Security	Date	Code	Shares	Price	A/D	Owned after	D/I	Nature of ownership
COMMON UNITS (LIMITED PARTNER INTERESTS)^F1,F2,F3,F4	Feb 24, 2016	P	59,627	$15.80	A	2,675,638	I	BY: SMLP HOLDINGS, LLC
COMMON UNITS (LIMITED PARTNER INTERESTS)^F1,F3,F5,F4	Feb 25, 2016	P	46,492	$13.17	A	2,722,130	I	BY: SMLP HOLDINGS, LLC
COMMON UNITS (LIMITED PARTNER INTERESTS)^F1,F3,F6,F4	Feb 25, 2016	P	21,100	$13.92	A	2,743,230	I	BY: SMLP HOLDINGS, LLC
COMMON UNITS (LIMITED PARTNER INTERESTS)^F1,F3,F7,F4	Feb 25, 2016	P	15,885	$14.97	A	2,759,115	I	BY: SMLP HOLDINGS, LLC
COMMON UNITS (LIMITED PARTNER INTERESTS)^F1,F3,F8,F4	Feb 25, 2016	P	1,400	$15.86	A	2,760,515	I	BY: SMLP HOLDINGS, LLC
COMMON UNITS (LIMITED PARTNER INTERESTS)^F1,F3,F9,F4	Feb 26, 2016	P	84,877	$12.89	A	2,845,392	I	BY: SMLP HOLDINGS, LLC
COMMON UNITS (LIMITED PARTNER INTERESTS)^F10	holding	—	—		—	29,703,421	I	BY: SUMMIT MIDSTREAM PARTNERS HOLDINGS, LLC
COMMON UNITS (LIMITED PARTNER INTERESTS)^F10	holding	—	—		—	151,160	I	BY: SUMMIT MIDSTREAM PARTNERS, LLC

Table II — derivative securities

No Table II lines on this filing.

Explanation of responses

F1Units were purchased pursuant to a 10b5-1 plan entered into on December 15, 2015.
F10ECP 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 Summit Midstream Partners Holdings, LLC (''SMPH'') and may be deemed to have indirect beneficial ownership of the 29,703,421 common units held by SMPH in addition to the 151,160 common units held directly. Accordingly, ECP and the ECP Funds may be deemed to indirectly beneficially own the 29,854,581 common units held by Summit and SMPH but disclaim beneficial ownership except to the extent of their pecuniary interest therein.
F2These common units were purchased in multiple transactions ranging from $15.25 to $16.05, inclusive.
F3The price reported in Column 4 is a weighted average price. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of common units purchased at each separate price within the ranges set forth in footnotes 2, 5, 6, 7, 8 and 9.
F4Energy 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 2,845,392 common units held by SMLP Holdings but disclaim beneficial ownership except to the extent of their pecuniary interest therein.
F5These common units were purchased in multiple transactions ranging from $12.57 to $13.56, inclusive.
F6These common units were purchased in multiple transactions ranging from $13.57 to $14.55, inclusive.
F7These common units were purchased in multiple transactions ranging from $14.58 to $15.57, inclusive.
F8These common units were purchased in multiple transactions ranging from $15.69 to $16.05, inclusive.
F9These common units were purchased in multiple transactions ranging from $12.70 to $13.00, inclusive.