SMLP / Summit Midstream Partners, LP - Limited Partnership - Depositi SEC, Relazione annuale, dichiarazione di delega

SMLP / Summit Midstream Partners, LP - Limited Partnership / Invesco Ltd. - SEC SCHEDULE 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 6 )* Summit Midstream Partners LP (Name of Issuer) Partnership Interest (Title of Class of Securities) 866142409 (CUSIP Number) August 30, 2024 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant t

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 15 CERTIFICATION AND NOTICE OF TERMINATION OF REGISTRATION UNDER SECTION 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR SUSPENSION OF DUTY TO FILE REPORTS UNDER SECTIONS 13

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 15 CERTIFICATION AND NOTICE OF TERMINATION OF REGISTRATION UNDER SECTION 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR SUSPENSION OF DUTY TO FILE REPORTS UNDER SECTIONS 13 AND 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number: 001-35666 SUMMIT MIDSTREAM PARTNERS, LP (Exact name of registrant as specifi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2024 or o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 00

As filed with the Securities and Exchange Commission on August 9, 2024

As filed with the Securities and Exchange Commission on August 9, 2024 Registration No.

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 8, 2024 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 99-3056990 (State or other jurisdiction (Commission (IRS Employe

Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, Texas 77002

Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, Texas 77002 August 9, 2024 VIA EDGAR U.

As filed with the Securities and Exchange Commission on August 9, 2024

As filed with the Securities and Exchange Commission on August 9, 2024 Registration No.

As filed with the Securities and Exchange Commission on August 9, 2024

As filed with the Securities and Exchange Commission on August 9, 2024 Registration No.

As filed with the Securities and Exchange Commission on August 9, 2024

As filed with the Securities and Exchange Commission on August 9, 2024 Registration No.

Summit Midstream Corporation Reports Second Quarter 2024 Financial and Operating Results of Summit Midstream Partners, LP

EXHIBIT 99.1 Summit Midstream Corporation 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Corporation Reports Second Quarter 2024 Financial and Operating Results of Summit Midstream Partners, LP Houston, Texas (August 8, 2024) – Summit Midstream Corporation (NYSE: SMC) (“Summit”, “SMC” or the “Company”) announced today the financial and operating results of Summit Midstream Par

Fifth Amended and Restated Agreement of Limited Partnership of Summit Midstream Partners, LP, dated August 1, 2024.

Exhibit 3.1 FIFTH AMENDED AND RESTATED AGREEMENT OF LIMITED PARTNERSHIP OF Summit Midstream Partners, LP THIS FIFTH AMENDED AND RESTATED AGREEMENT OF LIMITED PARTNERSHIP (this “Agreement”) of Summit Midstream Partners, LP, a Delaware limited partnership (the “Partnership”), is dated and effective as of August 1, 2024, by and between Summit Midstream GP, LLC, as the general partner of the Partnersh

Third Amended and Restated Limited Liability Company Agreement of Summit Midstream GP, LLC, dated August 1, 2024.

Exhibit 3.2 Execution Version THIRD AMENDED AND RESTATED LIMITED LIABILITY COMPANY AGREEMENT OF SUMMIT MIDSTREAM GP, LLC This Third Amended and Restated Limited Liability Company Agreement (this “Agreement”) of SUMMIT MIDSTREAM GP, LLC, a Delaware limited liability company (the “Company”), is entered into, as of August 1, 2024, by Summit Midstream Partners Holdings, LLC, a Delaware limited liabili

Completion of Acquisition or Disposition of Assets, Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing, Material Modification to Rights of Security Holders, Changes in Control of Registrant, Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 1, 2024 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction of incorporation) (Commi

EX-99.25

NOTIFICATION OF THE REMOVAL FROM LISTING AND REGISTRATION OF THE STATED SECURITIES The New York Stock Exchange hereby notifies the SEC of its intention to remove the entire class of the stated securities from listing and registration on the Exchange at the opening of business on August 12, 2024, pursuant to the provisions of Rule 12d2-2 (a).

Entry into a Material Definitive Agreement, Termination of a Material Definitive Agreement, Financial Statements and Exhibits, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 26, 2024 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission File Number)

Notice and Reaffirmation of Intercreditor Agreement, dated as of July 26, 2024, among Bank of America, N.A., as first lien representative and collateral agent for the initial first lien claimholders, and Regions Bank, as initial second lien representative for the initial second lien claimholders and collateral agent for the initial second lien claimholders, acknowledged and agreed to by the grantors referred to therein.

Exhibit 10.2 NOTICE AND REAFFIRMATION OF INTERCREDITOR AGREEMENT This NOTICE AND REAFFIRMATION OF INTERCREDITOR AGREEMENT (this “Agreement”) is entered into as of July 26, 2024, among BANK OF AMERICA, N.A. (“Bank of America”), as First Lien Representative for the Initial First Lien Claimholders (in such capacity and together with its permitted successors and assigns from time to time in such capac

Amended and Restated Loan and Security Agreement, dated as of July 26, 2024, by and among Summit Midstream Holdings, LLC, as borrower, Summit Midstream Partners, LP, the subsidiary guarantors party thereto from time to time, Bank of America, N.A., as agent, and Bank of America, N.A., Royal Bank of Canada, Regions Capital Markets, TD Securities (USA) LLC, JPMorgan Chase Bank, N.A., Citizens Bank, N.A. and Truist Bank, collectively, as joint lead arrangers and joint bookrunners.

Exhibit 10.1 Execution Version AMENDED AND RESTATED LOAN AND SECURITY AGREEMENT Dated as of July 26, 2024 SUMMIT MIDSTREAM HOLDINGS, LLC, as Borrower and SUMMIT MIDSTREAM PARTNERS, LP and CERTAIN SUBSIDIARIES FROM TIME TO TIME PARTY HERETO, as Guarantors BANK OF AMERICA, N.A., as Agent BANK OF AMERICA, N.A., ROYAL BANK OF CANADA, REGIONS CAPITAL MARKETS, TD SECURITIES (USA) LLC, JPMORGAN CHASE BAN

Indenture, dated July 26, 2024, among Summit Midstream Holdings, LLC, as issuer, the guarantors party thereto and Regions Bank, as trustee and as collateral agent (Incorporated herein by reference to Exhibit 4.1 to SMLP’s Current Report on Form 8-K filed July 29, 2024 (Commission File No. 001-35666)).

Exhibit 4.1 Execution Version SUMMIT MIDSTREAM HOLDINGS, LLC As Issuer, SUMMIT MIDSTREAM PARTNERS, LP, As Parent Guarantor AND THE SUBSIDIARY GUARANTORS NAMED ON THE SIGNATURE PAGES HEREOF 8.625% SENIOR SECURED SECOND LIEN NOTES DUE 2029 INDENTURE Dated as of July 26, 2024 REGIONS BANK As Trustee and Collateral Agent TABLE OF CONTENTS Page ARTICLE 1 DEFINITIONS AND INCORPORATION BY REFERENCE 2 Sec

Financial Statements and Exhibits, Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): July 18, 2024 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission File Number)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): July 18, 2024 Summit Midstream Pa

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): July 18, 2024 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission File Number)

Other Events, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 17, 2024 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Employer

Summit Midstream Partners, LP Announces Proposed Offering of $500 million of Senior Secured Second Lien Notes Due 2029

Exhibit 99.2 Summit Midstream Partners, LP Announces Proposed Offering of $500 million of Senior Secured Second Lien Notes Due 2029 HOUSTON, July 17, 2024 /PRNewswire/ - Summit Midstream Partners, LP (NYSE: SMLP) (“Summit,” “SMLP” or the “Partnership”) announced today that Summit Midstream Holdings, LLC (the “Issuer”), which is a subsidiary of the Partnership, has commenced an offering (the “Offer

Summit Midstream Partners, LP Announces Commencement of a Cash Tender Offer to Purchase Any and All of Its Subsidiaries’ 8.500% Senior Secured Second Lien Notes Due 2026

Exhibit 99.1 Summit Midstream Partners, LP Announces Commencement of a Cash Tender Offer to Purchase Any and All of Its Subsidiaries’ 8.500% Senior Secured Second Lien Notes Due 2026 HOUSTON, July 17, 2024 /PRNewswire/ - Summit Midstream Partners, LP (NYSE: SMLP) (“Summit,” “SMLP” or the “Partnership”) announced today that Summit Midstream Holdings, LLC (“Holdings”) and Summit Midstream Finance Co

Summit Midstream Partners, LP Announces Pricing of Upsized Offering of $575 Million of Senior Secured Second Lien Notes Due 2029

Exhibit 99.1 Summit Midstream Partners, LP Announces Pricing of Upsized Offering of $575 Million of Senior Secured Second Lien Notes Due 2029 HOUSTON, July 17, 2024 /PRNewswire/ - Summit Midstream Partners, LP (NYSE: SMLP) (“Summit,” “SMLP” or the “Partnership”) announced today that Summit Midstream Holdings, LLC, which is a subsidiary of the Partnership, priced an upsized offering (the “Offering”

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 17, 2024 Summit Midstream Pa

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 17, 2024 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission File Number)

Filed by Summit Midstream Partners, LP pursuant to

Filed by Summit Midstream Partners, LP pursuant to Rule 425 under the Securities Act of 1933 and deemed filed pursuant to Rule 14a-12 under the Securities Exchange Act of 1934 Subject Company: Summit Midstream Partners, LP Commission File No. 001-35666 The following document was mailed to Summit Midstream Partners, LP common unitholders on July 8, 2024.

Filed by Summit Midstream Partners, LP pursuant to

Filed by Summit Midstream Partners, LP pursuant to Rule 425 under the Securities Act of 1933 and deemed filed pursuant to Rule 14a-12 under the Securities Exchange Act of 1934 Subject Company: Summit Midstream Partners, LP Commission File No. 001-35666 The following document was mailed to Summit Midstream Partners, LP common unitholders on July 2, 2024.

The reorganization to a C - corporation delivers key benefits to Summit unitholders: June 26, 2024 Maximize the Value of Your Investment Vote “FOR” Reorganization to a C - Corporation Today Summit unitholders have three quick and easy ways to vote “F

Filed by Summit Midstream Partners, LP pursuant to Rule 425 under the Securities Act of 1933 and deemed filed pursuant to Rule 14a-12 under the Securities Exchange Act of 1934 Subject Company: Summit Midstream Partners, LP Commission File No.

Termination of a Material Definitive Agreement, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 24, 2024 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Employer

As filed with the Securities and Exchange Commission on June 21, 2024

S-8 1 forms-8june2024.htm S-8 As filed with the Securities and Exchange Commission on June 21, 2024 Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-8 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 SUMMIT MIDSTREAM PARTNERS, LP (Exact name of registrant as specified in its charter) Delaware 45-5200503 (State or other jurisdiction of inco

Filing Fee Table.

Exhibit 107 Calculation of Filing Fee Tables Form S-8 (Form Type) Summit Midstream Partners, LP (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities Security Type Security Class Title Fee Calculation Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Equity Common Units representing limited partner interests Other(1) 750,000(2) $31.

