Contract

GRANTOR JOINDER AGREEMENT GRANTOR JOINDER AGREEMENT dated as of December 4, 2024 (the “Grantor Joinder Agreement”), to the INTERCREDITOR AGREEMENT dated as of November 2, 2021 (the “Intercreditor Agreement”), among BANK OF AMERICA, N.A., as Initial First Lien Representative and Initial First Lien Collateral Agent, REGIONS BANK, not in its individual capacity but solely in its capacity as trustee under the Initial Second Lien Indenture, as Initial Second Lien Representative, REGIONS BANK, not in its individual capacity but solely in its capacity as collateral agent under the Initial Second Lien Indenture, as Initial Second Lien Collateral Agent, and the additional Representatives and Collateral Agents from time to time a party thereto, and acknowledged and agreed to by SUMMIT MIDSTREAM HOLDINGS, LLC, a Delaware limited liability company (the “Company”), and the other Grantors. Capitalized terms used herein but not otherwise defined herein shall have the meanings assigned to such terms in the Intercreditor Agreement. The undersigned, TALL OAK MIDSTREAM OPERATING, LLC, a Delaware limited liability company (“Tall Oak”), TALL OAK WOODFORD, LLC, a Delaware limited liability company (“Woodford”), BCZ LAND HOLDINGS, LLC, a Delaware limited liability company (“BCZ”), and VM ARKOMA STACK, LLC, a Delaware limited liability company (“VM”, and together with Tall Oak, Woodford and BCZ, collectively, the “New Grantors” and each, a “New Grantor”) wishes to acknowledge and agree to the Intercreditor Agreement and become a party thereto to the limited extent contemplated by Section 8.18 thereof and to acquire and undertake the rights and obligations of a Grantor thereunder. Accordingly, each New Grantor agrees as follows for the benefit of the Representatives, the Collateral Agents and the Claimholders: Section 1. Accession to the Intercreditor Agreement. Each New Grantor (a) acknowledges and agrees to, and becomes a party to the Intercreditor Agreement as a Grantor to the limited extent contemplated by Section 8.18 thereof, (b) agrees to all the terms and provisions of the Intercreditor Agreement and (c) shall have all the rights and obligations of a Grantor under the Intercreditor Agreement. This Grantor Joinder Agreement supplements the Intercreditor Agreement and is being executed and delivered by the New Grantor pursuant to Section 8.20 of the Intercreditor Agreement. Section 2. Representations, Warranties and Acknowledgement of the New Grantors. Each New Grantor represents and warrants to each Representative, each Collateral Agent and to the Claimholders that (a) it has full power and authority to enter into this Grantor Joinder Agreement, in its capacity as Grantor and (b) this Grantor Joinder Agreement has been duly authorized, executed and delivered by it and constitutes its legal, valid and binding obligation, enforceable against it in accordance with the terms of this Grantor Joinder Agreement. Section 3. Counterparts. This Grantor Joinder Agreement may be executed in counterparts (and by different parties hereto in different counterparts), each of which shall constitute an original, but all of which when taken together shall constitute a single contract. Delivery of an executed counterpart of a signature page of this Grantor Joinder Agreement or any document or instrument delivered in connection herewith by telecopy or other electronic means shall be effective as delivery of a manually executed counterpart of this Grantor Joinder Agreement or such other document or instrument, as applicable. The terms of the final sentence of Section 8.16 of the Intercreditor Agreement shall apply to this Grantor Joinder Agreement, mutatis mutandis. Exhibit 10.3

Section 4. Full Force and Effect. Except as expressly supplemented hereby, the Intercreditor Agreement shall remain in full force and effect. Section 5. Section Headings. Section heading used in this Grantor Joinder Agreement are for convenience of reference only and are not to affect the construction hereof or to be taken in consideration in the interpretation hereof. Section 6. Benefit of Agreement. The agreements set forth herein or undertaken pursuant hereto are for the benefit of, and may be enforced by, any party to the Intercreditor Agreement subject to any limitations set forth in the Intercreditor Agreement with respect to the Grantors. Section 7. Governing Law. THIS GRANTOR JOINDER AGREEMENT, AND ANY DISPUTE, CLAIM OR CONTROVERSY ARISING OUT OF OR RELATING TO THIS GRANTOR JOINDER AGREEMENT (WHETHER ARISING IN CONTRACT, TORT OR OTHERWISE) SHALL BE GOVERNED BY, AND CONSTRUED AND INTERPRETED IN ACCORDANCE WITH, THE LAW OF THE STATE OF NEW YORK WITHOUT REGARD TO CONFLICTS OF LAW RULES THAT WOULD RESULT IN THE APPLICATION OF A DIFFERENT GOVERNING LAW (OTHER THAN ANY MANDATORY PROVISIONS OF THE UCC RELATING TO THE LAW GOVERNING PERFECTION AND THE EFFECT OF PERFECTION OR PRIORITY OF THE SECURITY INTERESTS IN THE COLLATERAL). Section 8. Severability. Any provision of this Agreement that is prohibited or unenforceable in any jurisdiction shall, as to such jurisdiction, be ineffective to the extent of such prohibition or unenforceability without invalidating the remaining provisions hereof, and any such prohibition or unenforceability in any jurisdiction shall not invalidate or render unenforceable such provision in any other jurisdiction. The parties hereto shall endeavor in good faith negotiations to replace any invalid, illegal or unenforceable provisions with valid provisions the economic effect of which comes as close as possible to those of the invalid, illegal or unenforceable provisions. Section 9. Notices. All communications and notices hereunder shall be in writing and given as provided in Section 8.11 of the Intercreditor Agreement. All communications and notices hereunder to any New Grantor shall be given to it at the address set forth below, which information supplements Section 8.11 of the Intercreditor Agreement. Address for notices: 000 Xxxxxxxxx Xxxxxx Xxxxx 0000 Xxxxxxx, Xxxxx 00000 Attention: Xxxxx Xxxxxxxx, General Counsel With a copy (which shall not constitute notice) to: Xxxxxxxx & Xxxxx LLP 000 Xxxx Xxxxxx Xxxxxxx, Xxxxx 00000 Attention: Xxxxxxx Xxxxxxx Section 10. Miscellaneous. The provisions of Section 8 of the Intercreditor Agreement will apply with like effect to this Grantor Joinder Agreement.

Signature Page to Grantor Joinder Agreement IN WITNESS WHEREOF, each New Grantor has duly executed this Grantor Joinder Agreement to the Intercreditor Agreement as of the day and year first above written. TALL OAK MIDSTREAM OPERATING, LLC By: /s/ Xxxxxxx X. Xxxxx Name: Xxxxxxx X. Xxxxx Title: Executive Vice President and Chief Financial Officer TALL OAK WOODFORD, LLC By: /s/ Xxxxxxx X. Xxxxx Name: Xxxxxxx X. Xxxxx Title: Executive Vice President and Chief Financial Officer BCZ LAND HOLDINGS, LLC By: /s/ Xxxxxxx X. Xxxxx Name: Xxxxxxx X. Xxxxx Title: Executive Vice President and Chief Financial Officer VM ARKOMA STACK, LLC By: /s/ Xxxxxxx X. Xxxxx Name: Xxxxxxx X. Xxxxx Title: Executive Vice President and Chief Financial Officer