Commitment and Contingencies	3 Months Ended
Mar. 31, 2026
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES LEGAL We are involved in claims, legal proceedings, investigations, and regulatory matters arising in the normal course of business. We regularly analyze relevant information and, as necessary, estimate and record accrued liabilities for legal, regulatory enforcement and other matters in which a loss or range of loss is probable of occurring and can be reasonably estimated. We believe the effect on our consolidated operating results, financial position and cash flows, if any, for the disposition of all matters pending as of March 31, 2026, other than those discussed below, will not be material. LITIGATION–On November 7, 2019, McKenzie Electric Cooperative, Inc. (McKenzie), a Class C Member of Basin Electric and a member of Class A Member Upper Missouri G&T Electric Cooperative, Inc. (Upper Missouri), filed a lawsuit in North Dakota State Court against both Basin Electric and Upper Missouri. The complaint brought multiple claims against Basin Electric, some of which have since been dismissed. McKenzie’s remaining claims against Basin Electric are: (1) breach of the wholesale power contract (WPC) between Basin Electric and Upper Missouri (either as an alleged three-tier contract among Basin Electric, Upper Missouri and McKenzie, or with McKenzie being a third-party beneficiary to the WPC) by including losses associated with Dakota Gas in rates; and (2) declaratory judgment that the WPC permits McKenzie to terminate its contract with Upper Missouri prior to the expiration of the contract. Summary judgment motions were argued in April 2025 and are currently pending before the court. In September 2025, the parties reached a non-binding settlement in principle, through which the parties agreed to a settlement of all claims and allegations related to the matter. The settlement in principle which has since been modified and agreed to in a formal settlement agreement, is contingent upon certain corporate and regulatory approvals, as applicable to certain of the parties. In the absence of those approvals and a stipulated dismissal, the Court in North Dakota has indicated that it plans to move forward with setting a trial date and ruling on pending motions until the parties inform the Court that the settlement has been finalized. At this time, while a loss is reasonably possible, Basin Electric does not believe that the amount of loss can be reasonably estimated pending finalization of a definitive settlement agreement and therefore has not currently made any accrual for this matter. FERC PROCEEDINGS–Effective November 1, 2019, Basin Electric ceased qualifying for an exemption from FERC’s jurisdiction under the Federal Power Act. As part of its new compliance requirements, Basin Electric submitted its WPCs and Rate Schedule A to FERC for approval. FERC accepted Basin Electric’s WPCs and 2020 Rate Schedule A subject to hearing and settlement proceedings effective September 15, 2020, and dismissed Basin Electric’s 2019 Rate Schedule A as moot. FERC subsequently accepted and consolidated Basin Electric’s 2021 Rate Schedule A with the ongoing hearing and settlement proceedings effective January 1, 2021. The FERC presiding judge held a hearing on the WPCs and 2020 and 2021 Rate Schedules A from August 28, 2023, to October 27, 2023, and from February 5, 2024, through February 7, 2024. The FERC presiding judge issued his initial decision on June 11, 2024, addressing arguments raised by Class A Member Tri-State Generation and Transmission Association, Inc. (Tri-State), Class C Members McKenzie, Minnesota Valley Electric Cooperative (MVEC), and Wright-Hennepin Cooperative Electric Association (Wright-Hennepin), and the Sierra Club. In particular, the Sierra Club argued that Basin Electric should not be allowed to recover costs in its rates relating to certain of its coal generation assets; McKenzie argued that Basin Electric should not be allowed to recover costs in its rates relating to Dakota Gas; and Tri-State, MVEC, and Wright-Hennepin argued that Basin Electric’s calculation of rates for depreciation expense and transmission service are not just and reasonable. The Initial Decision remains pending before FERC on exceptions. FERC has not indicated when it intends to act on the initial decision. In addition, FERC action remains pending on Basin Electric’s 2022, 2023, 2024, and 2025 Rate Schedules A. On July 16, 2025, Basin Electric received financing under the Rural Electrification Act of 1936. Basin Electric subsequently filed a motion at FERC to dismiss the active rate proceedings involving the WPCs and Rate Schedules A on the basis that, pursuant to Federal Power Act (FPA) Section 201(f), Basin Electric is no longer a public utility subject to FERC rate regulation and also filed notices of cancellation of its rate schedules, tariffs, and other agreements. On September 12, 2025, FERC issued an order accepting the notices of cancellation, finding that, due to Basin Electric’s change of jurisdictional status, it