1 C - Corporation Conversion Delivers Key Benefits to Unitholders Conversion method is a unitholder friendly transaction requiring a unitholder vote 1 Increases trading liquidity and expands potential investor pool Simplifies Summit’s tax reporting s

Exhibit 99.2 1 C - Corporation Conversion Delivers Key Benefits to Unitholders Conversion method is a unitholder friendly transaction requiring a unitholder vote 1 Increases trading liquidity and expands potential investor pool Simplifies Summit’s tax reporting structure making the equity much easier to own Reduces unitholder’s tax burden going forward, including by eliminating recapture of previo

Summit Advances Planned Conversion to C-Corporation to Facilitate Growth and Value Creation Schedules July 18th Special Meeting for Unitholder Approval: Recommends Common Unitholders Vote “FOR” C-Corporation Conversion Files Investor Presentation, Ou

Exhibit 99.1 Summit Advances Planned Conversion to C-Corporation to Facilitate Growth and Value Creation Schedules July 18th Special Meeting for Unitholder Approval: Recommends Common Unitholders Vote “FOR” C-Corporation Conversion Files Investor Presentation, Outlining Benefits for Summit Unitholders HOUSTON, June 17, 2024 – Summit Midstream Partners, LP (NYSE: SMLP) (“Summit,” “SMLP” or the “Par

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 17, 2024 Summit Midstream Pa

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 17, 2024 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission File Number)

DEAR SUMMIT UNITHOLDER, Over the past year, the Summit Board and leadership team have successfully repositioned our company in key oil and gas markets while strengthening our financial profile. Today, Summit has a franchise gathering and processing p

Exhibit 99.3 DEAR SUMMIT UNITHOLDER, Over the past year, the Summit Board and leadership team have successfully repositioned our company in key oil and gas markets while strengthening our financial profile. Today, Summit has a franchise gathering and processing position in the Williston and DJ Basins, and a premier long - haul pipeline servicing the Permian Basin. We are proud of the progress we h

DEAR SUMMIT UNITHOLDER, Over the past year, the Summit Board and leadership team have successfully repositioned our company in key oil and gas markets while strengthening our financial profile. Today, Summit has a franchise gathering and processing p

Exhibit 99.3 DEAR SUMMIT UNITHOLDER, Over the past year, the Summit Board and leadership team have successfully repositioned our company in key oil and gas markets while strengthening our financial profile. Today, Summit has a franchise gathering and processing position in the Williston and DJ Basins, and a premier long - haul pipeline servicing the Permian Basin. We are proud of the progress we h

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 17, 2024 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission File Number)

1 C - Corporation Conversion Delivers Key Benefits to Unitholders Conversion method is a unitholder friendly transaction requiring a unitholder vote 1 Increases trading liquidity and expands potential investor pool Simplifies Summit’s tax reporting s

Exhibit 99.2 1 C - Corporation Conversion Delivers Key Benefits to Unitholders Conversion method is a unitholder friendly transaction requiring a unitholder vote 1 Increases trading liquidity and expands potential investor pool Simplifies Summit’s tax reporting structure making the equity much easier to own Reduces unitholder’s tax burden going forward, including by eliminating recapture of previo

Summit Advances Planned Conversion to C-Corporation to Facilitate Growth and Value Creation Schedules July 18th Special Meeting for Unitholder Approval: Recommends Common Unitholders Vote “FOR” C-Corporation Conversion Files Investor Presentation, Ou

Exhibit 99.1 Summit Advances Planned Conversion to C-Corporation to Facilitate Growth and Value Creation Schedules July 18th Special Meeting for Unitholder Approval: Recommends Common Unitholders Vote “FOR” C-Corporation Conversion Files Investor Presentation, Outlining Benefits for Summit Unitholders HOUSTON, June 17, 2024 – Summit Midstream Partners, LP (NYSE: SMLP) (“Summit,” “SMLP” or the “Par

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☒ Defin

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 7, 2024 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Employer

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 6, 2024 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Employer

Summit Midstream Partners, LP Announces Expiration and Results for Asset Sale Offer to Purchase up to $215,000,000 Aggregate Principal Amount of Outstanding 8.500% Senior Secured Second Lien Notes Due 2026

EXHIBIT 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Announces Expiration and Results for Asset Sale Offer to Purchase up to $215,000,000 Aggregate Principal Amount of Outstanding 8.500% Senior Secured Second Lien Notes Due 2026 HOUSTON, June 6, 2024 - Summit Midstream Partners, LP (NYSE: SMLP) (“Summit,” “SMLP” or the “Partner

RISK FACTORS

Exhibit 99.1 RISK FACTORS References herein to “this proxy statement/prospectus” are to the proxy statement/prospectus contained in the registration statement on Form S-4 initially filed with the Securities and Exchange Commission by Summit Midstream Corporation (“New Summit”) on May 31, 2024. Realization of any of the risks described below could have a material adverse effect on Summit Midstream

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 31, 2024 Summit Midstream Par

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 31, 2024 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission File Number) (

Agreement and Plan of Merger, dated as of May 31, 2024, by and among Summit Midstream Corporation, Summit SMC NewCo, LLC, Summit Midstream Partners, LP and Summit Midstream GP, LLC (Incorporated herein by reference to Exhibit 2.1 to SMLP’s Current Report on Form 8-K filed June 3, 2024 (Commission File No. 001-35666))

Exhibit 2.1 AGREEMENT AND PLAN OF MERGER DATED AS OF MAY 31, 2024 BY AND AMONG SUMMIT MIDSTREAM CORPORATION, SUMMIT SMC NEWCO, LLC, Summit Midstream Partners, LP, AND SUMMIT MIDSTREAM GP, LLC Table of Contents Page Article I DEFINITIONS 1 Section 1.01 Definitions 1 Article II The Merger 6 Section 2.01 The Merger and Surviving Entity 6 Section 2.02 Closing 6 Section 2.03 Effective Time 6 Section 2.

Agreement and Plan of Merger, dated as of May 31, 2024, by and among Summit Midstream Corporation, Summit SMC NewCo, LLC, Summit Midstream Partners, LP and Summit Midstream GP, LLC.

Exhibit 2.1 AGREEMENT AND PLAN OF MERGER DATED AS OF MAY 31, 2024 BY AND AMONG SUMMIT MIDSTREAM CORPORATION, SUMMIT SMC NEWCO, LLC, Summit Midstream Partners, LP, AND SUMMIT MIDSTREAM GP, LLC Table of Contents Page Article I DEFINITIONS 1 Section 1.01 Definitions 1 Article II The Merger 6 Section 2.01 The Merger and Surviving Entity 6 Section 2.02 Closing 6 Section 2.03 Effective Time 6 Section 2.

Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 31, 2024 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission File Number) (

RISK FACTORS

Exhibit 99.1 RISK FACTORS References herein to “this proxy statement/prospectus” are to the proxy statement/prospectus contained in the registration statement on Form S-4 initially filed with the Securities and Exchange Commission by Summit Midstream Corporation (“New Summit”) on May 31, 2024. Realization of any of the risks described below could have a material adverse effect on Summit Midstream

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 16, 2024 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Employer

First Amendment to the Summit Midstream Partners, LP 2022 Long-Term Incentive Plan (Incorporated herein by reference to Exhibit 10.1 to SMLP’s Current Report on Form 8-K filed May 22, 2024 (Commission File No. 001-35666))

Exhibit 10.1 FIRST AMENDMENT TO THE SUMMIT MIDSTREAM PARTNERS, LP 2022 LONG-TERM INCENTIVE PLAN THIS FIRST AMENDMENT (this “Amendment”) to the Summit Midstream Partners, LP 2022 Long-Term Incentive Plan, effective as of March 16, 2022 (the “Plan”), is effective May 16, 2024 (the “Effective Date”). WHEREAS, Summit Midstream GP, LLC, a Delaware limited liability company (the “Company”), the general

Financial Statements and Exhibits, Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 9, 2024 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Employer o

Summit Midstream Partners, LP Announces Asset Sale Offer to Purchase up to $215,000,000 Aggregate Principal Amount of Outstanding 8.500% Senior Secured Second Lien Notes Due 2026

EXHIBIT 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Announces Asset Sale Offer to Purchase up to $215,000,000 Aggregate Principal Amount of Outstanding 8.500% Senior Secured Second Lien Notes Due 2026 HOUSTON, May 7, 2024 /PRNewswire/ - Summit Midstream Partners, LP (NYSE: SMLP) (“Summit,” “SMLP” or the “Partnership”) today an

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 7, 2024 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Employer o

The unaudited pro forma condensed consolidated balance sheet as of March 31, 2024 and the unaudited pro forma condensed consolidated statements of operations for the year ended December 31, 2023 and the three-months ended March 31, 2024

EXHIBIT 99.1 SUMMIT MIDSTREAM PARTNERS, LP AND SUBSIDIARIES PRO FORMA CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Unaudited) March 2024 disposition of Summit Midstream Utica, LLC On March 22, 2024, Summit Midstream Partners, LP (“Summit” and, together with its subsidiaries, “SMLP” or the “Partnership”), and Summit Midstream OpCo, LP, an indirectly owned subsidiary of Summit (“OpCo”), completed th

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2024 or o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 0

Summit Midstream Partners, LP Subsidiary Issuers and Guarantors of Registered Securities

EXHIBIT 22.1 SUMMIT MIDSTREAM PARTNERS, LP SUBSIDIARY ISSUERS AND GUARANTORS OF REGISTERED SECURITIES The below chart lists the subsidiary co-issuers and guarantors of the 5.75% senior notes due 2025 (the “Senior Notes”). Subsidiary Registered Security Guarantor Status Summit Midstream Holdings, LLC Senior Notes Co-Issuer, Not a guarantor Summit Midstream Finance Corp. Senior Notes Co-Issuer, Not

Purchase and Sale Agreement, dated May 1, 2024, by and among Mountaineer Midstream Company, LLC, as Seller, and Antero Midstream LLC, as Buyer, and for the limited purposes expressly set forth thereto, Summit Midstream Partners, LP (Incorporated herein by reference to Exhibit 10.1 to Summit Midstream Partners, LP’s Quarterly Report on Form 10-Q filed May 6, 2024 (Commission File No. 001-35666)).

Execution Version PURCHASE AND SALE AGREEMENT by and among MOUNTAINEER MIDSTREAM COMPANY, LLC, as Seller, and ANTERO MIDSTREAM LLC, as Buyer, and FOR THE LIMITED PURPOSES EXPRESSLY SET FORTH HEREIN, SUMMIT MIDSTREAM PARTNERS, LP, AND SUMMIT MIDSTREAM HOLDINGS, LLC ii TABLE OF CONTENTS Page ARTICLE I DEFINITIONS AND INTERPRETATION 1.

Summit Midstream Partners, LP Reports First Quarter 2024 Financial and Operating Results

EXHIBIT 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Reports First Quarter 2024 Financial and Operating Results Houston, Texas (May 2, 2024) – Summit Midstream Partners, LP (NYSE: SMLP) (“Summit”, “SMLP” or the “Partnership”) announced today its financial and operating results for the three months ended March 31, 2024. Highligh

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 2, 2024 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Employer o

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐Preliminary Proxy Statement ☐Confidential, for use of the Commission only (as permitted by Rule 14a-6(e)(2)) ☐Definiti

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐Preliminary Proxy Statement ☐Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☒Definitive Proxy Statemen

Purchase and Sale Agreement, dated as of March 22, 2024, by and among Summit Midstream Opco, LP, as Seller, MPLX LP, as Buyer, and, solely for purposes of Section 12.18 thereto, Summit Midstream Partners, LP, as Seller Parent.

Execution Version PURCHASE AND SALE AGREEMENT BY AND AMONG SUMMIT MIDSTREAM OPCO, LP, as Seller, MARKWEST UTICA OPERATING COMPANY, L.

