Constellation Energy Corp

13. Debt and Credit Agreements

Long-Term Debt

Calpine Acquisition

Upon completion of the acquisition of Calpine in January 2026, we assumed approximately $12.6 billion of debt inclusive of approximately $7.6 billion of corporate long-term debt, including senior unsecured and secured notes and corporate term loans in addition to approximately $5.0 billion of various project financing arrangements. Pursuant to the Exchange Offers discussed below, we issued new notes in January 2026 effectively replacing $2.3 billion of Calpine's senior unsecured and secured notes with Constellation senior unsecured notes. Using the proceeds from our January 2026 bond issuance, as discussed below, along with cash on hand and short-term debt, we repaid $2.5 billion of Calpine corporate term loans immediately after the acquisition closing, $1.25 billion of Calpine senior secured first lien notes in February 2026, and $1.4 billion of Calpine senior unsecured notes in March 2026.

As discussed above, the following project financing arrangements were assumed as part of the acquisition:

Geysers Power Company, LLC. We acquired the GPC first lien senior secured term loan facility, which includes a term loan and $250 million letter of credit facility, up to $50 million of which may be used for loans to finance energy storage projects (the sub-facility). At acquisition, outstanding borrowings under the term loan and sub-facility were approximately $1.35 billion and $45 million, respectively. The GPC facility is secured by substantially all of the real and personal property of GPC and subsidiaries, primarily consisting of the Geysers Assets. The facility matures May 2029 and bears interest at SOFR plus 1.625%. As of September 30, 2026, there were $1.2 billion and $42 million of borrowings outstanding under the term loan and sub-facility, respectively.

Calpine Construction Finance Company, L.P. We acquired the CCFC first lien senior secured term loan facility with $2.1 billion outstanding borrowings at acquisition. The CCFC term loan facility is secured by certain real and personal property of CCFC, primarilysix natural gas-fired power plants. Brazos Valley Energy Center (Brazos), f/k/a Jack A. Fusco Energy Center secured the facility prior to its release following the plant's sale in October 2026. See Note 2 — Mergers, Acquisitions, and Dispositions for additional information regarding the sale. The term loan matures July 2030 and bears interest at SOFR plus 1.75%. As of September 30, 2026, there was $2.1 billion of borrowings outstanding under the term loan.

CDHI Intermediate Holdco, LLC. We acquired the CDHI facility (CDHI Revolver), a $1.2 billion letter of credit facility, up to $400 million of which can be used for revolving loans to finance construction of renewable energy projects. At acquisition, outstanding borrowings under the CDHI Revolver were $319 million. The CDHI Revolver was secured by substantially all of the assets of CDHI's subsidiaries in accordance with the terms of the agreement. In March 2026 and April 2026, the capacity of the CDHI Revolver was reduced by an aggregate $818 million. In June 2026, in connection with the capacity reductions, the lenders consented to the release of four plants from the collateral securing the facility; the two York Energy Centers, Sutter Energy Center, and South Point Energy Center. Thetwo York Energy Centers which partially secured the CDHI Revolver are being sold. See Note 2 — Mergers, Acquisitions, and Dispositions for additional information regarding the sale. Redemptions prior to March 2026 were based on SOFR plus 2.25%. Effective March 2026 through the termination of the facility, redemptions were based on SOFR plus 2.375%. As of September 30, 2026, there was $269 million of borrowings outstanding under the credit facility. In October 2026, we repaid all outstanding borrowings under the CDHI Revolver, cancelled any outstanding letters of credit, and terminated all commitments which effectively terminated the facility.

Nova Power, LLC. We acquired the Nova Power, LLC credit agreement, which is comprised of a term loan, with $591 million of outstanding borrowings at acquisition, and an $80 million letter of credit facility. The agreement financed a portion of the cost of the development, construction, maintenance, and operation of the Nova Power battery storage project, and is secured by Nova Power's real and personal property. The credit agreement matures September 2031 and bears interest at SOFR plus 1.75%. As of September 30, 2026, there was $560 million of borrowings outstanding under the credit agreement.

Greenfield L.P. We acquired the Greenfield L.P. credit facility, which includes a term loan, with $342 million of outstanding borrowings at acquisition, and several letters of credit facilities, with issuing capacity of approximately $75 million. The Greenfield L.P. credit facility is secured by certain real and personal property, primarily the Greenfield Energy Center in Ontario, Canada. The credit facility matures November 2030 and bears interest at CORRA plus 1.875%. As of September 30, 2026, there was $311 million of borrowings outstanding under the facility.