is no longer required to maintain tariff records with FERC. FERC denied rehearing and issued an order addressing the rehearing arguments. The cancellation order has since been appealed by Tri-State to the D.C. Circuit Court of Appeals and remains pending with the appellate court. MVEC has subsequently voluntarily dismissed its objections in this proceeding and withdrawn as a participant in the matter. In September 2025, Basin Electric and McKenzie reached a settlement in principle, through which McKenzie agreed to withdraw its objections to Basin Electric’s rates in the FERC proceedings and withdraw from any other FERC proceedings and/or appeals in which it had intervened against Basin Electric to the greatest extent possible. The settlement in principle is contingent upon execution of a mutually acceptable settlement agreement and corporate and regulatory approvals, as applicable to each party. See also “Litigation” above. On June 5, 2026, FERC denied the motion to dismiss on the basis that it “must ensure that jurisdictional rates charged to customers were just and reasonable.” Basin Electric considered these FERC proceedings and currently has not made an accrual. RUS FINANCING–On June 10, 2025, McKenzie filed with FERC a complaint against Basin Electric. The complaint requests that FERC find that Basin Electric is not authorized to obtain financing under the Rural Electrification Act of 1936 and that FERC retain jurisdiction over Basin Electric notwithstanding Basin Electric receiving such financing. Basin Electric contested the allegations of the complaint, and further contested McKenzie’s right to the relief requested under the Federal Power Act. On May 21, 2026, FERC issued an order denying the complaint, finding that McKenzie had not demonstrated that Basin Electric's actions were in violation of either Section 204 of the Federal Power Act or its blanket authorization to obtain financing. It is possible that a party to the complaint proceeding may seek rehearing by June 21, 2026. NORTHWEST RURAL PUBLIC POWER DISTRICT–On March 25, 2024, Northwest Rural Public Power District (NRPPD) filed with FERC a complaint against Basin Electric and Tri-State. The complaint requested that FERC find that NRPPD is permitted to withdraw its membership in Tri-State, terminate its wholesale electric service contract (WESC) with Tri-State, and that its withdrawal and termination is permissible under the wholesale power contract between Basin Electric and Tri-State. In December 2024, FERC issued its order denying the complaint, but finding that NRPPD’s withdrawal from Tri-State and termination of its WESC is not a breach of the wholesale power contract between Basin Electric and Tri-State. FERC denied rehearing and issued an order addressing the rehearing arguments. Basin Electric filed an appeal of the FERC order with the D.C. Circuit Court of Appeals and the matter remains pending with the appellate court. In April 2026, Basin Electric and NRPPD reached a settlement in principle, through which NRPPD will dismiss its pending appeal at the D.C. Circuit and the underlying FERC complaint. The settlement in principle is contingent on execution of a mutually acceptable settlement agreement and regulatory approval, as applicable to each party. Basin Electric considered this matter and currently has not made an accrual. Additionally, NRPPD has filed a complaint against Basin Electric in federal district court in Nebraska. In its amended complaint, NRPPD seeks a declaratory judgment that Basin Electric and Tri-State are bound by the December 2024 FERC Order that NRPPD’s withdrawal as a member of Tri-State, and therefore as a Class C Member of Basin Electric, is not a breach of the wholesale power contract for the Eastern Interconnection between Basin Electric and Tri-State. NRPPD further claims that it is a third-party beneficiary of the wholesale power contract between Basin Electric and Tri-State, and that Basin Electric has breached its obligations to Tri-State under the wholesale power contract by failing to provide NRPPD with an exit fee. Additional claims were added against Basin Electric for tortious interference with contract, tortious interference with a business relationship, and tortious interference with a prospective business relationship. Basin Electric contests the allegations of the complaint and has filed a motion to dismiss, which remains pending with the court. In April 2026, Basin Electric and NRPPD reached a settlement in principle, through which NRPPD will dismiss the pending complaint. The settlement in principle is contingent on execution of a mutually acceptable settlement agreement and regulatory approval, as applicable to each party. Basin Electric considered this complaint and currently has not made an accrual. OTHER DEBT GUARANTEE–Basin Electric guarantees, on an unsecured basis, a certain debt obligation of Dakota Coal totaling $21.4 million as of March 31, 2026. In the event Dakota Coal defaults under this obligation, Basin Electric would be required to make payments under its guarantee.