Summit Midstream Partners, LP Announces Sale of Utica Position for $625 Million Concludes Strategic Alternatives Process; Plans to Seek Approval from Unitholders to Convert to a C-Corp

EXHIBIT 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Announces Sale of Utica Position for $625 Million Concludes Strategic Alternatives Process; Plans to Seek Approval from Unitholders to Convert to a C-Corp HOUSTON, (March 22, 2024) – Summit Midstream Partners, LP (NYSE: SMLP) (“Summit”, “SMLP” or the “Partnership”) announced

SUMMIT MIDSTREAM PARTNERS, LP AND SUBSIDIARIES PRO FORMA CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Unaudited)

EXHIBIT 99.2 SUMMIT MIDSTREAM PARTNERS, LP AND SUBSIDIARIES PRO FORMA CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Unaudited) March 2024 disposition of Summit Midstream Utica, LLC On March 22, 2024, Summit Midstream Partners, LP (“Summit” and, together with its subsidiaries, “SMLP” or the “Partnership”), and Summit Midstream OpCo, LP, an indirectly owned subsidiary of Summit (“OpCo”), completed th

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K/A (Amendment No. 1) CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): March 22, 202

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K/A (Amendment No. 1) CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): March 22, 2024 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Com

Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Completion of Acquisition or Disposition of Assets, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K/A (Amendment No. 1) CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): March 22, 2024 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Com

Fourth Amendment to Loan and Security Agreement, dated as of March 22, 2024, by and among Summit Midstream Partners, LP, Summit Midstream Holdings, LLC, the subsidiaries of Holdings party thereto, the lenders party thereto and Bank of America, N.A., as agent for such lenders.

Execution Version 1 FOURTH AMENDMENT TO LOAN AND SECURITY AGREEMENT This FOURTH AMENDMENT TO LOAN AND SECURITY AGREEMENT (this “Fourth Amendment”) is dated as of March 22, 2024 (the “Fourth Amendment Effective Date”), among SUMMIT MIDSTREAM PARTNERS, LP, a Delaware limited partnership (the “MLP Entity”), SUMMIT MIDSTREAM HOLDINGS, LLC, a Delaware limited liability company (“Borrower”), the Subsidiary Guarantors (as defined in the Loan Agreement referred to below), the Lenders (as defined in the Loan Agreement) party hereto and BANK OF AMERICA, N.

Fourth Amendment to Loan and Security Agreement, dated as of March 22, 2024, by and among Summit Midstream Partners, LP, Summit Midstream Holdings, LLC, the subsidiaries of Holdings party thereto, the lenders party thereto and Bank of America, N.A., as agent for such lenders.

Execution Version 1 FOURTH AMENDMENT TO LOAN AND SECURITY AGREEMENT This FOURTH AMENDMENT TO LOAN AND SECURITY AGREEMENT (this “Fourth Amendment”) is dated as of March 22, 2024 (the “Fourth Amendment Effective Date”), among SUMMIT MIDSTREAM PARTNERS, LP, a Delaware limited partnership (the “MLP Entity”), SUMMIT MIDSTREAM HOLDINGS, LLC, a Delaware limited liability company (“Borrower”), the Subsidiary Guarantors (as defined in the Loan Agreement referred to below), the Lenders (as defined in the Loan Agreement) party hereto and BANK OF AMERICA, N.

Purchase and Sale Agreement, dated as of March 22, 2024, by and among Summit Midstream Opco, LP, as Seller, MPLX LP, as Buyer, and, solely for purposes of Section 12.18 thereto, Summit Midstream Partners, LP, as Seller Parent.

Execution Version PURCHASE AND SALE AGREEMENT BY AND AMONG SUMMIT MIDSTREAM OPCO, LP, as Seller, MARKWEST UTICA OPERATING COMPANY, L.

Summit Midstream Partners, LP Announces Sale of Utica Position for $625 Million Concludes Strategic Alternatives Process; Plans to Seek Approval from Unitholders to Convert to a C-Corp

EXHIBIT 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Announces Sale of Utica Position for $625 Million Concludes Strategic Alternatives Process; Plans to Seek Approval from Unitholders to Convert to a C-Corp HOUSTON, (March 22, 2024) – Summit Midstream Partners, LP (NYSE: SMLP) (“Summit”, “SMLP” or the “Partnership”) announced

SUMMIT MIDSTREAM PARTNERS, LP AND SUBSIDIARIES PRO FORMA CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Unaudited)

EXHIBIT 99.2 SUMMIT MIDSTREAM PARTNERS, LP AND SUBSIDIARIES PRO FORMA CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Unaudited) March 2024 disposition of Summit Midstream Utica, LLC On March 22, 2024, Summit Midstream Partners, LP (“Summit” and, together with its subsidiaries, “SMLP” or the “Partnership”), and Summit Midstream OpCo, LP, an indirectly owned subsidiary of Summit (“OpCo”), completed th

Summit Midstream Partners, LP Announces Excess Cash Flow Offer to Purchase up to $19,331,000 Aggregate Principal Amount of Outstanding 8.500% Senior Secured Second Lien Notes Due 2026

EXHIBIT 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Announces Excess Cash Flow Offer to Purchase up to $19,331,000 Aggregate Principal Amount of Outstanding 8.500% Senior Secured Second Lien Notes Due 2026 HOUSTON, March 27, 2024 /PRNewswire/ - Summit Midstream Partners, LP (NYSE: SMLP) (“Summit,” “SMLP” or the “Partnership”)

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 27, 2024 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Employe

SMLP / Summit Midstream Partners, LP - Limited Partnership / He Zhengxu Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 SCHEDULE 13G/A UNDER THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No.

Fourth Amendment to Loan and Security Agreement, dated as of March 22, 2024, by and among Summit Midstream Partners, LP, Summit Midstream Holdings, LLC, the subsidiaries of Holdings party thereto, the lenders party thereto and Bank of America, N.A., as agent for such lenders (Incorporated herein by reference to Exhibit 10.1 to Summit Midstream Partners, LP’s Current Report on Form 8-K filed March 12, 2024 (Commission File No. 001-35666)).

Execution Version 1 FOURTH AMENDMENT TO LOAN AND SECURITY AGREEMENT This FOURTH AMENDMENT TO LOAN AND SECURITY AGREEMENT (this “Fourth Amendment”) is dated as of March 22, 2024 (the “Fourth Amendment Effective Date”), among SUMMIT MIDSTREAM PARTNERS, LP, a Delaware limited partnership (the “MLP Entity”), SUMMIT MIDSTREAM HOLDINGS, LLC, a Delaware limited liability company (“Borrower”), the Subsidiary Guarantors (as defined in the Loan Agreement referred to below), the Lenders (as defined in the Loan Agreement) party hereto and BANK OF AMERICA, N.

Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Completion of Acquisition or Disposition of Assets, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 22, 2024 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Employe

Fourth Amendment to Loan and Security Agreement, dated as of March 22, 2024, by and among Summit Midstream Partners, LP, Summit Midstream Holdings, LLC, the subsidiaries of Holdings party thereto, the lenders party thereto and Bank of America, N.A., as agent for such lenders.

Execution Version 1 FOURTH AMENDMENT TO LOAN AND SECURITY AGREEMENT This FOURTH AMENDMENT TO LOAN AND SECURITY AGREEMENT (this “Fourth Amendment”) is dated as of March 22, 2024 (the “Fourth Amendment Effective Date”), among SUMMIT MIDSTREAM PARTNERS, LP, a Delaware limited partnership (the “MLP Entity”), SUMMIT MIDSTREAM HOLDINGS, LLC, a Delaware limited liability company (“Borrower”), the Subsidiary Guarantors (as defined in the Loan Agreement referred to below), the Lenders (as defined in the Loan Agreement) party hereto and BANK OF AMERICA, N.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 22, 2024 Summit Midstream P

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 22, 2024 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Employe

Purchase and Sale Agreement, dated as of March 22, 2024, by and among Summit Midstream Opco, LP, as Seller, MPLX LP, as Buyer, and, solely for purposes of Section 12.18 thereto, Summit Midstream Partners, LP, as Seller Parent.

Execution Version PURCHASE AND SALE AGREEMENT BY AND AMONG SUMMIT MIDSTREAM OPCO, LP, as Seller, MARKWEST UTICA OPERATING COMPANY, L.

Summit Midstream Partners, LP Announces Sale of Utica Position for $625 Million Concludes Strategic Alternatives Process; Plans to Seek Approval from Unitholders to Convert to a C-Corp

EXHIBIT 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Announces Sale of Utica Position for $625 Million Concludes Strategic Alternatives Process; Plans to Seek Approval from Unitholders to Convert to a C-Corp HOUSTON, (March 22, 2024) – Summit Midstream Partners, LP (NYSE: SMLP) (“Summit”, “SMLP” or the “Partnership”) announced

Purchase and Sale Agreement, dated as of March 22, 2024, by and among Summit Midstream Opco, LP, as Seller, MPLX LP, as Buyer, and, solely for purposes of Section 12.18 thereto, Summit Midstream Partners, LP, as Seller Parent (Incorporated herein by reference to Exhibit 2.1 to Summit Midstream Partners, LP’s Current Report on Form 8-K filed March 12, 2024 (Commission File No. 001-35666)).

Execution Version PURCHASE AND SALE AGREEMENT BY AND AMONG SUMMIT MIDSTREAM OPCO, LP, as Seller, MARKWEST UTICA OPERATING COMPANY, L.

Summit Midstream Partners, LP Announces Sale of Utica Position for $625 Million Concludes Strategic Alternatives Process; Plans to Seek Approval from Unitholders to Convert to a C-Corp

EXHIBIT 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Announces Sale of Utica Position for $625 Million Concludes Strategic Alternatives Process; Plans to Seek Approval from Unitholders to Convert to a C-Corp HOUSTON, (March 22, 2024) – Summit Midstream Partners, LP (NYSE: SMLP) (“Summit”, “SMLP” or the “Partnership”) announced

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-K x ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 or o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-35666 Summit Midstream Partners

Summit Midstream Partners, LP Subsidiary Issuers and Guarantors of Registered Securities

exhibit-221subsidiaryis EXHIBIT 22.1 Subsidiary Registered Security Guarantor Status Summit Midstream Holdings, LLC Senior Notes Co-Issuer, Not a guarantor Summit Midstream Finance Corp. Senior Notes Co-Issuer, Not a guarantor Summit Midstream Partners, LP Senior Notes Joint and Several, Fully and Unconditionally Grand River Gathering, LLC Senior Notes Joint and Several, Fully and Unconditionally

Summit Midstream Partners, LP Reports Fourth Quarter and Full-Year 2023 Financial and Operating Results, 2024 Guidance and Strategic Alternatives Update

EXHIBIT 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Reports Fourth Quarter and Full-Year 2023 Financial and Operating Results, 2024 Guidance and Strategic Alternatives Update Houston, Texas (March 15, 2024) – Summit Midstream Partners, LP (NYSE: SMLP) (“Summit”, “SMLP” or the “Partnership”) announced today its financial and op

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 15, 2024 Summit Midstream P

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 15, 2024 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Employe

List of Subsidiaries

exhibit-211listofsubsid EXHIBIT 21.1 Name State or other jurisdiction of incorporation or organization DFW Midstream Services LLC Delaware Centennial Water Pipelines LLC Delaware Double E Pipeline, LLC Delaware Epping Transmission Company, LLC Delaware Grand River Gathering, LLC Delaware Grasslands Energy Marketing LLC Delaware Meadowlark Midstream Company, LLC Delaware Mountaineer Midstream Compa

Summit Midstream Partners, LP Policy for the Recovery of Erroneously Awarded

SUMMIT MIDSTREAM PARTNERS, LP POLICY FOR THE RECOVERY OF ERRONEOUSLY AWARDED COMPENSATION 1.

SMLP / Summit Midstream Partners, LP - Limited Partnership / SHENKMAN CAPITAL MANAGEMENT INC - SUMMIT MIDSTREAM PARTNERS, LP Passive Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 1)* Summit Midstream Partners, LP (Name of Issuer) Common Units (Title of Class of Securities) 866142409 (CUSIP Number) December 31, 2023 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Sched

SMLP / Summit Midstream Partners, LP - Limited Partnership / Invesco Ltd. - SEC SCHEDULE 13G Passive Investment

SC 13G/A 1 SEC13GFiling.htm SEC SCHEDULE 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 5 )* Summit Midstream Partners LP (Name of Issuer) Partnership Interest (Title of Class of Securities) 866142409 (CUSIP Number) December 29, 2023 (Date of Event Which Requires Filing of this Statement) Check the a

Indenture, dated as of November 21, 2023, by and among Summit Midstream Holdings, LLC, Summit Midstream Finance Corp., the Guarantors party thereto and Regions Bank, as trustee (including form of the 12.00% Senior Unsecured Notes due 2026) (Incorporated herein by reference to Exhibit 4.1 to Summit Midstream Partners, LP’s Current Report on Form 8-K filed November 22, 2023 (Commission File No. 001-35666)).

