As of September 30, 2022, the 2005 Incentive Plan, as amended, has a total reserve of 27,783,379 shares of which 3,757,122 shares are available for issuance.

The stock-based compensation related to our stock-based awards and employee stock purchase plan for the three and nine months ended September 30, 2022 and 2021 is as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2022		2021		2022		2021
Cost of net revenues	$	1,651	$	1,451	$	4,779	$	4,175
Selling, general and administrative	25,293		22,229		76,509		67,131

Research and development	5,974		4,722		17,391		13,192
Total stock-based compensation	$	32,918	$	28,402	$	98,679	$	84,498

The fair value of RSUs is based on our closing stock price on the date of grant. RSUs granted generally vest over a period of four years. A summary for the nine months ended September 30, 2022 is as follows:


	Number of Shares Underlying RSUs (in thousands)	Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)
Unvested as of December 31, 2021	492	$	369.17
Granted	239	478.94
Vested and released	(196)	334.10
Forfeited	(35)	433.42
Unvested as of September 30, 2022	500	$	430.73	1.4	$	103,619

As of September 30, 2022, we expect to recognize $154.1 million of total unamortized compensation costs, net of estimated forfeitures, related to RSUs over a weighted average period of 2.4 years.

We grant MSUs to members of senior management. Each MSU represents the right to one share of Align’s common stock. The actual number of MSUs which will be eligible to vest will be based on the performance of Align’s stock price relative to the performance of a stock market index over the vesting period. MSUs vest over a period of three years and the maximum number eligible to vest in the future is 250% of the MSUs initially granted.

The following table summarizes the MSU performance for the nine months ended September 30, 2022:


	Number of Shares Underlying MSUs (in thousands)	Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)
Unvested as of December 31, 2021	174	$	551.57
Granted 1	101	607.96
Vested and released	(128)	396.10
Forfeited	(3)	744.39
Unvested as of September 30, 2022	144	$	725.73	1.2	$	29,838

1 Includes MSUs vested during the period above 100% of the grant as actual shares released is based on Align’s stock performance over the vesting period.

As of September 30, 2022, we expect to recognize $47.7 million of total unamortized compensation costs, net of estimated forfeitures, related to MSUs over a weighted average period of 1.2 years.

As of September 30, 2022, we have 2,108,898 shares available for future issuance under our Amended and Restated 2010 Employee Stock Purchase Plan (the “2010 Purchase Plan”).

The fair value of the option component of the 2010 Purchase Plan shares was estimated at the grant date using the Black-Scholes option pricing model with the following weighted average assumptions:


	Three Months Ended September 30,						Nine Months Ended September 30,
	2022			2021			2022			2021
Expected term (in years)	1.5			1.2			1.5			1.1
Expected volatility	52.3		%	51.1		%	50.2		%	52.7		%
Risk-free interest rate	2.9		%	0.1		%	1.8		%	0.1		%
Expected dividends	—			—			—			—
Weighted average fair value at grant date	$	112.84		$	257.89		$	159.44		$	246.84

As of September 30, 2022, we expect to recognize $22.0 million of total unamortized compensation costs related to future employee stock purchases over a weighted average period of 1.1 years.