehensive report. At the present time, DTE Electric cannot predict the outcome of this evaluation or financial impact.

Contaminated and Other Sites — Prior to the construction of major interstate natural gas pipelines, gas for heating and other uses was manufactured locally from processes involving coal, coke, or oil. The facilities, which produced gas, have been designated as MGP sites. DTE Electric conducted remedial investigations at contaminated sites, including three former MGP sites. The investigations at the former MGP sites have revealed contamination related to the by-products of gas manufacturing. Cleanup of one of the MGP sites is complete, and that site is closed. DTE Electric has also completed partial closure of one additional site. Cleanup activities associated with the remaining sites will continue over the next several years. In addition to the MGP sites, DTE Electric is also in the process of cleaning up other contaminated sites, including the area surrounding an ash landfill, electrical distribution substations, electric generating power plants, and underground and above ground storage tank locations. The findings of these investigations indicated that the estimated cost to remediate these sites is expected to be incurred over the next several years. At June 30, 2025 and December 31, 2024, DTE Electric had $10 million accrued for remediation. These costs are not discounted to their present value. Any change in assumptions, such as remediation techniques, nature and extent of contamination, and regulatory requirements, could impact the estimate of remedial action costs for the sites and affect DTE Electric’s financial position and cash flows. DTE Electric believes the likelihood of a material change to the accrued amount is remote based on current knowledge of the conditions at each site.

Coal Combustion Residuals and Effluent Limitations Guidelines — A final EPA rule for the disposal of coal combustion residuals, commonly known as coal ash, became effective in October 2015 and has continued to be updated in subsequent years. The rule is based on the continued listing of coal ash as a non-hazardous waste and relies on various self-implementation design and performance standards. DTE Electric currently owns and operates multiple coal ash storage facilities to manage coal ash from coal-fired power plants that are subject to federal, state, and local CCR and solid waste regulations. At certain facilities, the rule required ongoing sampling and testing of monitoring wells, compliance with groundwater standards, and closure.

On May 8, 2024, the EPA finalized a new rule to regulate legacy CCR surface impoundments and CCR management units. The rule expands the reach of the CCR rule to inactive electric generation sites and previously unregulated CCR at any active facility. The rule also extends the dewatering and stabilization criteria of the closure in place performance standards to existing CCR landfills. DTE Electric has no legacy CCR surface impoundments, but has other regulated CCR units and is evaluating sites for CCR management units. DTE Electric is in the process of evaluating the final 2024 rule, which may have significant financial impacts depending on the site-specific characteristics of the units that are regulated by the new rule. Long-term financial impacts cannot be clearly defined at this time and likely will not be clearly defined until the regulated units are identified. Challenges to the rule have been filed, and DTE Electric will continue to monitor for regulatory developments. Recently, at the request of the EPA, the D.C. Circuit Court has held the pending litigation in abeyance to accommodate the EPA's reconsideration of the rule. The EPA recently announced their desire to revise the CCR regulations, but at this time the effective date and extent of any revisions are unknown. The preliminary cost estimate to comply with the revised rule is approximately $296 million as of June 30, 2025, and is recorded to Asset retirement obligations. The estimate will be updated as necessary when site-specific details are more fully known. These costs are expected to be recoverable under the regulatory construct as part of removal costs.

At the state level, legislation was signed in December 2018 and provides for further regulation of the CCR program in Michigan. Additionally, the statutory revision provides the basis of a CCR program that EGLE has submitted to the EPA for approval to fully regulate the CCR program in Michigan in lieu of a federal permit program. The EPA is currently working with EGLE in reviewing the submitted state program, and DTE Electric will work with EGLE to implement the state program that may be approved in the future.