107920296 Execution Version SUMMIT MIDSTREAM HOLDINGS, LLC SUMMIT MIDSTREAM FINANCE CORP.

Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): November 16, 2023 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Empl

Third Amendment to Loan and Security Agreement, dated November 21, 2023, among Summit Midstream Partners, LP, Summit Midstream Holdings, LLC, the lenders party thereto and Bank of America, N.A., as agent for such lenders (Incorporated herein by reference to Exhibit 10.1 to Summit Midstream Partners, LP’s Current Report on Form 8-K filed November 22, 2023 (Commission File No. 001-35666)).

Execution Version 1 THIRD AMENDMENT TO LOAN AND SECURITY AGREEMENT THIS THIRD AMENDMENT TO LOAN AND SECURITY AGREEMENT (this “Third Amendment”) is dated as of November 21, 2023 (the “Third Amendment Effective Date”), among SUMMIT MIDSTREAM PARTNERS, LP, a Delaware limited partnership (the “MLP Entity”), SUMMIT MIDSTREAM HOLDINGS, LLC, a Delaware limited liability company (“Borrower”), the Subsidiary Guarantors (as defined in the Loan Agreement referred to below), the Lenders (as defined in the Loan Agreement) party hereto and BANK OF AMERICA, N.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 or o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file numbe

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 3, 2023 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Emplo

Summit Midstream Partners, LP Reports Third Quarter 2023 Financial and Operating Results

EXHIBIT 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Reports Third Quarter 2023 Financial and Operating Results Houston, Texas (November 3, 2023) – Summit Midstream Partners, LP (NYSE: SMLP) (“Summit”, “SMLP” or the “Partnership”) announced today its financial and operating results for the three months ended September 30, 2023.

Summit Midstream Partners, LP Provides Operational Update, Announces Review of Strategic Alternatives and Schedules Third Quarter 2023 Earnings Call

EXHIBIT 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Provides Operational Update, Announces Review of Strategic Alternatives and Schedules Third Quarter 2023 Earnings Call Houston, Texas (October 3, 2023) – Summit Midstream Partners, LP (NYSE: SMLP) (“Summit”, “SMLP” or the “Partnership”) announced today an operational update f

Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 3, 2023 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Employ

Summit Midstream Partners, LP Reports Second Quarter 2023 Financial and Operating Results

EXHIBIT 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Reports Second Quarter 2023 Financial and Operating Results Houston, Texas (August 9, 2023) – Summit Midstream Partners, LP (NYSE: SMLP) (“Summit”, “SMLP” or the “Partnership”) announced today its financial and operating results for the three months ended June 30, 2023. Highl

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 9, 2023 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Employe

Omnibus Amendment, dated June 27, 2023, by and among Summit Permian Transmission, LLC, MUFG Bank, Ltd., Mizuho Bank (USA), Mizuho Bank, Ltd. and the lenders party thereto (Incorporated herein by Incorporated herein by reference to Exhibit 10.3 to Summit Midstream Partners, LP’s Quarterly Report on Form 10-Q filed August 9, 2023 (Commission File No. 001-35666)).

Execution Version 1 US-DOCS\141306805.6 OMNIBUS AMENDMENT This Omnibus Amendment, dated as of June 27, 2023 (this “Amendment”), is entered into by and among Summit Permian Transmission, LLC, a Delaware limited liability company (“Borrower”), MUFG Bank, Ltd., as administrative agent (in such capacity, the “Administrative Agent”), Mizuho Bank (USA), as collateral agent (in such capacity, the “Collat

First Amendment to Loan and Security Agreement, dated October 14, 2022, by and among Summit

smlp-firstamendmenttoloa Execution Version US 9324286 1 US 9329301v.2 FIRST AMENDMENT TO LOAN AND SECURITY AGREEMENT THIS FIRST AMENDMENT TO LOAN AND SECURITY AGREEMENT (this “First Amendment”) is dated as of October 14, 2022 (the “First Amendment Effective Date”), among SUMMIT MIDSTREAM PARTNERS, LP, a Delaware limited partnership (the “MLP Entity”), SUMMIT MIDSTREAM HOLDINGS, LLC, a Delaware lim

Second Amendment to Loan and Security Agreement, dated May 10, 2023, by and among Summit Midstream Partners, LP, Summit Midstream Holdings, LLC and Bank of America, N.A. (Incorporated herein by Incorporated herein by reference to Exhibit 10.2 to Summit Midstream Partners, LP’s Quarterly Report on Form 10-Q filed August 9, 2023 (Commission File No. 001-35666)).

Execution Version 1 4856-7282-0833v.2 SECOND AMENDMENT TO LOAN AND SECURITY AGREEMENT THIS SECOND AMENDMENT TO LOAN AND SECURITY AGREEMENT (this “Second Amendment”) is dated as of May 10, 2023 (the “Second Amendment Effective Date”), among SUMMIT MIDSTREAM PARTNERS, LP, a Delaware limited partnership (the “MLP Entity”), SUMMIT MIDSTREAM HOLDINGS, LLC, a Delaware limited liability company (“Borrowe

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 or o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 00

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): May 10, 2023 Summit Midstream Par

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): May 10, 2023 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Employer

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2023 or o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 0

Summit Midstream Partners, LP Reports First Quarter 2023 Financial and Operating Results

EXHIBIT 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Reports First Quarter 2023 Financial and Operating Results Houston, Texas (May 5, 2023) – Summit Midstream Partners, LP (NYSE: SMLP) (“Summit”, “SMLP” or the “Partnership”) announced today its financial and operating results for the three months ended March 31, 2023. Highligh

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 5, 2023 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Employer o

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

smp-def14a051023 UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐Preliminary Proxy Statement ☐Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☒Definiti

Amended and Restated Employment Agreement, effective as of February 23, 2023, by and between Summit Operating Services Company, LLC and James Johnston (Incorporated herein by reference to Exhibit 10.60 to Summit Midstream Partners, LP’s Annual Report on Form 10-K filed March 1, 2023 (Commission File No. 001-35666)).

EXHIBIT 10.60 Amended and Restated Employment Agreement This Amended and Restated Employment Agreement (the “Agreement”), effective February 23, 2023, (the “Effective Date”), is made by and between James Johnston (the “Executive”) and Summit Operating Services Company, LLC (together with any of its subsidiaries and affiliates as may employ the Executive from time to time, and any successor(s) ther

Summit Midstream Partners, LP 2022 Long-Term Incentive Plan 2023 LTIP Grant Award Agreement for Performance-based Phantom Units, effective as of February 23, 2023 (Incorporated herein by reference to Exhibit 10.62 to Summit Midstream Partners, LP’s Annual Report on Form 10-K filed March 1, 2023 (Commission File No. 001-35666)).

smlp-formofperformancexb EXHIBIT 10.62 SUMMIT MIDSTREAM PARTNERS, LP 2022 LONG-TERM INCENTIVE PLAN 2023 LTIP GRANT AWARD AGREEMENT (Performance-based Phantom Units) Pursuant to this 2023 LTIP Grant Award Agreement, dated as of March [ ], 2023 (inclusive of the Grant Notice, Terms and Conditions of the 2023 LTIP Grant and Exhibit A attached hereto, this “Agreement”) and the Summit Midstream Partner

List of Subsidiaries

exhibit-211listofsubsidi EXHIBIT 21.1 Name State or other jurisdiction of incorporation or organization Centennial Water Pipelines LLC Delaware DFW Midstream Services LLC Delaware Epping Transmission Company, LLC Delaware Grand River Gathering, LLC Delaware Grasslands Energy Marketing LLC Delaware Meadowlark Midstream Company, LLC Delaware Mountaineer Midstream Company, LLC Delaware Polar Midstrea

Membership Interest Purchase and Sale Agreement between Summit Midstream Holdings, LLC, Outrigger Energy II LLC and Outrigger DJ Midstream LLC, dated October 14, 2022 (Incorporated herein by reference to Exhibit 2.4 to Summit Midstream Partners, LP’s Annual Report on Form 10-K filed March 1, 2023 (Commission File No. 001-35666)).

membershipinterestpurcha Execution Version MEMBERSHIP INTEREST PURCHASE AND SALE AGREEMENT dated October 14, 2022, by and among SUMMIT MIDSTREAM HOLDINGS, LLC, OUTRIGGER ENERGY II LLC and OUTRIGGER DJ MIDSTREAM LLC i TABLE OF CONTENTS Page ARTICLE 1 DEFINITIONS AND RULES OF CONSTRUCTION .

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-K x ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 or o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934For the transition period from to Commission file number: 001-35666 Summit Midstream Partners,

Amended and Restated Employment Agreement, effective as of February 23, 2023, by and between Summit Operating Services Company, LLC and Heath Deneke (Incorporated herein by reference to Exhibit 10.58 to Summit Midstream Partners, LP’s Annual Report on Form 10-K filed March 1, 2023 (Commission File No. 001-35666)).

EXHIBIT 10.58 Amended and Restated Employment Agreement This Amended and Restated Employment Agreement (the “Agreement”), effective February 23, 2023 (the “Effective Date”), is made by and between Heath Deneke (the “Executive”) and Summit Operating Services Company, LLC (together with any of its subsidiaries and affiliates as may employ the Executive from time to time, and any successor(s) thereto

Form of Summit Midstream Partners, LP 2012 Long-Term Incentive Plan Grant Award Agreement (Incorporated herein by reference to Exhibit 10.54 to SMLP’s Annual Report on Form 10-K filed February 28, 2022 (Commission File No. 001-35666))

EXHIBIT 10.53 February 24, 2022 SUMMIT MIDSTREAM PARTNERS, LP 2012 LONG-TERM INCENTIVE PLAN LTIP GRANT AWARD AGREEMENT Pursuant to this LTIP Grant Award Agreement, dated as of (this “Agreement”) and the Summit Midstream Partners, LP 2012 Long-Term Incentive Plan, as amended and restated (the “Plan”), Summit Midstream GP, LLC (the “Company”), as the general partner of Summit Midstream Partners, LP

Form of Summit Midstream Partners, LP 2022 Long-Term Incentive Plan Director Unit Agreement (Incorporated herein by reference to Exhibit 10.65 to Summit Midstream Partners, LP’s Annual Report on Form 10-K filed March 1, 2023 (Commission File No. 001-35666)).

EXHIBIT 10.65 SUMMIT MIDSTREAM PARTNERS, LP 2022 LONG-TERM INCENTIVE PLAN DIRECTOR UNIT AGREEMENT Pursuant to this Director Unit Agreement, dated as of [ ] (this “Agreement”), Summit Midstream GP, LLC (the “Company”), as the general partner of Summit Midstream Partners, LP (the “Partnership”), hereby grants to [ ] (the “Participant”) the following Unit Award pursuant and subject to the terms and c

Amended and Restated Employment Agreement, effective as of February 23, 2023, by and between Summit Operating Services Company, LLC and William (Bill) Mault (Incorporated herein by reference to Exhibit 10.59 to Summit Midstream Partners, LP’s Annual Report on Form 10-K filed March 1, 2023 (Commission File No. 001-35666)).

