Our 2019 Long-Term Equity Compensation Plan, which was approved by our shareholders in May 2019, permits the granting of restricted stock units and certain other forms of equity awards to officers and other key employees. Under this plan, we also grant each non-management director deferred stock units, which permit non-management directors to receive, at a later date, one share of Rogers capital stock for each deferred stock unit, with no payment of any consideration by the director at the time the shares were received.


	As of December 31,
	2020	2019
Shares reserved for issuance under outstanding restricted stock unit awards	324,260	315,571
Deferred compensation to be paid in stock, including deferred stock units	12,715	7,681
Additional shares reserved for issuance under Rogers Corporation 2019 Long-Term Equity Compensation Plan	918,809	1,063,920
Shares reserved for issuance under the Rogers Corporation Global Stock Ownership Plan for Employees	78,678	91,670
Total	1,334,462	1,478,842

As of December 31, 2020, we had performance-based restricted stock units from 2020, 2019 and 2018 outstanding. These awards generally cliff vest at the end of a three-year measurement period. However, employees whose employment terminates during the measurement period due to death, disability, or, in certain cases, retirement may receive a pro-rata payout based on the number of days they were employed during the measurement period. Participants are eligible to be awarded shares ranging from 0% to 200% of the original award amount, based on certain defined performance measures.

The outstanding awards have one measurement criteria: the three-year total shareholder return (TSR) on our capital stock as compared to that of a specified group of peer companies. The TSR measurement criteria of the awards is considered a market condition. As such, the fair value of this measurement criteria is determined on the grant date using a Monte Carlo simulation valuation model. We recognize compensation expense on all of these awards on a straight-line basis over the vesting period with no changes for final projected payout of the awards. We account for forfeitures as they occur.


	February 12, 2020	June 3, 2019	February 7, 2019	September 17, 2018	February 8, 2018
Expected volatility	41.0%	39.7%	36.7%	36.6%	34.8%
Expected term (in years)	2.9	2.6	2.9	3.0	3.0
Risk-free interest rate	1.41%	1.78%	2.43%	2.85%	2.28%

Risk-free interest rate – We use an implied “spot rate” yield on U.S. Treasury Constant Maturity rates as of the grant date for our assumption of the risk-free interest rate.


	2020			2019			2018
	Awards Outstanding	Weighted- Average Grant Date Fair Value		Awards Outstanding	Weighted- Average Grant Date Fair Value		Awards Outstanding	Weighted- Average Grant Date Fair Value
Awards outstanding as of January 1	106,943	$	161.33	142,434	$	110.19	169,202	$	97.16
Awards granted	87,244	131.99		112,160	114.22		75,760	163.55
Stock issued	(75,486)	111.54		(135,032)	69.10		(81,230)	131.72
Awards forfeited	(7,642)	179.89		(12,619)	152.22		(21,298)	114.40
Awards outstanding as of December 31	111,059	$	170.84	106,943	$	161.33	142,434	$	110.19

We recognized $5.8 million, $5.0 million and $4.4 million of compensation expense related to performance-based restricted stock units for the years ended December 31, 2020, 2019 and 2018, respectively. As of December 31, 2020, there was $7.6 million of total unrecognized compensation cost related to unvested performance-based restricted stock units. That cost is expected to be recognized over a weighted average period of 0.8 years.

As of December 31, 2020, we had time-based restricted stock unit awards from 2020, 2019 and 2018 outstanding. The outstanding awards all ratably vest on the first, second and third anniversaries of the original grant date. However, employees whose employment terminates during the measurement period due to death, disability, or, in certain cases, retirement may receive a pro-rata payout based on the number of days they were employed subsequent to the last grant anniversary date. Each time-based restricted stock unit represents a right to receive one share of the Rogers’ capital stock at the end of the vesting period. The fair value of the award is determined by the market value of the underlying stock price at the grant date. We recognize compensation expense on all of these awards on a straight-line basis over the vesting period. We account for forfeitures as they occur.


	2020			2019			2018
	Awards Outstanding	Weighted- Average Grant Date Fair Value		Awards Outstanding	Weighted- Average Grant Date Fair Value		Awards Outstanding	Weighted- Average Grant Date Fair Value
Awards outstanding as of January 1	101,685	$	122.68	117,476	$	116.10	173,331	$	69.10
Awards granted	58,807	116.87		62,115	126.92		46,810	143.93
Stock issued	(50,868)	111.16		(68,111)	81.53		(82,921)	84.92
Awards forfeited	(7,482)	122.87		(9,795)	116.52		(19,744)	112.06
Awards outstanding as of December 31	102,142	$	120.16	101,685	$	122.68	117,476	$	116.10

We recognized $6.0 million, $5.8 million and $5.6 million of compensation expense related to time-based restricted stock units for the years ended December 31, 2020, 2019 and 2018, respectively. As of December 31, 2020, there was $7.5 million of total unrecognized compensation cost related to unvested time-based restricted stock units. That cost is expected to be recognized over a weighted average period of 0.9 years.

We grant deferred stock units to non-management directors. These awards are fully vested on the date of grant and the related shares are generally issued on the 13-month anniversary of the grant date unless the individual elects to defer the receipt of those shares. Each deferred stock unit results in the issuance of one share of Rogers’ capital stock. The grant of deferred stock units is typically done annually during the second quarter of each year. The fair value of the award is determined by the market value of the underlying stock price at the grant date.


	2020			2019			2018
	Awards Outstanding	Weighted- Average Grant Date Fair Value		Awards Outstanding	Weighted- Average Grant Date Fair Value		Awards Outstanding	Weighted- Average Grant Date Fair Value
Awards outstanding as of January 1	7,150	$	170.89	8,400	$	108.86	9,250	$	109.48
Awards granted	10,400	108.88		5,950	183.40		8,400	108.86
Stock issued	(5,100)	183.40		(7,200)	108.86		(9,250)	109.48
Awards outstanding as of December 31	12,450	$	113.96	7,150	$	170.89	8,400	$	108.86

We recognized compensation expense related to deferred stock units of $1.1 million, $1.1 million and $0.9 million, for the years ended December 31, 2020, 2019 and 2018, respectively.