X0609 4 2026-10-01 0 0002024218 Summit Midstream Corp SMC 0001823482 Johnston James David false C/O SUMMIT MIDSTREAM CORPORATION 910 LOUISIANA STREET, SUITE 4200 HOUSTON TX 77002 0 1 0 0 Executive VP, GC, CCO and Secy 1 Common Stock 2026-10-01 4 S 0 2600 30.51 D 72757 D These Common Stocks were sold in compliance with a qualified selling plan adopted by the reporting person pursuant to Rule 10b5-1 under the Securities Exchange Act of 1934, as amended. The price reported in Column 4 is a weighted average price and has been rounded to the nearest cent. These Common Stocks were sold in multiple transactions at prices ranging from $29.85 to $30.75, inclusive. The reporting person undertakes to provide to Summit Midstream Corporation, any security holder of Summit Midstream Corporation, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of Common Stocks sold at each separate price within the ranges set forth in footnote 2 to this Form 4. /s/ James David Johnston 2026-10-02