Stock-Based Compensation

In connection with the approval of the Business Combination, the Del Taco Restaurants, Inc. 2015 Omnibus Incentive Plan (the “2015 Plan”) was approved by shareholders to offer eligible employees, directors and consultants cash and stock-based incentive awards. Awards under the 2015 Plan are generally not restricted to any specific form or structure and could include, without limitation, stock options, stock appreciation rights, restricted stock, restricted stock units, other stock-based awards, other cash-based compensation and performance awards. Under the plan, there were 3,300,000 shares of common stock reserved and authorized. At September 10, 2019, there were 593,384 shares of common stock available for grant under the 2015 Plan.

Stock-Based Compensation Expense

The total compensation expense related to the 2015 Plan was $1.3 million and $1.5 million for the twelve weeks ended September 10, 2019 and September 11, 2018, respectively and $4.6 million and $4.1 million for the thirty-six weeks ended September 10, 2019 and September 11, 2018, respectively.

Restricted Stock Awards

A summary of outstanding and unvested restricted stock activity as of September 10, 2019 and changes during the period from January 1, 2019 through September 10, 2019 are as follows:



	Shares		Weighted-Average Grant Date Fair Value
Nonvested at January 1, 2019	1,234,531		$	12.87
Granted	531,173		12.17
Vested	(520,835	)	12.04
Forfeited	(9,337	)	10.71
Nonvested at September 10, 2019	1,235,532		$	12.94

For the thirty-six weeks ended September 10, 2019 and September 11, 2018, the Company made payments of $2.6 million and $2.4 million, respectively, related to tax withholding obligations for the vesting of restricted stock awards in exchange for 204,494 and 168,484 shares withheld, respectively. As of September 10, 2019, there was $11.3 million of unrecognized stock compensation expense, net of estimated forfeitures, related to restricted stock awards that is expected to be recognized over a weighted-average remaining period of 2.8 years. The fair value of these awards was determined based on the Company’s stock price on the grant date.

Stock Options

A summary of stock option activity as of September 10, 2019 and changes during the period from January 1, 2019 through September 10, 2019 are as follows:



	Options		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term	Aggregate Intrinsic Value
					(in years)	(in thousands)
Options outstanding at January 1, 2019	453,250		$	11.74	5.0	$	77
Granted	5,000		10.43
Exercised	(12,000	)	10.05
Forfeited/Expired	(14,750	)	12.60
Options outstanding at September 10, 2019	431,500		$	11.74	4.3	$	271
Options exercisable at September 10, 2019	280,748		$	11.01	3.8	$	225
Options exercisable and expected to vest at September 10, 2019	403,541		$	11.63	4.3	$	265

The aggregate intrinsic value in the table above is the amount by which the current market price of the Company's stock exceeds the exercise price on January 1, 2019 and September 10, 2019, respectively.

As of September 10, 2019, there was $0.5 million of unrecognized stock compensation expense, net of estimated forfeitures, related to stock option grants which is expected to be recognized over a weighted-average remaining period of 2.2 years.