Summit Midstream SEC Filings

Summit Midstream Corp executive Matthew B. Sicinski, Senior VP and CAO, reported equity award activity and related tax withholding. On January 16, 2026, 3,593 corporation restricted stock units were exercised and converted to common stock at an exercise price of $0, reflecting the vesting of part of a prior award. Each unit is economically equivalent to one share of common stock.

On the same date, 1,066 common shares were withheld at $26.81 per share to cover tax liabilities tied to the vesting. After these transactions, Sicinski directly owned 31,347 common shares and 29,362 corporation restricted stock units, which will vest over time under earlier grant terms and may settle in shares or cash at the issuer’s discretion.

Summit Midstream Corp executive James David Johnston reported equity award activity. On January 16, 2026, 10,794 corporation restricted stock units vested and were converted into an equal number of common shares at an exercise price of $0. Of these, 2,923 common shares were withheld at $26.81 per share to cover tax obligations, leaving Johnston with 57,687 common shares held directly after the transactions.

Each corporation restricted stock unit equals one share of common stock, and the vested units were part of an award where one-third vested on January 16, 2026, with the remaining units scheduled to vest on the third anniversary of the January 18, 2024 reference date, subject to continued employment. After this vesting event, Johnston also held 89,717 corporation restricted stock units, which include other tranches with different vesting dates and are settled in stock or cash at the issuer’s discretion.

Summit Midstream Corp Chairman, President and CEO J. Heath Deneke reported equity award activity involving restricted stock units and common shares. On January 16, 2026, 32,754 corporation restricted stock units were converted at an exercise price of $0, resulting in the acquisition of 32,754 shares of common stock. The filing shows that 8,216 common shares were withheld at a price of $26.81 per share to cover tax liabilities associated with the vesting.

After these transactions, Deneke directly held 290,708 shares of common stock and 283,556 corporation restricted stock units. Each corporation restricted stock unit is economically equivalent to one share of common stock and is settled in stock or cash upon vesting, with related distribution equivalent rights that pay accumulated distributions in cash on the vesting date.

Summit Midstream Corp received an updated ownership report from investor He Zhengxu, who filed an amended Schedule 13G. He reports beneficial ownership of 1,511,500 shares of Summit Midstream common stock, representing 8.1% of the outstanding class as of the reported event date of 12/31/2025. He has sole power to vote and dispose of all these shares and no shared voting or dispositive power.

The filing states that the securities were acquired and are held in the ordinary course of business and not for the purpose of changing or influencing control of Summit Midstream Corp.

Summit Midstream Corporation reported that its board unanimously appointed Carolyn J. Stone as an independent Class II director, effective March 16, 2026. She will fill the board seat currently held by Marguerite Woung-Chapman, who will retire as of midnight on March 15, 2026. Ms. Woung-Chapman stated she has no disagreement with the company on its operations, practices, or policies, and there is no issue related to her retirement that needs to be brought to shareholders’ attention.

The company highlighted Ms. Stone’s extensive background in financial, accounting, and audit matters, as well as public-company governance and reporting. Her prior roles include serving as Senior Vice President, Chief Financial Officer, and Treasurer of Civeo Corporation, along with earlier executive and accounting leadership positions. She is a Certified Public Accountant and will receive compensation under Summit Midstream’s standard director compensation program.

Summit Midstream Corporation reported higher activity in Q3. Total revenues were $146.9 million, up from $102.4 million a year ago, driven by growth in gathering fees and sales of natural gas, NGLs and condensate. After preferred distributions and noncontrolling interests, the company posted a net loss attributable to Summit Midstream Corporation of $1.6 million (basic EPS $(0.13)).

For the nine months, revenues were $419.8 million versus $322.6 million last year, with interest expense lower at $70.6 million compared to $95.0 million. Operating cash flow reached $79.9 million. The company completed the Moonrise Acquisition for approximately $90.0 million (including $70.0 million cash and 462,265 shares of common stock) and continued integrating Tall Oak (aggregate consideration $425.0 million plus potential earn-out up to $25.0 million).

On the balance sheet, 2029 Secured Notes outstanding were $825.0 million and the Amended and Restated ABL Facility balance was $150.0 million as of September 30, 2025. Shares outstanding were 12,261,954 common and 6,524,467 Class B as of October 31, 2025.

Summit Midstream Corporation (NYSE: SMC)Exhibit 99.1.

The company states the information under Item 2.02 is being furnished, not filed, under the Exchange Act.

Amendment No. 2 to a Schedule 13D reports that Tailwater-related parties, through Connect Midstream, now beneficially hold 6,670,946 shares of Summit Midstream Corp (SMC), equal to 35.5% of the outstanding common stock on the filing date. The aggregate includes 6,524,467 Common Stock issuable upon conversion of an equivalent number of partnership Common Units and related Class B shares plus 146,479 directly held shares. The filing amends a prior Schedule 13D and notes that recent open-market purchases on 8/26/2025–8/28/2025 totaling 146,479 shares were financed with working capital at average prices of $20.46–$20.89 per share. The document details the ownership chain: Tailwater Energy Fund III LP is sole member of Connect Midstream and identifies the controlling entities and two managing partners who may be deemed to beneficially own the reported securities. The filing is signed 09/02/2025.

Summit Midstream insiders purchased shares: Connect Midstream, LLC acquired 26,319 shares of Summit Midstream Corp (SMC) on 08/28/2025 at a weighted-average price of $20.89 (individual trades ranged from $20.43 to $21.01). After the purchase, Connect Midstream directly holds 146,479 shares. The filing lists related reporting entities and individuals: Tailwater Energy Fund III LP, Tailwater Capital LLC, Jason H. Downie and Edward Herring, each noted as a director and 10% owner or related to the reporting chain. Signatures are dated 09/02/2025.