EXHIBIT 10.59 Amended and Restated Employment Agreement This Amended and Restated Employment Agreement (the “Agreement”), effective February 23, 2023 (the “Effective Date”), is made by and between William (Bill) Mault (the “Executive”) and Summit Operating Services Company, LLC (together with any of its subsidiaries and affiliates as may employ the Executive from time to time, and any successor(s)

Purchase and Sale Agreement between Summit Midstream Holdings, LLC and Sterling Investment Holdings, dated October 14, 2022 (Incorporated herein by reference to Exhibit 2.5 to Summit Midstream Partners, LP’s Annual Report on Form 10-K filed March 1, 2023 (Commission File No. 001-35666)).

summitpurchaseandsaleagr Execution Version PURCHASE AND SALE AGREEMENT BY AND BETWEEN STERLING INVESTMENT HOLDINGS LLC, as Seller, AND SUMMIT MIDSTREAM HOLDINGS, LLC, as Buyer October 14, 2022 i TABLE OF CONTENTS Page ARTICLE I DEFINITIONS AND INTERPRETATIONS.

Form of Summit Midstream Partners, LP 2023 Long-Term Incentive Plan Director Unit Agreement (Incorporated herein by reference to Exhibit 10.66 to Summit Midstream Partners, LP’s Annual Report on Form 10-K filed March 1, 2023 (Commission File No. 001-35666)).

EXHIBIT 10.66 SUMMIT MIDSTREAM PARTNERS, LP 2022 LONG-TERM INCENTIVE PLAN DIRECTOR UNIT AGREEMENT Pursuant to this Director Unit Agreement, dated as of (this “Agreement”), Summit Midstream GP, LLC (the “Company”), as the general partner of Summit Midstream Partners, LP (the “Partnership”), hereby grants to [] (the “Participant”) the following Unit Award pursuant and subject to the terms and condit

Form of Summit Midstream Partners, LP 2012 Long-Term Incentive Plan 2021 Grant Award Agreement (Incorporated herein by reference to Exhibit 10.64 to SMLP’s Annual Report on Form 10-K filed March 1, 2023 (Commission File No. 001-35666))

EX-10.64 12 a2021ltipagreement.htm EX-10.64 EXHIBIT 10.64 SUMMIT MIDSTREAM PARTNERS, LP 2012 LONG-TERM INCENTIVE PLAN 2020 LTIP GRANT AWARD AGREEMENT Pursuant to this 2020 LTIP Grant Award Agreement, dated as of 2021 (this “Agreement”) and the Summit Midstream Partners, LP 2012 Long-Term Incentive Plan, as amended and restated on March 19, 2020 (the “Plan”), Summit Midstream GP, LLC (the “Company”

Summit Midstream Partners, LP 2022 Long-Term Incentive Plan 2023 LTIP Grant Award Agreement for Time-based Phantom Units, effective as of February 23, 2023 (Incorporated herein by reference to Exhibit 10.63 to Summit Midstream Partners, LP’s Annual Report on Form 10-K filed March 1, 2023 (Commission File No. 001-35666)).

EXHIBIT 10.63 SUMMIT MIDSTREAM PARTNERS, LP 2022 LONG-TERM INCENTIVE PLAN 2023 LTIP GRANT AWARD AGREEMENT (Time-based Phantom Units) Pursuant to this 2023 LTIP Grant Award Agreement, dated as of March [ ], 2023 (inclusive of the Grant Notice, Terms and Conditions of the 2023 LTIP Grant and Exhibit A attached hereto, this “Agreement”) and the Summit Midstream Partners, LP 2022 Long-Term Incentive P

First Amendment to Fourth Amended and Restated Agreement of Limited Partnership of Summit Midstream Partners, LP, dated February 23, 2023 (Incorporated herein by reference to Exhibit 3.2 to SMLP's Annual Report on Form 10-K filed March 1, 2023 (Commission File No. 001-35666))

EX-3.2 4 smlp-firstamendtofourthame.htm EX-3.2 EXHIBIT 3.2 FIRST AMENDMENT TO FOURTH AMENDED AND RESTATED AGREEMENT OF LIMITED PARTNERSHIP OF SUMMIT MIDSTREAM PARTNERS, LP This First Amendment (this “Amendment”) to the Fourth Amended and Restated Agreement of Limited Partnership of Summit Midstream Partners, LP, a Delaware limited partnership (the “Partnership”), dated as of May 28, 2020 (the “Par

Summit Midstream Partners, LP Subsidiary Issuers and Guarantors of Registered Securities (Incorporated herein by reference to Exhibit 22.1 to SMLP's Annual Report on Form 10-K filed March 1, 2023 (Commission File No. 001-35666))

exhibit-221subsidiaryiss EXHIBIT 22.1 The below chart lists the subsidiary co‐issuers and guarantors of the 5.75% senior notes due 2025 (the "Senior Notes"). Subsidiary Registered Security Guarantor Status Summit Midstream Holdings, LLC Senior Notes Co-Issuer, Not a guarantor Summit Midstream Finance Corp. Senior Notes Co-Issuer, Not a guarantor Summit Midstream Partners, LP Senior Notes Joint and

Amended and Restated Employment Agreement, effective as of February 23, 2023, by and between Summit Operating Services Company, LLC and Matthew Sicinski (Incorporated herein by reference to Exhibit 10.61 to Summit Midstream Partners, LP’s Annual Report on Form 10-K filed March 1, 2023 (Commission File No. 001-35666)).

EXHIBIT 10.61 Amended and Restated Employment Agreement This Amended and Restated Employment Agreement (the “Agreement”), effective February 23, 2023 (the “Effective Date”), is made by and between Matthew Sicinski (the “Executive”) and Summit Operating Services Company, LLC (together with any of its subsidiaries and affiliates as may employ the Executive from time to time, and any successor(s) the

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 24, 2023 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Empl

Summit Midstream Partners, LP Reports Fourth Quarter and Full Year 2022 Financial and Operating Results & Provides Full Year 2023 Guidance

EXHIBIT 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Reports Fourth Quarter and Full Year 2022 Financial and Operating Results & Provides Full Year 2023 Guidance Houston, Texas (February 24, 2023) – Summit Midstream Partners, LP (NYSE: SMLP) (“Summit”, “SMLP” or the “Partnership”) announced today its financial and operating res

SUMMIT MIDSTREAM PARTNERS, LP AND SUBSIDIARIES PRO FORMA CONDENSED COMBINED FINANCIAL STATEMENTS (UNAUDITED)

EX-99.7 8 smlp-20230214xexx997.htm EX-99.7 EXHIBIT 99.7 SUMMIT MIDSTREAM PARTNERS, LP AND SUBSIDIARIES PRO FORMA CONDENSED COMBINED FINANCIAL STATEMENTS (UNAUDITED) December 2022 acquisitions of Outrigger DJ Midstream and Sterling DJ. As previously disclosed, on December 1, 2022, Summit Midstream Holdings, LLC (“SMP Holdings”), a wholly owned subsidiary of Summit Midstream Partners, LP (including

Unaudited Condensed Combined Financial Statements Sterling Conveyed Entities As of September 30, 2022 and December 31, 2021, and for the Nine Months Ended September 30, 2022 and 2021 2022 2021 ASSETS Current assets Cash 1,939$ 3,275$ Accounts receiva

EX-99.6 7 a2022sterlingconveyedent.htm EX-99.6 Unaudited Condensed Combined Financial Statements Sterling Conveyed Entities As of September 30, 2022 and December 31, 2021, and for the Nine Months Ended September 30, 2022 and 2021 2022 2021 ASSETS Current assets Cash 1,939$ 3,275$ Accounts receivable, net of allowance for doubtful accounts 14,598 8,607 Inventories 1,939 2,657 Other current assets 1

CONSENT OF INDEPENDENT CERTIFIED PUBLIC ACCOUNTANTS

EX-99.2 3 grantthorntonconsent.htm EX-99.2 Exhibit 99.2 CONSENT OF INDEPENDENT CERTIFIED PUBLIC ACCOUNTANTS We have issued our report dated February 14, 2023, with respect to the combined financial statements of Sterling Conveyed Entities included in this Current Report of Summit Midstream Energy, LP on Form 8-K. We consent to the incorporation by reference of said report in the Registration State

Consent of Independent Auditors

Exhibit 99.1 Consent of Independent Auditors We consent to the incorporation by reference in the Registration Statements (Form S-1 No. 333-249831, Form S-3 No. 333-234781 and Form S-8 Nos. 333-184214, 333-189684, 333-237323 and 333-265857) of Summit Midstream Partners, LP and in the related Prospectus of our report dated April 28, 2022, with respect to the consolidated financial statements of Outr

Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K/A (Amendment No. 1) CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): December 1, 2022 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (C

1 Outrigger DJ Midstream LLC and Subsidiary Consolidated Financial Statements (Unaudited) As of September 30, 2022 and December 31, 2021 and for the nine month periods ended September 30, 2022 and September 30, 2021 2 Consolidated Balance Sheets as o

1 Outrigger DJ Midstream LLC and Subsidiary Consolidated Financial Statements (Unaudited) As of September 30, 2022 and December 31, 2021 and for the nine month periods ended September 30, 2022 and September 30, 2021 2 Consolidated Balance Sheets as of September 30, 2022 and December 31, 2021 3 Consolidated Statements of Operations for the periods ended September 30, 2022 and 2021 4 Consolidated St

Combined Financial Statements and Report of Independent Certified Public Accountants Sterling Conveyed Entities December 31, 2021 and 2020 Contents Page Report of Independent Certified Public Accountants 3 Combined Financial Statements Combined state

Combined Financial Statements and Report of Independent Certified Public Accountants Sterling Conveyed Entities December 31, 2021 and 2020 Contents Page Report of Independent Certified Public Accountants 3 Combined Financial Statements Combined statements of financial position 5 Combined statements of operations 6 Combined statements of member’s equity 7 Combined statements of cash flows 8 Notes to combined financial statements 9 GT.

1 Outrigger DJ Midstream LLC and Subsidiary Consolidated Financial Statements as of and for the Years Ended December 31, 2021, and 2020 Outrigger DJ Midstream LLC and Subsidiary Contents 2 Report of Independent Auditors 3 Consolidated Balance Sheets

1 Outrigger DJ Midstream LLC and Subsidiary Consolidated Financial Statements as of and for the Years Ended December 31, 2021, and 2020 Outrigger DJ Midstream LLC and Subsidiary Contents 2 Report of Independent Auditors 3 Consolidated Balance Sheets as of December 31, 2021 and 2020 5 Consolidated Statements of Operations for the years ended December 31, 2021 and 2020 6 Consolidated Statements of Members’ Equity for the years ended December 31, 2021 and 2020 7 Consolidated Statements of Cash Flows for the years ended December 31, 2021 and 2020 8 Notes to Consolidated Financial Statements 9 A member firm of Ernst & Young Global Limited Ernst & Young Suite 4800 370 17th Street Denver, CO 80202 Tel: +1 720 931 4000 Fax: +1 720 931 4444 ey.

SMLP / Summit Midstream Partners LP / SHENKMAN CAPITAL MANAGEMENT INC - SUMMIT MIDSTREAM PARTNERS, LP Passive Investment

SC 13G 1 p23-0803sc13ga.htm SUMMIT MIDSTREAM PARTNERS, LP SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Summit Midstream Partners, LP (Name of Issuer) Common Units (Title of Class of Securities) 866142409 (CUSIP Number) December 31, 2022 (Date of Event Which Requires Filing of this Statement) Check the appropriate

As filed with the Securities and Exchange Commission on January 26, 2023

As filed with the Securities and Exchange Commission on January 26, 2023 Registration No.