The Reconsideration Rule, finalized in 2020, provided additional opportunities by finalizing a group of compliance subcategories that provided cessation of coal as a compliance option. Additionally, the 2020 Reconsideration Rule established the Voluntary Incentives Program (VIP) for FGD wastewater compliance only. If a facility applies for the VIP, they must meet more stringent standards, but are allowed an extended time period to meet the compliance requirements by December 1, 2028. The Reconsideration Rule provided these new opportunities for DTE Electric to evaluate existing ELG compliance strategies and make any necessary adjustments to ensure full compliance with the ELGs in a cost-effective manner.

Compliance schedules for individual facilities and individual waste streams are determined through issuance of new NPDES permits by the state of Michigan. The state of Michigan issued an NPDES permit for the Belle River power plant establishing compliance deadlines based on the 2020 Reconsideration Rule. On October 11, 2021, DTE Electric submitted a Notice of Planned Participation (NOPP) to the state of Michigan that formally announced the intent to pursue compliance subcategories as ELG compliance options: the cessation of coal at the Belle River power plant no later than December 31, 2028 and the VIP for FGD wastewater at Monroe power plant by December 31, 2028.

The EPA also finalized Supplemental ELG Rules on May 9, 2024. This updated the regulations from the 2020 Reconsideration Rule for FGD wastewater, bottom ash transport water (BATW), combustion residual leachate (CRL), and legacy wastewater (LWW). The supplemental rule established new technology-based effluent limitations guidelines and standards applicable to FGD wastewater, BATW, CRL, and LWW. The applicability date for BATW is as soon as possible beginning July 8, 2024 and no later than December 31, 2029. FGD wastewater retrofits must be completed as soon as possible, beginning July 8, 2024 and no later than December, 31 2029 or December 31, 2028 if a permittee is pursuing the VIP subcategory for FGD wastewater. The Cessation of Coal compliance subcategory and VIP from the 2020 Reconsideration Rule were maintained in the 2024 Supplemental Rule and continue to be a fundamental component of DTE Electric's ELG compliance strategy. The EPA recently announced that they will be reviewing and possibly revising the 2024 Supplemental ELG Rule. At this time, DTE Electric cannot predict effective dates for any revisions or their financial impacts.

DTE Electric's compliance strategy includes the conversion of the two generating units at the Belle River power plant to a natural gas peaking resource in 2025-2026, which was included in the NOPP filed in 2021. DTE Electric also submitted a new NOPP to apply for the cessation of coal compliance subcategory for generating units 3 and 4 at the Monroe power plant. DTE Electric plans to retire Monroe's generating units 1 and 2 in 2032.

DTE Electric continues to evaluate compliance strategies, technologies and system designs to achieve compliance with the EPA rules at the Monroe power plant in accordance with the VIP subcategory for FGD and new discharge requirements for BATW. Additionally, DTE Electric is evaluating compliance strategies and options to address new requirement and deadlines for other wastewater streams in the 2024 Supplemental Rule at both Belle River Power Plant and Sibley Quarry.

Contaminated and Other Sites — DTE Gas owns or previously owned 14 former MGP sites. Investigations have revealed contamination related to the by-products of gas manufacturing at each site. Cleanup of eight MGP sites is complete and those sites are closed. DTE Gas has also completed partial closure of five additional sites. Cleanup activities associated with the remaining sites will continue over the next several years. The MPSC has established a cost deferral and rate recovery mechanism for investigation and remediation costs incurred at former MGP sites. In addition to the MGP sites, DTE Gas is also in the process of cleaning up other contaminated sites, including gate stations, gas pipeline releases, and underground storage tank locations. As of June 30, 2025 and December 31, 2024, DTE Gas had $25 million and $26 million, respectively, accrued for remediation. These costs are not discounted to their present value. Any change in assumptions, such as remediation techniques, nature and extent of contamination, and regulatory requirements, could impact the estimate of remedial action costs for the sites and affect DTE Gas' financial position and cash flows. DTE Gas anticipates the cost amortization methodology approved by the MPSC, which allows for amortization of the MGP costs over a ten-year period beginning with the year subsequent to the year the MGP costs were incurred, will prevent the associated investigation and remediation costs from having a material adverse impact on DTE Gas' results of operations.

