See the Form 10-K for a detailed description of the Company’s stock-based compensation awards, including information related to vesting terms and service and performance conditions.

The following table summarizes restricted stock awards activity for the three months ended March 31, 2019:

	Time-Based					Market-Based
	Restricted Stock Awards					Restricted Stock Awards
	Shares			Weighted Average Grant Date Fair Value		Shares			Weighted Average Grant Date Fair Value
Unvested shares of restricted stock outstanding at December 31, 2018		806,469		$	67.54		—		$	—
Granted		239,109		$	131.88		280,960		$	102.76
Vested		—			—		(280,408	)	$	102.76
Forfeited		(20,083	)	$	71.66		(552	)	$	102.57
Unvested shares of restricted stock outstanding at March 31, 2019		1,025,495		$	82.46		—		$	—

In January 2019, we issued an aggregate of 520,069 restricted shares of common stock to our executive officers, certain non-executive, non-sales employees and non-executive sales management employees under the Paycom Software, Inc. 2014 Long-Term Incentive Plan (the “LTIP”), consisting of 280,960 shares subject to market-based vesting conditions (“Market-Based Shares”) and 239,109 shares subject to time-based vesting conditions (“Time-Based Shares”). Market-Based Shares vested 50% on the first date that the Company’s total enterprise value (“TEV”) (calculated as defined in the applicable restricted stock award agreement) equaled or exceeded $8.65 billion and 50% on the first date that the Company’s TEV equaled or exceeded $9.35 billion, in each case provided that (i) such date occurred on or before the sixth anniversary of the grant date and (ii) the recipient was employed by, or providing services to, the Company on the applicable vesting date. As shown in the table below, all Market-Based Shares issued during the three months ended March 31, 2019 have vested.

The following table summarizes vesting activity for Market-Based Shares during the three months ended March 31, 2019, the associated compensation cost recognized in connection with each vesting event and the number of shares withheld to satisfy tax withholding obligations:

Vesting Condition	Date Vested	Number of Shares Vested		Compensation Cost Recognized Upon Vesting	Shares Withheld for Taxes¹
Market-based (TEV = $8.65 billion)	February 13, 2019		140,218	$14.9 million		54,507
Market-based (TEV = $9.35 billion)	February 22, 2019		140,190	$13.9 million		55,547

Time-Based Shares granted to certain non-executive employees in January 2019 will vest 25% on a specified initial vesting date and 25% on each of the first three anniversaries of such initial vesting date, provided that the recipient is employed by, or providing services to, the Company or a subsidiary on the applicable vesting date. Time-Based Shares granted to executive officers, sales management employees and certain non-executive employees will vest in three equal annual tranches beginning on a specified initial vesting date and thereafter on the first and second anniversaries of such date, provided that the executive officer or employee is employed by, or providing services to, the Company on the applicable vesting date.

For the three months ended March 31, 2019 and 2018, our total compensation expense related to restricted stock was $31.1 million and $23.4 million, respectively. There was $62.9 million of unrecognized compensation cost, net of estimated forfeitures, related to unvested shares of restricted stock outstanding as of March 31, 2019. The unrecognized compensation cost for the unvested shares is expected to be recognized over a weighted average period of 1.9 years as of March 31, 2019.

We capitalized stock-based compensation costs related to software developed for internal use of $3.3 million and $2.5 million for the three months ended March 31, 2019 and 2018, respectively.