
	Expiration within
	2026		2027		2028		2029		2030		2031 and thereafter		Total
Letters of credit	$	3,402	$	1,036	$	120	$	—	$	1	$	—	$	4,559
Surety bonds(a)	581		261		78		—		—		545		1,465
Guarantee under the Calpine AR Facility(b)	550		—		—		—		—		—		550
Total commercial commitments	$	4,533	$	1,297	$	198	$	—	$	1	$	545	$	6,574

(b)We have guaranteed the performance of Calpine Energy Solutions, LLC to Calpine Receivables, LLC under the Calpine AR Facility. The commitment represents the gross amount of sold receivables that are currently outstanding, limited to $550 million per the guarantee agreement. Refer to Note 7 — Accounts Receivable for additional information.

Following the acquisition of Calpine in January 2026, the Company has assumed additional first-priority liens on Calpine assets, which are currently subject to first priority liens under various debt agreements, as collateral under certain of our power and natural gas agreements and certain of the interest rate swaps in order to reduce the cash collateral and letters of credit that would otherwise be provided to the counterparties under such agreements. The counterparties under such agreements share the benefits of the collateral subject to such first priority liens pro rata with the lenders under various debt agreements. As of March 31, 2026, the exposure was $220 million under these first priority liens for power and natural gas agreements and no exposure for the interest rate swaps.

General. Our operations have in the past, and may in the future, require substantial expenditures to comply with environmental laws. Additionally, under Federal and state environmental laws, we are generally liable for the costs of remediating environmental contamination of property currently or formerly owned by us and of property contaminated by hazardous substances generated by us. We own or lease several real estate parcels, including parcels on which our operations or the operations of others may have resulted in contamination by substances that are considered hazardous under environmental laws. In addition, we are currently involved in proceedings relating to sites where hazardous substances have been deposited and may be subject to additional proceedings in the future. Unless otherwise disclosed, we cannot reasonably estimate whether we will incur significant liabilities for additional investigation and remediation costs at these or additional sites identified by us, environmental agencies, or others. Additional costs could have a material, unfavorable impact on our consolidated financial statements.

As of March 31, 2026 and December 31, 2025, we had accrued undiscounted amounts for environmental liabilities of $9 million in Accounts payable and accrued expenses and $169 million in Other deferred credits and other liabilities in the Consolidated Balance Sheets. See Note 18 — Commitments and Contingencies of our 2025 Form 10-K for additional information on environmental remediation matters. As of March 31, 2026, and through the date of filing, there have been no material changes in amounts recognized for the matters discussed in our 2025 Form 10-K.

We are involved in various litigation matters that are being defended and handled in the ordinary course of business. The assessment of whether a loss is probable or reasonably possible, and whether the loss or a range of loss is estimable, often involves a series of complex judgments about future events. We maintain accruals for such losses that are probable of being incurred and subject to reasonable estimation. Management is sometimes unable to estimate an amount or range of reasonably possible loss, particularly where (1) the damages sought are indeterminate, (2) the proceedings are in the early stages, or (3) the matters involve novel or unsettled legal theories. In such cases, there is considerable uncertainty regarding the timing or ultimate resolution of such matters, including a possible eventual loss.

As of March 31, 2026 and December 31, 2025, we had accrued $28 million and $15 million, respectively, in Accounts payable and accrued expenses and $108 million and $113 million, respectively, in Other deferred credits and other liabilities in the Consolidated Balance Sheets for liabilities related to litigation matters, including asbestos personal injury claims. See Note 18 — Commitments and Contingencies of our 2025 Form 10-K for additional information on asbestos personal injury claims

Impacts of the February 2021 Extreme Cold Weather Event and Texas-based Generating Assets Outages. Calpine was acquired on January 7, 2026, and is party to the same ongoing litigation proceedings as Constellation. See Note 18 — Commitments and Contingencies of our 2025 Form 10-K for additional information on this matter, which is likewise representative of the ongoing proceedings as it pertains to Calpine.

In March 2026, the Supreme Court of Texas denied plaintiffs’ petitions for a writ of mandamus in all five bellwether appeals. Plaintiffs have stated that they intend to seek rehearing before the Court. If the rehearing petitions in the bellwether cases are denied, the parties would return to the Multi-District-Litigation court to dispose of all of the remaining Winter Storm Uri tort claims pending against the power generator defendants.