Security	Date	Code	Shares	Price	A/D	Owned after	D/I	Nature of ownership
COMMON UNITS (LIMITED PARTNER INTERESTS)^F1,F2,F3	Feb 3, 2017	S	4,000,000	$24.00	D	25,854,581	I	BY: SUMMIT MIDSTREAM PARTNERS HOLDINGS, LLC
COMMON UNITS (LIMITED PARTNER INTERESTS)^F2,F3	holding	—	—		—	5,915,827	I	BY: SMLP HOLDINGS, LLC

Table II — derivative securities

No Table II lines on this filing.

Explanation of responses

F1On February 3, 2017, Summit Midstream Partners Holdings, LLC ("SMPH") sold 4,000,000 common units representing limited partner interests in the Issuer to the underwriters in a public offering.
F2Energy Capital Partners II, LP ("ECP II") and certain of its parallel funds (collectively, the "SMLP Holdings Owners") collectively hold all of the membership interests in SMLP Holdings, LLC(''SMLP Holdings''). Energy Capital Partners II, LLC (''ECP'') indirectly controls the SMLP Holdings Owners. Accordingly, ECP and the SMLP Holdings Owners may be deemed to indirectly beneficially own the 5,915,827 common units held by SMLP Holdings but disclaim beneficial ownership except to the extent of their pecuniary interest therein.
F3ECP indirectly controls ECP II, Energy Capital Partners II-A, LP (''ECP II-A''), Energy Capital Partners II-B IP, LP (''ECP II-B''), Energy Capital Partners II-C (Summit IP), LP (''ECP II-C'') and Energy Capital Partners II (Summit Co-Invest), LP ("ECP Summit Co-Invest" and together with ECP II, ECP II-A, ECP II-B and ECP II-C, the ''ECP Funds''), which collectively hold more than a majority of the membership interests in Summit Midstream Partners, LLC ("Summit") and are entitled to appoint all the directors of Summit. Summit is the sole member of SMPH and may be deemed to have indirect beneficial ownership of the 25,854,581 common units held by SMPH. Accordingly, ECP and the ECP Funds may be deemed to indirectly beneficially own the 25,854,581 common units held by SMPH but disclaim beneficial ownership except to the extent of their pecuniary interest therein.