Pin Oak Creek Energy Center LLC. We acquired Pin Oak Creek Energy Center's obligations under a credit agreement with Texas Energy Fund (TEF), as lender, as administered by the Public Utility Commission of Texas (PUCT). The loan proceeds were used to finance eligible costs for the development (as defined in the agreement), construction, and installation of Pin Oak Creek Energy Center in Fairfield, Texas. The loan had outstanding borrowings of $230 million at acquisition. The loan matures October 2045 and bears interest at 3%. As of September 30, 2026, there was $277 million of borrowings outstanding under the loan.

Calpine Credit Agreements

As a result of the acquisition, we assumed Calpine's corporate secured and unsecured letters of credit facilities with capacity totaling $525 million and $200 million, respectively, at the time of acquisition.

The total capacity of assumed project and corporate credit facilities discussed above was approximately $2.3 billion at the time of acquisition, which was reduced by outstanding borrowings under the GPC facility and CDHI Revolver. At the time of acquisition, there were outstanding letters of credit on the assumed facilities of approximately $1.7 billion. See the Credit Facilities table below for additional information on credit facilities associated with these project financing arrangements.

Debt Exchange Offering

In December 2025, in connection with the planned acquisition of Calpine, we commenced private exchange offers and related consent solicitations for certain outstanding debt of Calpine (the Exchange Offers). We solicited consents from holders of the Calpine debt to amend the notes and the related indentures under which they were issued to eliminate substantially all of the restrictive covenants, restrictive provisions and events of default, other than payment-related and bankruptcy-related events of default. In January 2026, we completed the Exchange Offers, pursuant to which $2.3 billion of Calpine senior secured and unsecured notes were exchanged for Constellation senior unsecured notes.

The terms of the debt issued under the exchange are as follows:

Senior Note Issuance

In January 2026, we issued senior unsecured notes totaling $2.75 billion, the proceeds from which were used to pay down Calpine debt assumed. In May 2026, we issued senior unsecured notes totaling $2.2 billion and used the net proceeds (i) to repay short-term borrowings, including commercial paper obligations and (ii) for general corporate purposes. The terms of the debt issuances are reflected in the Debt Issuances and Redemptions table below.

Long-term Debt Summary

The following table presents the outstanding long-term debt, as of September 30, 2026 and December 31, 2025:

(a)Includes debt assumed in acquisition of Calpine.

(b)The Tax-exempt notes have a maturity date of June 2029 to April 2053, and a mandatory purchase date that ranges from April 2028 to June 2029.

Debt Issuances and Redemptions

During the nine months ended September 30, 2026, the following long-term debt was issued (redeemed):

(a)Does not include debt exchange activity discussed above.

(b)Relates to January 2026 debt issuance used to pay down Calpine corporate debt assumed.

DOE Loan Guarantees

Crane Clean Energy Center

In November 2025, the DOE Office of Energy Dominance Financing issued a guarantee for up to $1.0 billion for an unsecured loan from the Federal Financing Bank to support the restart of the Crane Clean Energy Center. The loan matures November 2055. Interest rates on the loan are fixed upon each advance at a spread of 0.375% above U.S. Treasuries of comparable maturity. There have been no borrowings on this loan as of the date of this filing.

Nuclear Uprates

In October 2026, we signed a conditional loan commitment with the DOE Office of Energy Dominance Financing. Subject to the execution of a loan agreement, the DOE would issue a guarantee for up to $5.0 billion for an unsecured loan from the Federal Financing Bank to support uprates at various nuclear facilities. The loan would have a 30-year term. Interest rates would be fixed upon each advance at a spread of 0.375% above U.S. Treasuries of comparable maturity.

Short-Term Borrowings

We meet our short-term liquidity requirements primarily through the issuance of commercial paper. We may use our credit facility for general corporate purposes, including meeting short-term funding requirements and the issuance of letters of credit.

Credit Agreements

In September 2025, we amended our existing revolving credit facility (RCF) to increase the available aggregate commitment from $4.5 billion to $7.0 billion, which included incremental revolving credit commitments of $2.5 billion and extension of the maturity date to September 2030. The incremental commitments became available upon the closing of the Calpine acquisition in January 2026. The RCF may be drawn down in the form of loans and/or to support commercial paper and letter of credit issuances.