We are involved in claims, legal proceedings, investigations, and regulatory matters arising in the normal course of business. We regularly analyze relevant information and, as necessary, estimate and record accrued liabilities for legal, regulatory enforcement and other matters in which a loss or range of loss is probable of occurring and can be reasonably estimated. We believe the effect on our consolidated operating results, financial position and cash flows, if any, for the disposition of all matters pending as of March 31, 2026, other than those discussed below, will not be material.

LITIGATION–On November 7, 2019, McKenzie Electric Cooperative, Inc. (McKenzie), a Class C Member of Basin Electric and a member of Class A Member Upper Missouri G&T Electric Cooperative, Inc. (Upper Missouri), filed a lawsuit in North Dakota State Court against both Basin Electric and Upper Missouri. The complaint brought multiple claims against Basin Electric, some of which have since been dismissed. McKenzie’s remaining claims against Basin Electric are: (1) breach of the wholesale power contract (WPC) between Basin Electric and Upper Missouri (either as an alleged three-tier contract among Basin Electric, Upper Missouri and McKenzie, or with McKenzie being a third-party beneficiary to the WPC) by including losses associated with Dakota Gas in rates; and (2) declaratory judgment that the WPC permits McKenzie to terminate its contract with Upper Missouri prior to the expiration of the contract. Summary judgment motions were argued in April 2025 and are currently pending before the court. In September 2025, the parties reached a non-binding settlement in principle, through which the parties agreed to a settlement of all claims and allegations related to the matter. The settlement in principle which has since been modified and agreed to in a formal settlement agreement, is contingent upon certain corporate and regulatory approvals, as applicable to certain of the parties. In the absence of those approvals and a stipulated dismissal, the Court in North Dakota has indicated that it plans to move forward with setting a trial date and ruling on pending motions until the parties inform the Court that the settlement has been finalized. At this time, while a loss is reasonably possible, Basin Electric does not believe that the amount of loss can be reasonably estimated pending finalization of a definitive settlement agreement and therefore has not currently made any accrual for this matter.

FERC PROCEEDINGS–Effective November 1, 2019, Basin Electric ceased qualifying for an exemption from FERC’s jurisdiction under the Federal Power Act. As part of its new compliance requirements, Basin Electric submitted its WPCs and Rate Schedule A to FERC for approval. FERC accepted Basin Electric’s WPCs and 2020 Rate Schedule A subject to hearing and settlement proceedings effective September 15, 2020, and dismissed Basin Electric’s 2019 Rate Schedule A as moot. FERC subsequently accepted and consolidated Basin Electric’s 2021 Rate Schedule A with the ongoing hearing and settlement proceedings effective January 1, 2021. The FERC presiding judge held a hearing on the WPCs and 2020 and 2021 Rate Schedules A from August 28, 2023, to October 27, 2023, and from February 5, 2024, through February 7, 2024. The FERC presiding judge issued his initial decision on June 11, 2024, addressing arguments raised by Class A Member Tri-State Generation and Transmission Association, Inc. (Tri-State), Class C Members McKenzie, Minnesota Valley Electric Cooperative (MVEC), and Wright-Hennepin Cooperative Electric Association (Wright-Hennepin), and the Sierra Club. In particular, the Sierra Club argued that Basin Electric should not be allowed to recover costs in its rates relating to certain of its coal generation assets; McKenzie argued that Basin Electric should not be allowed to recover costs in its rates relating to Dakota Gas; and Tri-State, MVEC, and

Wright-Hennepin argued that Basin Electric’s calculation of rates for depreciation expense and transmission service are not just and reasonable. The Initial Decision remains pending before FERC on exceptions. FERC has not indicated when it intends to act on the initial decision. In addition, FERC action remains pending on Basin Electric’s 2022, 2023, 2024, and 2025 Rate Schedules A.

