A rollforward of the number of common limited partner and General Partner units follows.

	Limited partners
	Series A Preferred Units		Common		General Partner
Units, January 1, 2018		300,000		73,085,996		1,490,999
Net units issued under the SMLP LTIP		—		269,779		—
Units, September 30, 2018		300,000		73,355,775		1,490,999

At-the-market Program. In 2017, we executed a new equity distribution agreement and filed a prospectus and a prospectus supplement with the SEC for the issuance and sale from time to time of SMLP common units having an aggregate offering price of up to $150.0 million (the "ATM Program"). These sales will be made (i) pursuant to the terms of the equity distribution agreement between us and the sales agents named therein and (ii) by means of ordinary brokers' transactions at market prices, in block transactions or as otherwise agreed between us and the sales agents. Sales of our common units may be made in negotiated transactions or transactions that are deemed to be at-the-market offerings as defined by SEC rules.

During the three and nine months ended September 30, 2018, there were no transactions under the ATM Program. Following the effectiveness of the new ATM registration statement and after taking into account the aggregate sales price of common units sold under the ATM Program through September 30, 2018, we have the capacity to issue additional common units under the ATM Program up to an aggregate $132.3 million.

Series A Preferred Units. In 2017, we issued 300,000 Series A Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units (the “Series A Preferred Units”) representing limited partner interests in the Partnership at a price to the public of $1,000 per unit as described in the 2017 Annual Report.

Noncontrolling Interest. We have recorded Summit Investments' indirect retained ownership interest in OpCo and its subsidiaries as a noncontrolling interest in the unaudited condensed consolidated financial statements.

Cash Distributions Paid and Declared. We paid the following per-unit distributions during the three and nine months ended September 30:

	Three months ended September 30,				Nine months ended September 30,
	2018		2017		2018		2017
Per-unit distributions to unitholders	$	0.575	$	0.575	$	1.725	$	1.725

On October 25, 2018, the Board of Directors of our General Partner declared a distribution of $0.575 per unit for the quarterly period ended September 30, 2018. This distribution, which totaled $45.2 million, will be paid on November 14, 2018 to unitholders of record at the close of business on November 7, 2018.

Incentive Distribution Rights. Our general partner also currently holds IDRs that entitle it to receive increasing percentage allocations, up to a maximum of 50%, of the cash we distribute from operating surplus in excess of $0.46 per unit per quarter. Our payment of IDRs as reported in distributions to unitholders – general partner in the statement of partners' capital during the three and nine months ended September 30 follow.

	Three months ended September 30,				Nine months ended September 30,
	2018		2017		2018		2017
	(In thousands)
IDR payments	$	2,136	$	2,127	$	6,400	$	6,333

For the purposes of calculating net income attributable to General Partner in the statements of operations and partners' capital, the financial impact of IDRs is recognized in respect of the quarter for which the distributions were declared. For the purposes of calculating distributions to unitholders in the statements of partners' capital and cash flows, IDR payments are recognized in the quarter in which they are paid.