Air — In March 2023, the EPA published the Good Neighbor Rule, which includes provisions for compressor engines operated for the transportation of natural gas. In June 2024, the United States Supreme Court issued an opinion granting emergency applications to stay the Good Neighbor Rule. The stay will remain in effect during other litigation. The status of the rule remains uncertain as litigation is ongoing. At this time, DTE Gas does not expect a significant financial impact.

As noted above for DTE Electric, the EPA finalized the NAAQS for fine particulate matter in March 2024. It is likely that areas of Michigan in which DTE Gas operates will be designated as non-attainment in the future and the state will be required to develop a SIP for such areas. However, the EPA has announced its intention to review the standard. No impact is expected in the near term, and any long-term financial impacts cannot be assessed at this time.

In March 2019, the EPA issued an FOV to EES Coke Battery, LLC ("EES Coke"), the Michigan coke battery facility that is a wholly-owned subsidiary of DTE Energy, alleging that the 2008 and 2014 permits issued by EGLE did not comply with the Clean Air Act. In September 2020, the EPA issued another FOV alleging EES Coke's 2018 and 2019 SO2 emissions exceeded projections and hence violated non-attainment new source review permitting requirements. EES Coke evaluated the EPA's alleged violations and believes that the permits approved by EGLE complied with the Clean Air Act. EES Coke responded to the EPA's September 2020 allegations demonstrating its actual emissions are compliant with non-attainment new source review requirements. On June 1, 2022, the U.S. Department of Justice ("DOJ"), on behalf of the EPA, filed a complaint against EES Coke in the U.S. District Court for the Eastern District of Michigan alleging that EES Coke failed to comply with non-attainment new source review requirements under the Clean Air Act when it applied for the 2014 permit. In November 2022, the Sierra Club and City of River Rouge were granted intervention. On May 20, 2024, the court granted a motion allowing the DOJ to amend their complaint to add EES Coke's parent entities, including DTE Energy, as defendants. The parent entities were added in an attempt to share in any potential liability; there are no additional claims alleged. Discovery has concluded and trial is set for September 2025. At the present time, DTE Energy cannot predict the outcome or financial impact of this matter.

In 2010, the EPA finalized a new one-hour SO2 ambient air quality standard that requires states to submit plans and associated timelines for non-attainment areas that demonstrate attainment with the new SO2 standard in phases. Phase 1 addresses non-attainment areas designated based on ambient monitoring data. Phase 2 addresses non-attainment areas with large sources of SO2 and modeled concentrations exceeding the National Ambient Air Quality Standards for SO2. Phase 3 addresses smaller sources of SO2 with modeled or monitored exceedances of the new SO2 standard.

Michigan's Phase 2 non-attainment area includes DTE Electric facilities in St. Clair County. The EPA approved a clean data determination request submitted by EGLE. This determination suspends certain planning requirements and sanctions for the non-attainment area for as long as the area continues to attain the 2010 SO2 air quality standards, but this does not automatically redesignate the area to attainment. Until the area is officially redesignated as attainment, DTE Energy is unable to determine the impacts.

DTE Energy provided certain guarantees and indemnities in conjunction with the sales of interests in or lease of its previously operated REF facilities. The guarantees cover potential commercial, environmental, and tax-related obligations that will survive until 90 days after expiration of all applicable statutes of limitations. DTE Energy estimates that its maximum potential liability under these guarantees at June 30, 2025 was $201 million. Payments under these guarantees are considered remote.

In certain limited circumstances, the Registrants enter into contractual guarantees. The Registrants may guarantee another entity’s obligation in the event it fails to perform and may provide guarantees in certain indemnification agreements. The Registrants may also provide indirect guarantees for the indebtedness of others. DTE Energy’s guarantees are not individually material with maximum potential payments totaling $69 million at June 30, 2025. Payments under these guarantees are considered remote.