On July 16, 2025, Basin Electric received financing under the Rural Electrification Act of 1936. Basin Electric subsequently filed a motion at FERC to dismiss the active rate proceedings involving the WPCs and Rate Schedules A on the basis that, pursuant to Federal Power Act (FPA) Section 201(f), Basin Electric is no longer a public utility subject to FERC rate regulation and also filed notices of cancellation of its rate schedules, tariffs, and other agreements. On September 12, 2025, FERC issued an order accepting the notices of cancellation, finding that, due to Basin Electric’s change of jurisdictional status, it is no longer required to maintain tariff records with FERC. FERC denied rehearing and issued an order addressing the rehearing arguments. The cancellation order has since been appealed by Tri-State to the D.C. Circuit Court of Appeals and remains pending with the appellate court. MVEC has subsequently voluntarily dismissed its objections in this proceeding and withdrawn as a participant in the matter. In September 2025, Basin Electric and McKenzie reached a settlement in principle, through which McKenzie agreed to withdraw its objections to Basin Electric’s rates in the FERC proceedings and withdraw from any other FERC proceedings and/or appeals in which it had intervened against Basin Electric to the greatest extent possible. The settlement in principle is contingent upon execution of a mutually acceptable settlement agreement and corporate and regulatory approvals, as applicable to each party. See also “Litigation” above. On June 5, 2026, FERC denied the motion to dismiss on the basis that it “must ensure that jurisdictional rates charged to customers were just and reasonable.” Basin Electric considered these FERC proceedings and currently has not made an accrual.

RUS FINANCING–On June 10, 2025, McKenzie filed with FERC a complaint against Basin Electric. The complaint requests that FERC find that Basin Electric is not authorized to obtain financing under the Rural Electrification Act of 1936 and that FERC retain jurisdiction over Basin Electric notwithstanding Basin Electric receiving such financing. Basin Electric contested the allegations of the complaint, and further contested McKenzie’s right to the relief requested under the Federal Power Act. On May 21, 2026, FERC issued an order denying the complaint, finding that McKenzie had not demonstrated that Basin Electric's actions were in violation of either Section 204 of the Federal Power Act or its blanket authorization to obtain financing. It is possible that a party to the complaint proceeding may seek rehearing by June 21, 2026.

NORTHWEST RURAL PUBLIC POWER DISTRICT–On March 25, 2024, Northwest Rural Public Power District (NRPPD) filed with FERC a complaint against Basin Electric and Tri-State. The complaint requested that FERC find that NRPPD is permitted to withdraw its membership in Tri-State, terminate its wholesale electric service contract (WESC) with Tri-State, and that its withdrawal and termination is permissible under the wholesale power contract between Basin Electric and Tri-State. In December 2024, FERC issued its order denying the complaint, but finding that NRPPD’s withdrawal from Tri-State and termination of its WESC is not a breach of the wholesale power contract between Basin Electric and Tri-State. FERC denied rehearing and issued an order addressing the rehearing arguments. Basin Electric filed an appeal of the FERC order with the D.C. Circuit Court of Appeals and the matter remains pending with the appellate court. In April 2026, Basin Electric and NRPPD reached a settlement in principle, through which NRPPD will dismiss its pending appeal at the D.C. Circuit and the underlying FERC complaint. The settlement in principle is contingent on execution of a mutually acceptable settlement agreement and regulatory approval, as applicable to each party. Basin Electric considered this matter and currently has not made an accrual.

Additionally, NRPPD has filed a complaint against Basin Electric in federal district court in Nebraska. In its amended complaint, NRPPD seeks a declaratory judgment that Basin Electric and Tri-State are bound by the December 2024 FERC Order that NRPPD’s withdrawal as a member of Tri-State, and therefore as a Class C Member of Basin Electric, is not a breach of the wholesale power contract for the Eastern Interconnection between Basin Electric and Tri-State. NRPPD further claims that it is a third-party beneficiary of the wholesale power contract between Basin Electric and Tri-State, and that Basin Electric has breached its obligations to Tri-State under the wholesale power contract by failing to provide NRPPD with an exit fee. Additional claims were added against Basin Electric for tortious interference with contract,

tortious interference with a business relationship, and tortious interference with a prospective business relationship. Basin Electric contests the allegations of the complaint and has filed a motion to dismiss, which remains pending with the court. In April 2026, Basin Electric and NRPPD reached a settlement in principle, through which NRPPD will dismiss the pending complaint. The settlement in principle is contingent on execution of a mutually acceptable settlement agreement and regulatory approval, as applicable to each party. Basin Electric considered this complaint and currently has not made an accrual.