Summit Midstream Corp

(A)Disclosure in lieu of reporting on a Current Report on Form 8-K.

On March 16, 2026 (the “Closing Date”), Summit Permian Transmission, an unrestricted subsidiary of SMLP that directly owns SMLP’s 70% interest in Double E, entered into a Credit Agreement with EPIC Administration, LLC (as administrative agent), the lenders party thereto from time to time and Nuveen Alternative Advisors, LLC (as sole lead arranger) (the “New Permian Transmission Credit Agreement”).

The New Permian Transmission Credit Agreement provides Summit Permian Transmission with an up to $440.0 million senior secured term loan facility consisting of $340.0 million in initial term loan commitments, $50.0 million in delayed draw term loan commitments and a $50 million uncommitted incremental term loan facility. The New Permian Transmission Facility will be used to: repay in full the Permian Transmission Credit Facilities, redeem in full the outstanding Subsidiary Series A Preferred Units, make a distribution to the Company, fund the debt service reserve account under the New Permian Transmission Facility, pay fees and expenses in connection with the New Permian Transmission Credit Agreement and related transactions, and fund general corporate purposes. The New Permian Transmission Facility bears interest at SOFR plus 4.00% per annum payable quarterly and matures on the fifth anniversary of the Closing Date. The term loans will amortize quarterly beginning in March 2027 in an amount equal to 0.25% of the principal amount of term loans outstanding on each quarterly payment date.

The delayed draw term loan commitments are available to be drawn on an as-needed basis for a period of 30 months following the Closing Date, so long as there are no defaults, events of default, certain customary representations and warranties are true and correct in all material respects and certification is provided that Summit Permian Transmission satisfies the financial covenants under the New Permian Transmission Credit Agreement on a pro forma basis taking into account such delayed draw. The delayed draw commitments are subject to a commitment fee equal to 1.00% per annum calculated on any unused and available delayed draw commitments.

The New Permian Transmission Credit Agreement includes customary representations and warranties, affirmative covenants, negative covenants, and events of default with customary cure periods, knowledge qualifiers and materiality qualifiers. The New Permian Transmission Credit Agreement also includes financial covenants based on certain maximum total debt to EBITDA ratios and certain minimum debt service coverage ratios, in each case as defined in the New Permian Transmission Credit Agreement. Events of default include non-payment of principal and interest, non-compliance with affirmative and negative covenants, inaccuracy of representations and warranties, cross payment default and cross acceleration, change of control, termination of material contracts, revocation of material permits and other customary events of default. Summit Permian Transmission is required to take all actions within its control to comply with any such covenants that apply to Double E. Secured interests in the equity and assets of Summit Permian Transmission, including its 70% direct membership interest in Double E, have been granted under the New Permian Transmission Credit Agreement.

Summit Permian Transmission will also be required to maintain a 3-month debt service reserve, which can be supported by letters of credit. In addition, the New Permian Transmission Credit Agreement allows for restricted payments so long as there are no defaults or events of default and Summit Permian Transmission maintains a total debt to EBITDA ratio of at least 6.00:1.00.

In connection with entering into the New Permian Transmission Credit Agreement, Summit Permian Transmission entered into a $7.0 million letter of credit arrangement.

The foregoing description of the New Permian Transmission Credit Agreement is a summary and is qualified in its entirety by reference to the full text of the New Permian Transmission Credit Agreement, a copy of which is filed as Exhibit 10.15 to this Annual Report on Form 10-K and which is incorporated herein by reference.

(B)Insider trading arrangements and policies.

During the three months ended December 31, 2025, no director or officer of the Company adopted orterminated a “Rule 10b5-1 trading arrangement” or “non-Rule 10b5-1 trading arrangement,” as each term is defined in Item 408(a) of Regulation S-K.