The Perdoceo Education Corporation Amended and Restated 2016 Incentive Compensation Plan (the “2016 Plan”) became effective (as the Career Education Corporation 2016 Incentive Compensation Plan) on May 24, 2016, and the amendment and restatement of the 2016 Plan became effective on June 3, 2021, upon its approval by the Company’s stockholders. Under the 2016 Plan, Perdoceo may grant to eligible participants awards of stock options, stock appreciation rights, restricted stock, restricted stock units, deferred stock, performance units, annual incentive awards, and substitute awards, which generally may be settled in cash or shares of our common stock. The vesting of all types of awards is subject to possible acceleration in certain circumstances. If a plan participant terminates employment for any reason other than by death or disability during the vesting period, the right to unvested awards is generally forfeited.

For the years to date ended September 30, 2021 and 2020, the Company granted approximately 0.4 million and 0.3 million restricted stock units, respectively, which are not “performance-based” and which have a grant-date fair value of approximately $4.4 million for each period.

Additionally, for the years to date ended September 30, 2021 and 2020, the Company granted approximately 0.4 million and 0.3 million restricted stock units, respectively, which are “performance-based” and which have a grant-date fair value of approximately $4.2 million and $3.9 million, respectively. The performance-based restricted stock units are subject to performance conditions which are determined at the time of grant and typically cover a three-year performance period. These performance conditions may result in all units being forfeited even if the requisite service period is met.

There were no restricted stock units granted during each of the quarters ended September 30, 2021 and 2020.

All restricted stock units granted in 2020 and 2021 are to be settled in shares of our common stock.

There were no stock options granted during each of the quarters or years to date ended September 30, 2021 and 2020.

Total share-based compensation expense for the quarters and years to date ended September 30, 2021 and 2020 for all types of awards was as follows (dollars in thousands):

	For the Quarter Ended September 30,				For the Year to Date Ended September 30,
Award Type	2021		2020		2021		2020
Stock options	$	101	$	265	$	357	$	963
Restricted stock units settled in stock		3,752		2,962		10,917		8,759
Restricted stock units settled in cash		-		-		-		(240	)
Total share-based compensation expense	$	3,853	$	3,227	$	11,274	$	9,482

As of September 30, 2021, we estimate that compensation expense of approximately $17.0 million will be recognized over the next four years for all unvested share-based awards that have been granted to participants. This amount excludes any estimates of forfeitures.