The Company issues stock-based awards, including stock options, restricted stock and restricted stock units, to certain officers, employees and non-employee directors under the Acadia Healthcare Company, Inc. Incentive Compensation Plan (the “Equity Incentive Plan”). At June 30, 2022, a maximum of 12,700,000 shares of the Company’s common stock were authorized for issuance as stock options, restricted stock and restricted stock units or other share-based compensation under the Equity Incentive Plan, of which 3,110,264 were available for future grant. Stock options may be granted for terms of up to 10 years. The Company recognizes expense on all share-based awards on a straight-line basis over the requisite service period of the entire award. Grants to employees generally vest in annual increments of 25% each year, commencing one year after the date of grant. The exercise prices of stock options are equal to the most recent closing price of the Company’s common stock on the most recent trading date prior to the date of grant.

The Company recognized $6.6 million and $9.0 million in equity-based compensation expense for the three months ended June 30, 2022 and 2021 and $14.5 million and $16.1 million for the six months ended June 30, 2022 and 2021, respectively. At June 30, 2022, there was $71.2 million of unrecognized compensation expense related to unvested options, restricted stock and restricted stock units, which is expected to be recognized over the remaining weighted average vesting period of 1.5 years.

The Company recognized a deferred income tax benefit of $1.9 million and $2.3 million for the three months ended June 30, 2022 and 2021, respectively, related to equity-based compensation expense. The Company recognized a deferred income tax benefit of $3.9 million and $4.1 million for the six months ended June 30, 2022 and 2021.

	Number of Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Options outstanding at January 1, 2021		1,510,306		$	37.56		7.35	$	1,414
Options granted		324,320			57.53		9.31		851
Options exercised		(558,322	)		39.45	N/A			11,118
Options cancelled		(170,235	)		40.08	N/A		N/A
Options outstanding at December 31, 2021		1,106,069			42.07		7.49		19,988
Options granted		310,320			53.87		9.67		3,157
Options exercised		(179,811	)		38.40	N/A			4,963
Options cancelled		(96,165	)		46.30	N/A		N/A
Options outstanding at June 30, 2022		1,140,413		$	45.51		7.74	$	21,112
Options exercisable at December 31, 2021		324,409		$	43.24		5.48	$	5,575
Options exercisable at June 30, 2022		387,978		$	42.30		5.97	$	8,453

Fair values are estimated using the Black-Scholes option pricing model. The following table summarizes the grant-date fair value of options and the assumptions used to develop the fair value estimates for options granted during the six months ended June 30, 2022 and year ended December 31, 2021:

	June 30, 2022			December 31, 2021
Weighted average grant-date fair value of options	$	19.77		$	20.64
Risk-free interest rate		1.9	%		0.9	%
Expected volatility		39	%		40	%
Expected life (in years)		5.0			5.0

The Company’s estimate of expected volatility for stock options is based upon the volatility of its stock price over the expected life of the award. The risk-free interest rate is the approximate yield on U.S. Treasury Strips having a life equal to the expected option life on the date of grant. The expected life is an estimate of the number of years an option will be held before it is exercised.

	Number of Shares			Weighted Average Grant-Date Fair Value
Unvested at January 1, 2021		1,022,996		$	28.41
Granted		352,430			58.32
Cancelled		(82,751	)		39.63
Vested		(366,048	)		30.81
Unvested at December 31, 2021		926,627		$	37.84
Granted		554,618			62.08
Cancelled		(81,250	)		46.53
Vested		(340,499	)		31.46
Unvested at June 30, 2022		1,059,496		$	51.91

	Number of Units			Weighted Average Grant-Date Fair Value
Unvested at January 1, 2021		1,073,062		$	20.15
Granted		149,416			61.52
Performance adjustment		465,993			25.49
Cancelled		—			—
Vested		(184,051	)		42.30
Unvested at December 31, 2021		1,504,420		$	23.20
Granted		105,311			73.96
Performance adjustment		125,384			31.39
Cancelled		—			—
Vested		(518,474	)		43.16
Unvested at June 30, 2022		1,216,641		$	19.94

Restricted stock awards are time-based vesting awards that vest over a period of three or four years and are subject to continuing service of the employee or non-employee director over the ratable vesting periods. The fair values of the restricted stock awards were determined based on the closing price of the Company’s common stock on the trading date immediately prior to the grant date.

Restricted stock units are granted to employees and are subject to Company performance compared to pre-established targets. In addition to Company performance, these performance-based restricted stock units are subject to the continuing service of the employee during the three-year period covered by the awards. The performance condition for the restricted stock units is based on the Company’s achievement of annually established targets for diluted earnings per share. The number of shares issuable at the end of the applicable vesting period of restricted stock units ranges from 0% to 200% of the targeted units based on the Company’s actual performance compared to the targets.

The fair values of restricted stock units were determined based on the closing price of the Company’s common stock on the trading date immediately prior to the grant date for units subject to performance conditions.