At September 30, 2019, we have seven stock-based compensation plans under which grants were made and awards remained outstanding. No further awards may be granted under six of the plans: the 1996 Equity Incentive Plan (the 1996 EIP), the Amended and Restated 2000 Equity Incentive Plan (the 2000 EIP), the 2009 Equity Incentive Plan (the 2009 EIP), the 2013 Equity Incentive Plan (the 2013 EIP), the Deferred Fee Plan and the Directors’ Equity Plan. At September 30, 2019, there were approximately 5,667,000 shares authorized for grant and approximately 2,801,000 shares available for grant under the 2017 Equity Incentive Plan (the 2017 EIP and together with the 1996 EIP, the 2000 EIP, the 2009 EIP and the 2013 EIPS, the EIPs).

As of January 1, 2019, we had 497,000 outstanding performance shares under the Frontier Long Term Incentive Plan (the LTIP). The following summary presents information regarding LTIP target performance shares as of September 30, 2019 and changes during the nine months then ended with regard to LTIP shares awarded under the 2013 EIP and the 2017 EIP:



			Number of
			Shares
			(in thousands)
	Balance at January 1, 2019		497
	LTIP target performance shares granted, net		-
	LTIP target performance shares earned		(41)
	LTIP target performance shares forfeited		(20)
	Balance at September 30, 2019		436

For purposes of determining compensation expense, the fair value of each performance share is measured at the end of each reporting period and, therefore, will fluctuate based on the price of Frontier common stock as well as performance relative to the targets. For the nine months ended September 30, 2019 and 2018, we recognized net compensation expense, reflected in “Selling, general and administrative expenses,” of $3 million for the LTIP.

The following summary presents information regarding unvested restricted stock as of September 30, 2019 and changes during the nine months then ended with regard to restricted stock granted under the 2013 EIP and the 2017 EIP:



		Weighted
		Average
	Number of	Grant Date		Aggregate
	Shares	Fair Value		Fair Value
	(in thousands)	(per share)		(in millions)
Balance at January 1, 2019	1,858	$	16.02	$	4
Restricted stock granted	105	$	2.00	$	-
Restricted stock vested	(711)	$	21.78	$	(1)
Restricted stock forfeited	(19)	$	32.44
Balance at September 30, 2019	1,233	$	11.26	$	1

For purposes of determining compensation expense, the fair value of each restricted stock grant is estimated based on the closing price of a share of our common stock on the date of the grant. Total remaining unrecognized compensation cost associated with unvested restricted stock awards that is deferred at September 30, 2019 was $8 million, and the weighted average vesting period over which this cost is expected to be recognized is approximately 1 year.