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): December 9, 2022 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Emplo

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): November 29, 2022 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Empl

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): December 1, 2022 Summit Midstream

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): December 1, 2022 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Emplo

Summit Midstream Partners, LP Completes Bolt-on Acquisitions in the DJ Basin

EXHIBIT 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Completes Bolt-on Acquisitions in the DJ Basin Houston, Texas (December 1, 2022) – Summit Midstream Partners, LP (NYSE: SMLP) (“Summit”, “SMLP” or the “Partnership”) announced today that its wholly owned subsidiary, Summit Midstream Holdings, LLC (“SMP Holdings”), successfull

Second Lien Pari Passu Intercreditor Agreement, dated as of November 14, 2022, by and among Regions Bank, as the initial second lien representative and the initial second lien collateral agent for the 2021 indenture claimholders, Regions Bank, as additional initial second lien representative and additional initial second lien collateral agent, Summit Midstream Partners, LP, Summit Midstream Holdings, LLC, Summit Midstream Finance Corp., and the other Grantors party thereto (Incorporated herein by reference to Exhibit 10.2 to Summit Midstream Partners, LP’s Current Report on Form 8-K filed November 15, 2022 (Commission File No. 001-35666)).

EXHIBIT 10.2 Execution Version SECOND LIEN PARI PASSU INTERCREDITOR AGREEMENT Dated as of November 14, 2022 among REGIONS BANK, as the Initial Second Lien Representative and the Initial Second Lien Collateral Agent for the 2021 Indenture Claimholders, REGIONS BANK, as Additional Initial Second Lien Representative and Additional Initial Second Lien Collateral Agent, and each other Additional Second

Indenture, dated as of November 14, 2022, by and among Summit Midstream Holdings, LLC, Summit Midstream Finance Corp., the Guarantors party thereto and Regions Bank, as trustee (including form of the 8.500% Senior Secured Second Lien Notes due 2026).

EXHIBIT 4.1 Execution Version SUMMIT MIDSTREAM HOLDINGS, LLC SUMMIT MIDSTREAM FINANCE CORP. As Issuers, SUMMIT MIDSTREAM PARTNERS, LP, As Parent Guarantor AND THE SUBSIDIARY GUARANTORS NAMED ON THE SIGNATURE PAGES HEREOF 8.500% SENIOR SECURED SECOND LIEN NOTES DUE 2026 TEMPORARY NOTES INDENTURE Dated as of November 14, 2022 REGIONS BANK As Trustee and Collateral Agent TABLE OF CONTENTS Page ARTICL

Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): November 14, 2022 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Empl

Collateral Agreement, dated as of November 14, 2022, by and among Summit Midstream Partners, LP, as a pledgor, Summit Midstream Holdings, LLC and Summit Midstream Finance Corp., as pledgors and grantors, the Subsidiary Guarantors party therein, and Regions Bank, as collateral agent (Incorporated herein by reference to Exhibit 10.1 to SMLP’s Current Report on Form 8-K filed November 15, 2022 (Commission File No. 001-35666))

EXHIBIT 10.1 Execution Version COLLATERAL AGREEMENT (Second Lien) Dated as of November 14, 2022, among SUMMIT MIDSTREAM PARTNERS, LP, as a Pledgor, SUMMIT MIDSTREAM HOLDINGS, LLC, as a Pledgor and a Grantor, SUMMIT MIDSTREAM FINANCE CORP., as a Pledgor and a Grantor, each SUBSIDIARY GUARANTOR identified herein each in the capacity or capacities set forth herein, and REGIONS BANK, as Collateral Age

Purchase and Sale Agreement between Summit Midstream Holdings, LLC and Steel Reef US Corp. dated September 19, 2022 (Incorporated herein by reference to Exhibit 10.1 to SMLP’s Quarterly Report on Form 10-Q for the three months ended September 30, 2022 dated November 7, 2022 (Commission File No. 001-35666))

EXHIBIT 10.1 EXECUTION VERSION PURCHASE AND SALE AGREEMENT between SUMMIT MIDSTREAM HOLDINGS, LLC as Seller, and STEEL REEF US CORP. as Buyer dated as of September 19, 2022 America 128276372v.17 Confidential Table of Contents ARTICLE I DEFINITIONS AND CONSTRUCTION 1 1.1Definitions 1 1.2Rules of Construction 11 ARTICLE II PURCHASE AND SALE AND CLOSING 13 2.1Purchase and Sale 13 2.2Purchase Price 13

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2022 or o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file numbe

Summit Midstream Partners, LP Reports Third Quarter 2022 Financial and Operating Results

EXHIBIT 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Reports Third Quarter 2022 Financial and Operating Results Houston, Texas (November 3, 2022) ? Summit Midstream Partners, LP (NYSE: SMLP) (?Summit?, ?SMLP? or the ?Partnership?) announced today its financial and operating results for the three months ended September 30, 2022,

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 3, 2022 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Emplo

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): October 28, 2022 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Emplo

Summit Midstream Partners, LP Announces Synergistic and Accretive Bolt-on Acquisitions in the DJ Basin

EXHIBIT 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Announces Synergistic and Accretive Bolt-on Acquisitions in the DJ Basin ?Summit to acquire Outrigger DJ Midstream LLC, and the operating subsidiaries of Sterling Energy Investments LLC, owners of natural gas gathering and processing systems, a crude oil gathering system, fre

Regulation FD Disclosure, Entry into a Material Definitive Agreement, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): October 14, 2022 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Emplo

Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K/A (Amendment No. 1) CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): September 19, 2022 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction

SUMMIT MIDSTREAM PARTNERS, LP AND SUBSIDIARIES PRO FORMA CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Unaudited)

EXHIBIT 99.1 SUMMIT MIDSTREAM PARTNERS, LP AND SUBSIDIARIES PRO FORMA CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Unaudited) September 2022 disposition of Bison Gathering System. On September 19, 2022, Summit Midstream Holdings, LLC (?SMP Holdings?), a wholly owned subsidiary of Summit Midstream Partners, LP (including its subsidiaries, collectively ?SMLP? or the ?Partnership?), completed the sal

Regulation FD Disclosure, Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Completion of Acquisition or Disposition of Assets

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): September 19, 2022 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Emp

Summit Midstream Partners, LP Announces Sale of its Bison Gas Gathering System in North Dakota

EXHIBIT 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Announces Sale of its Bison Gas Gathering System in North Dakota Houston, Texas (September 19, 2022) ? Summit Midstream Partners, LP (NYSE: SMLP) (?Summit?, ?SMLP? or the ?Partnership?) announced today that its wholly owned subsidiary, Summit Midstream Holdings, LLC (?SMP Hol

Summit Midstream Partners, LP Reports Second Quarter 2022 Financial and Operating Results

EXHIBIT 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Reports Second Quarter 2022 Financial and Operating Results ?Second quarter 2022 net loss of $91.8 million, adjusted EBITDA of $50.5 million and cash flow available for distributions ("Distributable Cash Flow" or ?DCF?) of $25.6 million ?Adjusted EBITDA was impacted by approx

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2022 or o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 00

Purchase and Sale Agreement, dated as of June 9, 2022, among Summit Midstream Holdings, LLC as Seller, Longwood Gathering and Disposal Systems, LP as Buyer, and Summit Midstream Partners LP (Incorporated herein by reference to Exhibit 10.1 to SMLP’s Quarterly Report on Form 10-Q for the three months ended June 30, 2022 dated August 5, 2022 (Commission File No. 001-35666))

Execution Version PURCHASE AND SALE AGREEMENT among SUMMIT MIDSTREAM HOLDINGS, LLC as Seller, LONGWOOD GATHERING AND DISPOSAL SYSTEMS, LP as Buyer, and SOLELY FOR THE LIMITED PURPOSES AS SET FORTH IN SECTION 10.

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 4, 2022 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Employe

SUMMIT MIDSTREAM PARTNERS, LP AND SUBSIDIARIES PRO FORMA CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Unaudited)

EXHIBIT 99.2 SUMMIT MIDSTREAM PARTNERS, LP AND SUBSIDIARIES PRO FORMA CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Unaudited) The following unaudited pro forma condensed consolidated financial statements of Summit Midstream Partners, LP (including its subsidiaries, collectively ?SMLP? or the ?Partnership?) are presented to illustrate the effect to the Partnership?s historical financial position an

Summit Midstream Partners, LP Announces Closing of Lane Gathering and Processing System Sale to a Subsidiary of Matador Resources Company

EXHIBIT 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Announces Closing of Lane Gathering and Processing System Sale to a Subsidiary of Matador Resources Company Houston, Texas (June 30, 2022) ? Summit Midstream Partners, LP (NYSE: SMLP) (?Summit?, ?SMLP? or the ?Partnership?) announced today that its wholly owned subsidiary, Su

Regulation FD Disclosure, Financial Statements and Exhibits, Completion of Acquisition or Disposition of Assets

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): June 30, 2022 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Employer

Filing Fee Table.

Exhibit 107 Calculation of Filing Fee Tables Form S-8 (Form Type) Summit Midstream Partners, LP (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities Security Type Security Class Title Fee Calculation Rule (1) Amount Registered (2) Proposed Maximum Offering Price Per Unit (1) Maximum Aggregate Offering Price (1) Fee Rate (3) Amount of Registration Fee Equity Common units representing limited partner interests Other 1,176,281 units $14.

As filed with the Securities and Exchange Commission on June 27, 2022

As filed with the Securities and Exchange Commission on June 27, 2022 Registration No.

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits, Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): June 24, 2022 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction of incorporation) (Commis

Regulation FD Disclosure, Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): June 9, 2022 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Employer

Summit Midstream Partners, LP Announces Sale of its Lane Gathering and Processing System in the Delaware Basin to a Subsidiary of Matador Resources Company & Reiterates its 2022 Adjusted EBITDA Guidance

Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Announces Sale of its Lane Gathering and Processing System in the Delaware Basin to a Subsidiary of Matador Resources Company & Reiterates its 2022 Adjusted EBITDA Guidance ?Cash sale price of $75 million reduces SMLP?s total leverage by ~0.

Regulation FD Disclosure, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): May 26, 2022 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction of incorporation) (Commiss

Summit Midstream Partners, LP Announces Adjournment of Annual Meeting and Information for Reconvened Annual Meeting

Exhibit 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Announces Adjournment of Annual Meeting and Information for Reconvened Annual Meeting Houston, Texas (May 26, 2022) ? Summit Midstream Partners, LP (NYSE: SMLP) (the ?Partnership? or ?SMLP?) announced today that its 2022 annual meeting of limited partners initially convened a

Regulation FD Disclosure, Financial Statements and Exhibits, Other Events, Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): May 10, 2022 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction of incorporation) (Commiss

Summit Midstream Partners, LP Announces Partial Adjournment of Annual Meeting and Information for Reconvened Annual Meeting

Exhibit 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Announces Partial Adjournment of Annual Meeting and Information for Reconvened Annual Meeting Houston, Texas (May 11, 2022) ? Summit Midstream Partners, LP (NYSE: SMLP) (the ?Partnership? or ?SMLP?) announced today that its 2022 annual meeting of limited partners (the ?Annual

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ? Filed by a Party other than the Registrant ? Check the appropriate box: ? Preliminary Proxy Statement ? Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ? Definitive Proxy State

Amended and Restated Employment Agreement, effective as of September 4, 2020, by and between Summit Operating Services Company, LLC and Heath Deneke (Incorporated herein by reference to Exhibit 10.2 to SMLP’s Quarterly Report on Form 10-Q for the three months ended March 31, 2022 dated May 5, 2022 (Commission File No. 001-35666))

Exhibit 10.2 Amended and Restated Employment Agreement This Amended and Restated Employment Agreement (the ?Agreement?), effective September 4, 2020 (the ?Effective Date?), is made by and between Heath Deneke (the ?Executive?) and Summit Operating Services Company, LLC (together with any of its subsidiaries and affiliates as may employ the Executive from time to time, and any successor(s) thereto,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2022 or o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 0

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 3, 2022 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Employer o

Summit Midstream Partners, LP Reports First Quarter 2022 Financial and Operating Results

EXHIBIT 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Reports First Quarter 2022 Financial and Operating Results ?First quarter 2022 net loss of $5 thousand, adjusted EBITDA of $56.8 million and cash flow available for distributions ("Distributable Cash Flow" or ?DCF?) of $31.8 million ?Generated significant free cash flow in Q1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

