Stock-Based Compensation

12 Months Ended

Dec. 31, 2023

Share-Based Payment Arrangement [Abstract]

STOCK-BASED COMPENSATION

The Company's Board of Directors has granted stock incentive awards to certain employees and board members pursuant to a long term incentive plan which was approved by the Company's stockholders in May 2005 and in May 2015. Employees have been awarded non-vested stock units with performance conditions, non-vested stock units with market conditions and non-vested restricted stock. The restrictions on the non-vested restricted stock awards lapse at the end of a specified service period, which is typically three years from the date of grant. Restrictions could lapse sooner upon a business combination, death, disability or after an employee qualifies for retirement. The non-vested stock units will be converted into a number of shares of Company stock depending on performance and market conditions at the end of a specified service period, lasting approximately three years. The performance condition awards will be converted into a number of shares of Company stock based on the Company's average return on invested capital during the service period. Similarly, the market condition awards will be converted into a

number of shares depending on the appreciation of the Company's stock compared to the Nasdaq Transportation Index. Board members have been granted time-based awards that vest after a period of twelve months. The Company expects to settle all of the stock unit awards by issuing new shares of stock. The table below summarizes award activity.


	Year Ended December 31
	2023			2022			2021
	Number of Awards	Weighted average grant-date fair value		Number of Awards	Weighted average grant-date fair value		Number of Awards	Weighted average grant-date fair value
Outstanding at beginning of period	929,205	$	21.83	978,188	$	17.49	1,085,023	$	17.14
Granted	661,396	20.46		292,577	35.19		273,845	26.65
Converted	(374,267)	23.07		(327,160)	20.43		(316,430)	22.76
Expired	(117,550)	24.12		(3,000)	40.02		(58,650)	24.79
Forfeited	(32,000)	24.71		(11,400)	27.44		(5,600)	23.31
Outstanding at end of period	1,066,784	$	20.19	929,205	$	21.83	978,188	$	17.49
Vested	501,810	$	12.94	497,128	$	13.05	414,949	$	11.43

The average grant-date fair value of each performance condition award, non-vested restricted stock award and time-based award granted by the Company was $20.78, $33.84 and $26.69 for 2023, 2022 and 2021, respectively, the fair value of the Company’s stock on the date of grant. The average grant-date fair value of each market condition award granted was $23.28, $46.20 and $26.50 for 2023, 2022 and 2021, respectively. The market condition awards were valued using a Monte Carlo simulation technique based on volatility over three years for the awards granted in 2023, 2022 and 2021 using daily stock prices and using the following variables:


	2023	2022	2021
Risk-free interest rate	3.7%	2.5%	0.3%
Volatility	37.1%	38.3%	39.7%

For the years ended December 31, 2023, 2022 and 2021, the Company recorded expense of $8.5 million, $8.3 million and $7.4 million, respectively, for stock incentive awards. At December 31, 2023, there was $9.9 million of unrecognized expense related to the stock incentive awards that is expected to be recognized over a weighted-average period of 1.5 years. As of December 31, 2023, none of the awards were convertible, 430,363 units of the Board members' time-based awards had vested and none of the outstanding shares of the restricted stock had vested. These awards could result in a maximum number of 1,341,559 additional outstanding shares of ATSG's common stock depending on service, performance and market results through December 31, 2025.