The maximum number of common units that may be delivered with respect to awards under the Plan is 1,505,000. Generally, the Plan provides for grants of restricted units, unit options, performance awards, phantom units, unit awards, unit appreciation rights, distribution equivalent rights, and other unit-based awards, with various limits and restrictions attached to these awards on a grant-by-grant basis. The Plan is administered by the Board or a committee thereof.

The Board may terminate or amend the Plan at any time with respect to any common units for which a grant has not yet been made. The Board also has the right to alter or amend the Plan or any part of the Plan from time to time, including increasing the number of common units that may be granted, subject to unitholder approval as required by the exchange upon which common units are listed at that time; however, no change in any outstanding grant may be made that would adversely affect the rights of a participant with respect to awards granted to a participant prior to the effective date of such amendment or termination, except that the Board may amend any award to satisfy the requirements of Section 409A of the Internal Revenue Code. The Plan will expire on the tenth anniversary of its approval, when common units are no longer available under the Plan for grants or upon its termination by the Board, whichever occurs first.

	Employees of Circle K						Directors
	Phantom Units			Phantom Performance Units			Phantom Units			Total
Nonvested at December 31, 2017		2,620			—			10,539			13,159
Granted		—			14,301			15,580			29,881
Forfeited		—			(694	)		—			(694	)
Vested/Redeemed		(1,793	)		—			(10,539	)		(12,332	)
Nonvested at December 31, 2018		827			13,607			15,580			30,014
Granted		—			14,712			18,481			33,193
Forfeited		—			(717	)		—			(717	)
Vested/Redeemed		(827	)		(27,602	)		(32,020	)		(60,449	)
Nonvested at December 31, 2019		—			—			2,041			2,041

The GP Purchase constitutes a change in control under the Partnership’s 2012 Incentive Award Plan and accelerated vesting of all outstanding equity-based awards under the Plan, converting such awards into the same number of common units of the Partnership.

The nonvested phantom units granted to non-employee directors of the Board as a portion of director compensation outstanding as of December 31, 2019, will vest in July 2020. These awards were accompanied by tandem distribution equivalent rights that entitle the holder to cash payments equal to the amount of unit distributions authorized to be paid to the holders of our common units.

Since we grant awards to non-employee directors of the Board, and since the grants may be settled in cash, unvested phantom units receive fair value variable accounting treatment. As such, they are measured at fair value at each balance sheet reporting date and the cumulative compensation cost recognized is classified as a liability, which is included in accrued expenses and other current liabilities on the consolidated balance sheet. The balance of the accrual was insignificant at December 31, 2019 and 2018.

We record equity-based compensation as a component of general and administrative expenses in the statements of income. Equity-based compensation expense was $0.9 million for 2019, which includes approximately $0.5 million of expense recognized upon the accelerated vesting of awards concurrent with the GP Purchase. Equity-based compensation expense was insignificant for 2018 and 2017.

Before the CST Merger was completed, CST granted equity-based awards of approximately 47,000 in the form of time vested restricted stock units of CST, stock options of CST and market share units of CST in 2017, which were granted to certain employees of CST for services rendered on our behalf. Equity-based compensation expense charged to us under the Circle K Omnibus Agreement amounted to $0.3 million, $0.3 million and $1.7 million for 2019, 2018 and 2017, respectively.

At the completion of the CST Merger, each CST stock option, restricted stock unit and market share unit that was outstanding immediately prior to the completion of the CST Merger, excluding the CST restricted stock units granted in February 2017, whether vested or unvested, became fully vested and converted into the right to receive a cash payment as defined in the CST Merger Agreement. The Partnership was allocated a $0.4 million charge upon the accelerated vesting of these awards, included in the expense amounts for 2017 set forth above.