15.

EQUITY-BASED COMPENSATION

The Partnership has granted equity-based compensation awards to Blackstone’s senior managing directors, non-partner professionals, non-professionals and selected external advisers under the Partnership’s 2007 Equity Incentive Plan (the “Equity Plan”), the majority of which to date were granted in connection with Blackstone’s initial public offering (“IPO”). The Equity Plan allows for the granting of options, unit appreciation rights or other unit-based awards (units, restricted units, restricted common units, deferred restricted common units, phantom restricted common units or other unit-based awards based in whole or in part on the fair value of the Blackstone common units or Blackstone Holdings Partnership Units) which may contain certain service or performance requirements. As of January 1, 2018, the Partnership had the ability to grant 172,155,134 units under the Equity Plan.

For the three months ended March 31, 2018 and March 31, 2017, the Partnership recorded compensation expense of $92.2 million and $91.3 million, respectively, in relation to its equity-based awards with corresponding tax benefits of $14.5 million and $14.1 million, respectively.

As of March 31, 2018, there was $944.6 million of estimated unrecognized compensation expense related to unvested awards. This cost is expected to be recognized over a weighted-average period of 4.2 years.

Total vested and unvested outstanding units, including Blackstone common units, Blackstone Holdings Partnership Units and deferred restricted common units, were 1,205,550,044 as of March 31, 2018. Total outstanding unvested phantom units were 44,850 as of March 31, 2018.

A summary of the status of the Partnership’s unvested equity-based awards as of March 31, 2018 and of changes during the period January 1, 2018 through March 31, 2018 is presented below:


	Blackstone Holdings					The Blackstone Group L.P.
						Equity Settled Awards					Cash Settled Awards
Unvested Units	Partnership Units			Weighted- Average Grant Date Fair Value		Deferred Restricted Common Units and Options			Weighted- Average Grant Date Fair Value		Phantom Units			Weighted- Average Grant Date Fair Value
Balance, December 31, 2017		30,023,189		$	35.26		9,019,974		$	30.03		44,196		$	31.85
Granted		1,976,399			32.02		3,248,577			32.52		117			33.43
Vested		(2,091,413	)		36.64		(3,240,593	)		30.51		(151	)		32.99
Forfeited		—			—		(59,235	)		30.20		—			—

Balance, March 31, 2018		29,908,175		$	34.95		8,968,723		$	30.74		44,162		$	33.16

Units Expected to Vest

The following unvested units, after expected forfeitures, as of March 31, 2018, are expected to vest:


	Units		Weighted-Average Service Period in Years
Blackstone Holdings Partnership Units		26,046,981		3.7
Deferred Restricted Blackstone Common Units		7,729,930		2.3

Total Equity-Based Awards		33,776,911		3.4

Phantom Units		36,235		2.7