DEFA14A 1 d282658ddefa14a.htm DEFA14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ? Filed by a Party other than the Registrant ? Check the appropriate box: ? Preliminary Proxy Statement ? Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ? Definitive Proxy State

SMLP / Summit Midstream Partners LP / Invesco Ltd. - SEC SCHEDULE 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 4 )* Summit Midstream Partners LP (Name of Issuer) Partnership Interest (Title of Class of Securities) 866142409 (CUSIP Number) March 31, 2022 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to

Summit Midstream Partners, LP 2022 Long-Term Incentive Plan (incorporated herein by reference to Appendix B to SMLP’s definitive proxy statement on Schedule 14A filed March 31, 2022 (Commission File No. 001-35666))

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ? Filed by a Party other than the Registrant ? Check the appropriate box: ?Preliminary Proxy Statement ?Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ?Definitive Proxy Statemen

Regulation FD Disclosure, Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): February 28, 2022 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Empl

Summit Midstream Partners, LP Announces the Appointment of Rommel M. Oates to the Board of Directors of its General Partner

EXHIBIT 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Announces the Appointment of Rommel M. Oates to the Board of Directors of its General Partner Houston, Texas (February 28, 2022) ? Summit Midstream Partners, LP (NYSE: SMLP) (the ?Partnership?) announced today that Rommel M. Oates has been appointed to the Board of Directors

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-K x ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2021 or o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-35666 Summit Midstream Partners

Form of Summit Midstream Partners, LP 2012 Long-Term Incentive Plan Grant Award Agreement (Incorporated herein by reference to Exhibit 10.54 to SMLP’s Annual Report on Form 10-K filed February 28, 2022 (Commission File No. 001-35666))

EXHIBIT 10.54 February 24, 2022 SUMMIT MIDSTREAM PARTNERS, LP 2012 LONG-TERM INCENTIVE PLAN LTIP GRANT AWARD AGREEMENT Pursuant to this LTIP Grant Award Agreement, dated as of (this ?Agreement?) and the Summit Midstream Partners, LP 2012 Long-Term Incentive Plan, as amended and restated (the ?Plan?), Summit Midstream GP, LLC (the ?Company?), as the general partner of Summit Midstream Partners, LP

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 25, 2022 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Empl

Summit Midstream Partners, LP Reports Fourth Quarter and Full Year 2021 Financial and Operating Results & Provides Full Year 2022 Guidance

EXHIBIT 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Reports Fourth Quarter and Full Year 2021 Financial and Operating Results & Provides Full Year 2022 Guidance ?Fourth quarter 2021 net loss of $16.2 million, adjusted EBITDA of $54.7 million and cash flow available for distributions ("Distributable Cash Flow" or ?DCF?) of $29.

JOINT FILING AGREEMENT

EX-99.1 2 tm226500d5ex99-1.htm EXHIBIT 99.1 Exhibit 99.1 JOINT FILING AGREEMENT The undersigned hereby agree that they are filing this statement jointly pursuant to Rule 13d-1(k)(1). Each of them is responsible for the timely filing of such Schedule 13G and any amendments thereto, and for the completeness and accuracy of the information concerning such person contained therein; but none of them is

SMLP / Summit Midstream Partners LP / ARES MANAGEMENT LLC - SC 13G/A Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1) Summit Midstream Partners, LP (Name of Issuer) Common Units (Title of Class of Securities) 866142409 (CUSIP Number) December 31, 2021 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which

Regulation FD Disclosure, Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): February 8, 2022 (February 7, 2022) Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction of

Summit Midstream Partners, LP Announces Senior Leadership Changes

Exhibit 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Announces Senior Leadership Changes Houston, Texas (February 8, 2022) ? Summit Midstream Partners, LP (NYSE: SMLP) (the ?Partnership?) announced today that Marc Stratton, the Executive Vice President and Chief Financial Officer of Summit Midstream GP, LLC (the ?Company?) will

Regulation FD Disclosure, Unregistered Sales of Equity Securities, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): January 14, 2022 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction of incorporation) (Com

Summit Midstream Partners, LP Announces Final Results of Series A Preferred Unit Exchange Offer

Exhibit 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Announces Final Results of Series A Preferred Unit Exchange Offer Houston, Texas (January 14, 2022) ? Summit Midstream Partners, LP (NYSE: SMLP) (the ?Partnership?) announced today the final results of its offer to exchange (the ?Exchange Offer?) any and all of its 9.50% Seri

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 AMENDMENT NO. 3 SCHEDULE TO Tender Offer Statement under Section 14(d)(1) or 13(e)(1) of the Securities Exchange Act of 1934 Summit Midstream Partners, LP (Name of Subject Compan

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 AMENDMENT NO. 3 to SCHEDULE TO Tender Offer Statement under Section 14(d)(1) or 13(e)(1) of the Securities Exchange Act of 1934 Summit Midstream Partners, LP (Name of Subject Company and Filing Person (Issuer)) 9.50% Series A Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units (Title of Class of Securities)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 AMENDMENT NO. 2 SCHEDULE TO Tender Offer Statement under Section 14(d)(1) or 13(e)(1) of the Securities Exchange Act of 1934 Summit Midstream Partners, LP (Name of Subject Compan

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 AMENDMENT NO. 2 to SCHEDULE TO Tender Offer Statement under Section 14(d)(1) or 13(e)(1) of the Securities Exchange Act of 1934 Summit Midstream Partners, LP (Name of Subject Company and Filing Person (Issuer)) 9.50% Series A Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units (Title of Class of Securities)

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): January 13, 2022 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction of incorporation) (Com

Summit Midstream Partners, LP Announces Preliminary Results of Series A Preferred Unit Exchange Offer

Exhibit 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Announces Preliminary Results of Series A Preferred Unit Exchange Offer Houston, Texas (January 13, 2022) ? Summit Midstream Partners, LP (NYSE: SMLP) (the ?Partnership?) announced today the preliminary results of its offer to exchange (the ?Exchange Offer?) any and all of it

Regulation FD Disclosure, Financial Statements and Exhibits, Other Events, Shareholder Director Nominations

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): January 7, 2022 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction of incorporation) (Comm

Summit Midstream Partners, LP Provides Update on Series A Preferred Unit Exchange Offer

Exhibit 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Provides Update on Series A Preferred Unit Exchange Offer Houston, Texas (January 7, 2022) ? Summit Midstream Partners, LP (NYSE: SMLP) (the ?Partnership?) announced today updates regarding its offer to exchange (the ?Exchange Offer?) any and all of its 9.50% Series A Fixed-t

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 AMENDMENT NO. 1 SCHEDULE TO Tender Offer Statement under Section 14(d)(1) or 13(e)(1) of the Securities Exchange Act of 1934 Summit Midstream Partners, LP (Name of Subject Compan

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 AMENDMENT NO. 1 to SCHEDULE TO Tender Offer Statement under Section 14(d)(1) or 13(e)(1) of the Securities Exchange Act of 1934 Summit Midstream Partners, LP (Name of Subject Company and Filing Person (Issuer)) 9.50% Series A Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units (Title of Class of Securities)

Summit Midstream Partners, LP Announces Series A Preferred Unit Exchange Offer

Exhibit 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Announces Series A Preferred Unit Exchange Offer Houston, Texas (December 14, 2021) ? Summit Midstream Partners, LP (NYSE: SMLP) (the ?Partnership?) announced today that it has commenced an offer to exchange (the ?Exchange Offer?) any and all of its 9.50% Series A Fixed-to-Fl

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): December 14, 2021 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction of incorporation) (Co

Offer to Exchange, dated December 14, 2021.

Exhibit (a)(1)(i) Offer to Exchange 9.50% Series A Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units (Liquidation Preference $1,000) for Common Units We are offering to exchange (the ?Exchange Offer?), upon the terms and subject to the conditions set forth in this offer to exchange (as it may be supplemented and amended from time to time, this ?Offer to Exchange?) and the acco

Tender and Support Agreement, dated December 14, 2021.

Exhibit (d)(4) TENDER AND SUPPORT AGREEMENT This TENDER AND SUPPORT AGREEMENT (this ?Agreement?), dated as of December 14, 2021, is made and entered into by and among Summit Midstream Partners, LP, a Delaware limited partnership (the ?Partnership?), Goldman Sachs Asset Management, L.

Form of Letter of Transmittal.

Exhibit (a)(1)(ii) LETTER OF TRANSMITTAL OFFER TO EXCHANGE 9.50% Series A Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units (Liquidation Preference $1,000) (CUSIP No. 866142 AA0) of Summit Midstream Partners, LP for Common Units of Summit Midstream Partners, LP THE EXCHANGE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT 11:59 P.M., NEW YORK CITY TIME, ON JANUARY 12, 2022 UNLESS EX

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE TO Tender Offer Statement under Section 14(d)(1) or 13(e)(1) of the Securities Exchange Act of 1934 Summit Midstream Partners, LP (Name of Subject Company and Filing Per

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE TO Tender Offer Statement under Section 14(d)(1) or 13(e)(1) of the Securities Exchange Act of 1934 Summit Midstream Partners, LP (Name of Subject Company and Filing Person (Issuer)) 9.50% Series A Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units (Title of Class of Securities) 866142AA0 (CUSIP Nu

Loan and Security Agreement, dated as November 2, 2021, among Summit Midstream Holdings, as borrower, Summit Midstream Partners, LP and certain subsidiaries from time to time party thereto, as guarantors, Bank of America, N.A., as agent, ING Capital LLC, Royal Bank of Canada and Regions Bank, as co-syndication agents, joint lead arrangers and joint bookrunners (Incorporated herein by reference to Exhibit 10.5 to SMLP’s Quarterly Report on Form 10-Q for the three months ended September 30, 2021 dated November 4, 2021 (Commission File No. 333-183466))

EXHIBIT 10.5 Execution Version LOAN AND SECURITY AGREEMENT Dated as of November 2, 2021 SUMMIT MIDSTREAM HOLDINGS, LLC, as Borrower and SUMMIT MIDSTREAM PARTNERS, LP and CERTAIN SUBSIDIARIES FROM TIME TO TIME PARTY HERETO, as Guarantors BANK OF AMERICA, N.A., as Agent ING CAPITAL LLC, ROYAL BANK OF CANADA and REGIONS BANK, as Co-Syndication Agents BANK OF AMERICA, N.A., ING CAPITAL LLC, RBC CAPITA

Intercreditor Agreement, dated as of November 2, 2021, by and among Bank of America, N.A., as first lien representative and collateral agent for the initial first lien claimholders, Regions Bank, as second lien representative for the initial second lien claimholders and as collateral agent for the initial second lien claimholders, acknowledged and agreed to by Summit Midstream Holdings, LLC and the other grantors referred to therein (Incorporated herein by reference to Exhibit 10.6 to SMLP’s Quarterly Report on Form 10-Q for the three months ended September 30, 2021 dated November 4, 2021 (Commission File No. 333-183466))

Certain identified information (indicated by ?[***]?) has been excluded from this exhibit because it is both not material and the registrant customarily and actually treats that information as private or confidential.