The RCF fixed facility fee rate is 0.175% and borrowings under the RCF bear interest at a rate based upon either the Daily Simple SOFR rate or a Term SOFR rate, plus an adder based upon our credit rating. The adders for the Daily Simple SOFR-based borrowings and Term SOFR borrowings are 0.075% and 1.075%, respectively. The letters of credit bear interest at a rate of 1.075%.

If we were to lose our investment grade credit rating, the maximum adders for Daily Simple SOFR rate borrowings and Term SOFR rate borrowings would be 1.00% and 2.00%, respectively. The credit agreements also require us to pay facility fees based upon the aggregate commitments. The fees vary depending upon our credit rating.

Accounts Receivable Facility

The Accounts Receivable Facility (the Facility) provides NER access to revolving loans from a number of financial institutions (Lenders) secured by certain customer accounts receivable. The maximum funding limit of the Facility is $1.5 billion and matures December 2027. Draws and repayments related to the Facility will be reflected as Proceeds from short-term borrowings and Repayments of short-term borrowings, respectively, in the Consolidated Statements of Cash Flows. Draws on the Facility bear interest at a commercial paper rate or a Daily One Month Term SOFR or Term SOFR rate, plus an adder of 0.10% per annum. In the first quarter of 2026, we drew on the Facility in full. Subsequently, in the second quarter of 2026, we used the proceeds of the term loan and senior notes issued to repay $1.1 billion of the Facility. As of September 30, 2026, $400 million of the Facility was drawn on and outstanding.

The Facility requires the balance of eligible receivables to be maintained at or above the balance of cash proceeds received from the Lenders. To the extent the eligible receivables decrease below such balance, we are required to repay cash to the Lenders. When eligible receivables exceed cash proceeds, we have the ability to increase the cash proceeds received up to the maximum funding limit. As of September 30, 2026, the balance of our eligible receivables exceeded the cash proceeds outstanding from the Lenders.

Credit Facilities Summary

As of September 30, 2026 and December 31, 2025, we had the following aggregate capacity, credit facility borrowings and available capacity under our respective credit facilities:

(a)Excludes an additional outstanding letter of credit which was not issued under these facilities of $15 million as of September 30, 2026 and December 31, 2025. See Note 15 — Commitments and Contingencies for additional information.

(b)Our commercial paper program is supported by the revolving credit agreement. In order to maintain our commercial paper program in the amounts indicated above, we must have a credit facility in place, at least equal to the amount of our commercial paper program. As of September 30, 2026 and December 31, 2025, the maximum program size of our commercial paper program was $7.0 billion and $4.5 billion, respectively. We do not issue commercial paper in an aggregate amount exceeding the then available capacity under our credit facility. The weighted average interest rate on commercial paper borrowings was 4.28% as of September 30, 2026. There were no commercial paper borrowings outstanding as of December 31, 2025.

(c)In 2026, we entered into or amended bilateral credit facilities, increasing aggregate letter of credit capacity by $1,025 million, converting certain facilities to uncommitted status and extending certain maturities. As of September 30, 2026, uncommitted facilities totaled $3,450 million. Such facilities are subject to issuer discretion, have no stated maturity and may be terminated by either party upon notice.

(d)Includes corporate and project-related facilities assumed in connection with Calpine acquisition in January 2026.

(e)In October 2026, we cancelled any outstanding letters of credit and terminated all commitments under the CDHI Revolver as part of the facility termination.

(f)The maximum amount of the bank commitment is not to exceed $971 million. The aggregate available capacity of the facility is subject to market fluctuations based on the value of U.S. Treasury Securities which determines the amount of collateral held in the trust. We may post additional collateral to borrow up to the maximum bank commitment. As of September 30, 2026 and December 31, 2025, without posting additional collateral, the actual availability of facility, prior to outstanding letters of credit was $966 million and $959 million, respectively.

Short-Term Loan Agreements

As of September 30, 2026 and December 31, 2025, we had the following short-term loan agreements, which are unsecured and reflected in Short-term borrowings in the Consolidated Balance Sheets:

Debt Covenants

As of September 30, 2026, we are in compliance with all debt covenants.