Incentive Plans

Stock-based compensation

For the three months ended March 31, 2015, the Company recorded $29 million of stock-based compensation expense for all plans, as compared to $31 million for the same period of 2014. As of March 31, 2015, there was $200 million of unrecognized compensation expense related to unvested share-based compensation plan awards, including $44 million attributable to stock-based awards that are expected to be settled on their vesting date in cash, rather than in equity shares ("Liability Awards"). The unrecognized compensation expense will be recognized over the remaining vesting periods of the awards, which is a period of less than three years on a weighted average basis. As of March 31, 2015 and December 31, 2014, accounts payable – due to affiliates includes $6 million and $23 million, respectively, of liabilities attributable to Liability Awards.

The following table summarizes the activity that occurred during the three months ended March 31, 2015, for each type of share-based incentive award issued by Pioneer:



	Restricted Stock Equity Awards		Restricted Stock Liability Awards		Performance Units	Stock Options
Outstanding as of December 31, 2014	1,233,539		328,087		154,733	199,058
Awards granted	422,966		158,726		82,431	—
Awards vested	(476,698	)	(160,751	)	—	—
Awards forfeited	(3,624	)	(7,233	)	—	—
Outstanding as of March 31, 2015	1,176,183		318,829		237,164	199,058