X0306 4 2015-12-22 0 0001513965 American Midstream Partners, LP AMID 0001502553 ARCLIGHT ENERGY PARTNERS FUND V, L.P. C/O ARCLIGHT CAPITAL PARTNERS, LLC 200 CLARENDON STREET, 55TH FLOOR BOSTON MA 02117 1 0 1 0 0001526603 American Midstream GP, LLC ATTENTION: WILLIAM B. MATHEWS 1400 16TH STREET, SUITE 310 DENVER CO 80202 1 0 1 0 0001638285 Magnolia Infrastructure Partners, LLC C/O ARCLIGHT CAPITAL PARTNERS, LLC 200 CLARENDON STREET, 55TH FLOOR BOSTON MA 02117 1 0 1 0 0001575227 High Point Infrastructure Partners, LLC C/O ARCLIGHT CAPITAL PARTNERS, LLC 200 CLARENDON STREET, 55TH FLOOR BOSTON MA 02117 1 0 1 0 0001441290 ArcLight Capital Holdings, LLC C/O ARCLIGHT CAPITAL PARTNERS, LLC 200 CLARENDON STREET, 55TH FLOOR BOSTON MA 02117 1 0 1 0 0001502945 ArcLight Capital Partners, LLC 200 CLARENDON STREET, 55TH FLOOR BOSTON MA 02117 1 0 1 0 0001405456 Revers Daniel R C/O ARCLIGHT CAPITAL PARTNERS, LLC 200 CLARENDON STREET, 55TH FLOOR BOSTON MA 02117 1 0 1 0 Common Units (Limited Partner Interests) 2015-12-22 4 P 0 75072 5.79 A 693993 I See Footnote The price reported in Column 4 is a weighted average price. These common units were purchased in multiple transactions ranging from $5.16 to $6.00, inclusive. 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 range set forth above. Does not include (i) 6,477,957 Series A-1 Convertible Preferred Units (the "Series A-1 Units") held directly by High Point Infrastructure Partners, LLC ("HPIP"), which do not have an expiration date and are convertible in whole or in part on an approximate 1.098:1 basis into common units at any time after January 1, 2014, (ii) 2,762,503 Series A-2 Convertible Preferred Units held by Magnolia (as defined below), which do not have an expiration date and are convertible in whole or in part on an approximate 1.098:1 basis into common units at any time or (Continued from Footnote 2) (iii) 1,349,609 Series B Convertible Preferred Units held directly by American Midstream GP, LLC, the general partner of the Issuer (the "General Partner"), which do not have an expiration date and are convertible in whole or in part on a one-for-one basis into common units at any time after January 22, 2016 or, prior to that date, with the consent of the required lenders under the Issuer's credit agreement at the reporting person's election. Busbar II, LLC ("Busbar"), a direct, wholly owned subsidiary of ArcLight Energy Partners Fund V, L.P. ("Fund V"), directly owns 75,072 common units out of the 693,993 common units reflected in Column 5. Magnolia Infrastructure Partners, LLC, an indirect, wholly owned subsidiary of Fund V ("Magnolia"), directly owns 618,921 common units out of the 693,993 common units reflected in Column 5. ArcLight Capital Holdings, LLC ("ArcLight Holdings") is the sole manager and member of ArcLight Capital Partners, LLC ("ArcLight Partners" and, together with ArcLight Holdings and Fund V, the "ArcLight Entities"). ArcLight Partners is the investment adviser to Fund V. ArcLight Holdings is the manager of the general partner of Fund V. Mr. Revers is a manager of ArcLight Holdings and a managing partner of ArcLight Partners and has certain voting and dispositive rights as a member of ArcLight Partners' investment committee. Fund V directly owns Busbar, indirectly owns Magnolia and, through indirectly controlled subsidiaries, Fund V owns approximately 90% of the ownership interest in HPIP, which in turn owns 95% of the General Partner. As a result, the ArcLight Entities and Mr. Revers may be deemed to indirectly beneficially own the securities of the Issuer held by Busbar, Magnolia, HPIP and the General Partner, but disclaim beneficial ownership except to the extent of their respective pecuniary interests therein. s/ Daniel R. Revers, MAGNOLIA INFRASTRUCTURE PARTNERS, LLC, By: Daniel R. Revers, President 2015-12-23 /s/ Daniel R. Revers, HIGH POINT INFRASTRUCTURE PARTNERS, LLC, By: Daniel R. Revers, President 2015-12-23 /s/ William B. Mathews, AMERICAN MIDSTREAM GP, LLC, By: William B. Mathews, Senior Vice President 2015-12-23 /s/ Daniel R. Revers, ARCLIGHT CAPITAL HOLDINGS, LLC, By: Daniel R. Revers, Managing Partner 2015-12-23 /s/ Daniel R. Revers, ARCLIGHT CAPITAL PARTNERS, LLC, By: Daniel R. Revers, Managing Partner 2015-12-23 /s/ Daniel R. Revers, ARCLIGHT ENERGY PARTNERS FUND V, L.P., By: ArcLight PEF GP V, LLC, its General Partner, By: ArcLight Capital Holdings, LLC, its Manager, By: Daniel R. Revers, Managing Partner 2015-12-23 /s/ Daniel R. Revers 2015-12-23