The Registrants are periodically required to obtain performance surety bonds in support of obligations to various governmental entities and other companies in connection with its operations. As of June 30, 2025, DTE Energy had $406 million of performance bonds outstanding, including $231 million for DTE Electric. Performance bonds are not individually material, except for $130 million of bonds supporting Energy Trading operations. These bonds are meant to provide counterparties with additional assurance that Energy Trading will meet its contractual obligations for various commercial transactions. The terms of the bonds align with those of the underlying Energy Trading contracts and are estimated to be outstanding approximately 1 to 3 years. In the event that any performance bonds are called for nonperformance, the Registrants would be obligated to reimburse the issuer of the performance bond. The Registrants are released from the performance bonds as the contractual performance is completed and does not believe that a material amount of any currently outstanding performance bonds will be called.

There are several bargaining units for DTE Energy subsidiaries' approximately 4,700 represented employees, including DTE Electric's approximately 2,500 represented employees. This represents 50% and 58% of DTE Energy's and DTE Electric's total employees, respectively. Of these represented employees, approximately 3% have contracts expiring within one year for DTE Energy. Less than 1% of the represented employees have contracts expiring within one year for DTE Electric.

DTE Electric and Consumers Energy Company ("Consumers"), joint owners of the Ludington Hydroelectric Pumped Storage plant ("Ludington"), entered into a 2010 engineering, procurement, and construction agreement with Toshiba International Corporation ("TIC"), under which TIC contracted to perform a major overhaul and upgrade of Ludington. TIC later assigned the contract and all its obligations to Toshiba America Energy Systems ("TAES"). TAES' work under the contract was incomplete, defective, and non-conforming. DTE Electric and Consumers repeatedly documented TAES' failures to perform under the contract and demanded that TAES provide a comprehensive plan to resolve those matters, including adherence to its warranty commitments and other contractual obligations. DTE Electric and Consumers engaged in extensive efforts to resolve these issues with TAES, including a formal demand to TAES' parent, Toshiba Corporation ("Toshiba"), under a parent guaranty it provided. TAES did not provide a comprehensive plan or otherwise met its performance obligations. As a result of TAES' defaults, DTE Electric and Consumers terminated the contract.

In order to enforce their rights under the contract and parent guaranty, and to pursue appropriate damages, DTE Electric and Consumers filed a complaint against TAES and Toshiba in the U.S. District Court for the Eastern District of Michigan in 2022. TAES and Toshiba filed a motion to dismiss the complaint, along with an answer and counterclaims seeking approximately $15 million in damages related to payments allegedly owed under the parties' contract. The motion to dismiss the complaint was denied. DTE Electric believes the outstanding counterclaims are without merit, but would be liable for 49% of the damages if approved. The parties are engaged in ongoing litigation pursuant to a court-ordered schedule. DTE Electric cannot predict the financial impact or outcome of this matter.

In 2023, the MPSC approved a jointly-filed request by DTE Electric and Consumers for authority to defer as a regulatory asset the costs associated with repairing or replacing the defective work performed by TAES while the litigation with TAES and Toshiba moves forward. DTE Electric currently estimates its share of these repair and replacement costs ranges from $350 million to $400 million. Such costs will be offset by any potential litigation proceeds received from TAES or Toshiba. DTE Electric and Consumers will have the opportunity to seek recovery and ratemaking treatment for amounts recorded as a regulatory asset following resolution of the litigation, including amounts not recovered from TAES or Toshiba.

The Registrants are involved in certain other legal, regulatory, administrative, and environmental proceedings before various courts, arbitration panels, and governmental agencies concerning claims arising in the ordinary course of business. These proceedings include certain contract disputes, additional environmental reviews and investigations, audits, inquiries from various regulators, and pending judicial matters. The Registrants cannot predict the final disposition of such proceedings. The Registrants regularly review legal matters and record provisions for claims that they can estimate and are considered probable of loss. The resolution of these pending proceedings is not expected to have a material effect on the Registrants' Consolidated Financial Statements in the periods they are resolved.