Collateral Agreement, dated as of November 2, 2021, by and among Summit Midstream Partners, LP, as a pledgor, Summit Midstream Holdings, LLC and Summit Midstream Finance Corp., as pledgors and grantors, the Subsidiary Guarantors party therein, and Regions Bank, as collateral agent (Incorporated herein by reference to Exhibit 10.4 to SMLP’s Quarterly Report on Form 10-Q for the three months ended September 30, 2021 dated November 4, 2021 (Commission File No. 333-183466))

EXHIBIT 10.4 Execution Version COLLATERAL AGREEMENT (Second Lien) Dated as of November 2, 2021, among SUMMIT MIDSTREAM PARTNERS, LP, as a Pledgor, SUMMIT MIDSTREAM HOLDINGS, LLC, as a Pledgor and a Grantor, SUMMIT MIDSTREAM FINANCE CORP., as a Pledgor and a Grantor, each SUBSIDIARY GUARANTOR identified herein each in the capacity or capacities set forth herein, and REGIONS BANK, as Collateral Agen

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2021 or ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file numbe

Indenture, dated as of November 2, 2021, by and among Summit Midstream Holdings, LLC, Summit Midstream Finance Corp., the Guarantors party thereto and Regions Bank, as trustee (including form of the 8.500% Senior Secured Second Lien Notes due 2026) (Incorporated herein by reference to Exhibit 4.1 to SMLP's Quarterly Report on Form 10-Q dated November 4, 2021 (Commission File No. 001-35666))

Certain identified information (indicated by ?[***]?) has been excluded from this exhibit because it is both not material and the registrant customarily and actually treats that information as private or confidential.

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 4, 2021 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Emplo

Summit Midstream Partners, LP Reports Third Quarter 2021 Financial and Operating Results

Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Reports Third Quarter 2021 Financial and Operating Results ?Third quarter 2021 net income of $7.

SMLP / Summit Midstream Partners LP / ENERGY CAPITAL PARTNERS II, LLC - SC 13D/A Activist Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 10)* Summit Midstream Partners, LP (Name of Issuer) Common Units (Title of Class of Securities) 866142102 (CUSIP Number) Chris Leininger 12680 High Bluff Drive Suite 400 San Diego, California 92130 858-703-4400 (Name, Address and Telephone Number of Person A

Summit Midstream Partners, LP Announces Pricing of Private Offering of $700 Million Senior Secured Second Lien Notes

Exhibit 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Announces Pricing of Private Offering of $700 Million Senior Secured Second Lien Notes Houston, Texas (October 19, 2021) ? Summit Midstream Partners, LP (NYSE: SMLP) (the ?Partnership?) announced today that Summit Midstream Holdings, LLC, a Delaware limited liability company

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): October 19, 2021 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction of incorporation) (Com

Summit Midstream Partners, LP Announces Private Offering of $700 Million Senior Secured Second Lien Notes and Conditional Redemption of 5.50% Senior Notes due 2022

Exhibit 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Announces Private Offering of $700 Million Senior Secured Second Lien Notes and Conditional Redemption of 5.50% Senior Notes due 2022 Houston, Texas (October 13, 2021) ? Summit Midstream Partners, LP (NYSE: SMLP) (the ?Partnership?) announced today that, subject to market and

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): October 13, 2021 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction of incorporation) (Com

Joint Factual Statement (Incorporated herein by reference to Exhibit 10.1 to SMLP’s Quarterly Report on Form 10-Q for the three months ended June 30, 2021 dated August 9, 2021 (Commission File No. 333-183466))

Case 1:21-cr-00152-DMT Document 2 Filed 08/05/21 Page 1 of 17 UNITED STATES DISTRICT COURT DISTRICT OF NORTH DAKOTA UNITED STATES OF AMERICA, v.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q (Mark One) ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2021 or ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 00

Criminal Plea Agreement (Incorporated herein by reference to Exhibit 10.2 to SMLP’s Quarterly Report on Form 10-Q for the three months ended June 30, 2021 dated August 9, 2021 (Commission File No. 333-183466))

Case 1:21-cr-00152-DMT Document 4 Filed 08/05/21 Page 1 of 14 UNITED STATES DISTRICT COURT DISTRICT OF NORTH DAKOTA UNITED STATES OF AMERICA, v.

Consent Decree (Incorporated herein by reference to Exhibit 10.3 to SMLP’s Quarterly Report on Form 10-Q for the three months ended June 30, 2021 dated August 9, 2021 (Commission File No. 333-183466))

IN THE UNITED STATES DISTRICT COURT DISTRICT OF NORTH DAKOTA WESTERN DIVISION UNITED STATES OF AMERICA, and the STATE OF ) NORTH DAKOTA, NORTH DAKOTA DEPARTMENT ) OF ENVIRONMENTAL QUALITY and NORTH ) DAKOTA GAME AND FISH DEPARTMENT, ) ) Civil Action No.

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 6, 2021 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Employe

Summit Midstream Partners, LP Reports Second Quarter 2021 Financial and Operating Results

Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Reports Second Quarter 2021 Financial and Operating Results ?Second quarter 2021 net loss of $19.

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 21, 2021 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Employer

Summit Midstream Partners, LP Provides Updated 2021 Financial Guidance

EXHIBIT 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Provides Updated 2021 Financial Guidance ?Increasing full year 2021 adjusted EBITDA guidance by $12.5 million, or 5.7% at the midpoint, to a new range of $225 million to $240 million ?Maintaining full year 2021 capital expenditure guidance of $20 million to $35 million ?Revol

Quarterly Report - 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q (Mark One) ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2021 or ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-35666 Summit Mi

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 7, 2021 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction (Commission (IRS Employer o

Credit Agreement, dated as of March 8, 2021, among Summit Permian Transmission, LLC, as borrower, MUFG Bank Ltd., as administrative agent, Mizuho Bank (USA), as collateral agent, ING Capital LLC, Mizuho Bank, Ltd. and MUFG Union Bank, N.A., as L/C issuers, coordinating lead arrangers and joint bookrunners, and the lenders from time to time party thereto (Incorporated herein by reference to Exhibit 10.1 to SMLP’s Quarterly Report on Form 10-Q dated May 7, 2021 (Commission File No. 333-183466))

Certain identified information (indicated by ?[***]?) has been excluded from this exhibit because it is both not material and the registrant customarily and actually treats that information as private or confidential.

Summit Midstream Partners, LP Reports First Quarter 2021 Financial and Operating Results

EXHIBIT 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Reports First Quarter 2021 Financial and Operating Results ? First quarter 2021 net income of $9.0 million, adjusted EBITDA of $60.4 million and Distributable Cash Flow (?DCF?) of $46.2 million ? First quarter 2021 operating expenses reflect a reduction of $4.3 million relati

- POS AM

POS AM 1 d170620dposam.htm POS AM Table of Contents As filed with the Securities and Exchange Commission on April 26, 2021 Registration No. 333-243483 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Post-Effective Amendment No. 1 to FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 SUMMIT MIDSTREAM PARTNERS, LP (Exact name of registrant as specified in its ch

Annual Report - 10-K/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-K/A Amendment No. 1 ? ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2020 or ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-35666 Summit

- POS AM

Table of Contents As filed with the Securities and Exchange Commission on April 26, 2021 Registration No.

Description of Common Units (Incorporated herein by reference to Exhibit 4.1 to SMLP’s Form 10-K/A dated April 26, 2021 (Commission File No. 333-183466))

Exhibit 4.1 Description of Our Common Units The following description of the common units representing limited partner interests (?common units?) in Summit Midstream Partners, LP, a Delaware limited partnership (the ?Partnership? or, as the context requires, ?we,? ?us? or ?our?), is a summary and is subject to, and qualified in its entirety by, reference to the provisions of our Fourth Amended and

- SC TO-I/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 AMENDMENT NO. 5 to SCHEDULE TO Tender Offer Statement under Section 14(d)(1) or 13(e)(1) of the Securities Exchange Act of 1934 Summit Midstream Partners, LP (Name of Subject Company and Filing Person (Issuer)) 9.50% Series A Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units (Title of Class of Securities)

Summit Midstream Partners, LP Announces Final Results of Series A Preferred Unit Exchange Offer

EXHIBIT 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Announces Final Results of Series A Preferred Unit Exchange Offer Houston, Texas (April 15, 2021) ? Summit Midstream Partners, LP (NYSE: SMLP) (the ?Partnership?) announced today the final results of its offer to exchange (the ?Exchange Offer?) its 9.50% Series A Fixed-to-Flo

Summit Midstream Partners, LP 2,306,972 Common Units Representing Limited Partner Interests

424B3 Filed pursuant to Rule 424(b)(3) Registration No. 333-249831 PROSPECTUS SUPPLEMENT NO. 5 (to prospectus dated November 16, 2020) Summit Midstream Partners, LP 2,306,972 Common Units Representing Limited Partner Interests This prospectus supplement is being filed to update and supplement information contained in the prospectus dated November 16, 2020 (the “prospectus”), relating to up to 2,30

Regulation FD Disclosure, Unregistered Sales of Equity Securities, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): April 15, 2021 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction of incorporation) (Commi

Summit Midstream Partners, LP 666,667 Common Units Representing Limited Partner Interests

Filed pursuant to Rule 424(b)(3) Registration No. 333-243483 PROSPECTUS SUPPLEMENT NO. 9 (to prospectus dated August 27, 2020) Summit Midstream Partners, LP 666,667 Common Units Representing Limited Partner Interests This prospectus supplement is being filed to update and supplement information contained in the prospectus dated August 27, 2020 (the ?prospectus?), relating to up to 666,667 common u

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): April 14, 2021 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction of incorporation) (Commi

- SC TO-I/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 AMENDMENT NO. 4 to SCHEDULE TO Tender Offer Statement under Section 14(d)(1) or 13(e)(1) of the Securities Exchange Act of 1934 Summit Midstream Partners, LP (Name of Subject Company and Filing Person (Issuer)) 9.50% Series A Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units (Title of Class of Securities)

Summit Midstream Partners, LP Announces Preliminary Results of Series A Preferred Unit Exchange Offer

EXHIBIT 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Announces Preliminary Results of Series A Preferred Unit Exchange Offer Houston, Texas (April 14, 2021) ? Summit Midstream Partners, LP (NYSE: SMLP) (the ?Partnership?) announced today preliminary results regarding its offer to exchange (the ?Exchange Offer?) its 9.50% Series

- SC TO-I/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 AMENDMENT NO. 3 to SCHEDULE TO Tender Offer Statement under Section 14(d)(1) or 13(e)(1) of the Securities Exchange Act of 1934 Summit Midstream Partners, LP (Name of Subject Company and Filing Person (Issuer)) 9.50% Series A Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units (Title of Class of Securities)

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): April 7, 2021 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction of incorporation) (Commis

Summit Midstream Partners, LP Announces Extension of Expiration Date in Series A Preferred Unit Exchange Offer

Exhibit 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Announces Extension of Expiration Date in Series A Preferred Unit Exchange Offer Houston, Texas (April 7, 2021) ? Summit Midstream Partners, LP (NYSE: SMLP) (the ?Partnership?) announced today that it has amended its offer to exchange (the ?Exchange Offer?) its 9.50% Series A

- SC TO-I/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 AMENDMENT NO. 2 to SCHEDULE TO Tender Offer Statement under Section 14(d)(1) or 13(e)(1) of the Securities Exchange Act of 1934 Summit Midstream Partners, LP (Name of Subject Company and Filing Person (Issuer)) 9.50% Series A Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units (Title of Class of Securities)

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): March 23, 2021 Summit Midstream Partners, LP (Exact name of registrant as specified in its charter) Delaware 001-35666 45-5200503 (State or other jurisdiction of incorporation) (Commi

Summit Midstream Partners, LP Announces Amendment to Series A Preferred Unit Exchange Offer

Exhibit 99.1 Summit Midstream Partners, LP 910 Louisiana Street, Suite 4200 Houston, TX 77002 Summit Midstream Partners, LP Announces Amendment to Series A Preferred Unit Exchange Offer Houston, Texas (March 23, 2021) ? Summit Midstream Partners, LP (NYSE: SMLP) (the ?Partnership?) announced today that it has amended its offer to exchange (the ?Exchange Offer?) its 9.50% Series A Fixed-to-Floating

- SC TO-I/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 AMENDMENT NO. 1 to SCHEDULE TO Tender Offer Statement under Section 14(d)(1) or 13(e)(1) of the Securities Exchange Act of 1934 Summit Midstream Partners, LP (Name of Subject Company and Filing Person (Issuer)) 9.50% Series A Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units (Title of Class of Securities)