The Company’s plan is to have broad-based, long-term programs intended to attract and retain talented employees and align stockholder and employee interests. To this end, compensation for our senior leadership team includes equity awards in the form of restricted stock units ("RSUs") and performance stock units ("PSUs"). We calculate the fair value of the RSUs and PSUs at grant date based on the closing market price of our common stock at the date of grant. The compensation expense is recognized on a straight-line basis over the requisite service period of the award. The number of PSUs granted depends on the Company's achievement of target performance goals, which may range from 0% to 200% of the target award amount. The PSUs vest ratably over three years including the one-year performance period. Upon vesting, each stock award is exchangeable for one share of the Company's common stock, with accrued dividends.

The Company recognized total stock-based compensation expense for PSUs and RSUs of $1.1 million and $0.8 million for the three months ended March 31, 2024 and 2023, respectively.

As of March 31, 2024, the total unrecognized compensation expense related to the non-vested portion of the Company's RSUs was $2.4 million, which is expected to be recognized over a weighted average period of 1.6 years. As of March 31, 2024, the total unrecognized compensation expense related to the non-vested portion of the Company's PSUs was $5.3 million, which is expected to be recognized over a weighted average period of 1.5 years.

The following table shows the number of stock awards that were granted and vested, during the three months ended March 31, 2024:


	Restricted Stock Units					Performance Stock Units
	Number of units			Weighted average grant date fair value		Number of units			Weighted average grant date fair value
Unvested units as of December 31, 2023		230,574		$	12.27		543,422		$	13.37
Granted		111,608			12.05		131,953			12.05
Vested - issued		(142,763	)		10.89		(210,156	)		12.15
Vested - unissued		(6,812	)		15.16		—			—
Unvested units as of March 31, 2024		192,607		$	13.07		465,219		$	13.54

On June 8, 2023 the Company filed Form S-8 to register 325,000 common stock shares, the total shares reserved for the ESPP. The Company then opened enrollment for the first offering period that started July 1, 2023 and continued through December 31, 2023. There are two six month offering periods each year starting January 1 and July 1, with the purchase date on the last business day of each offering period.

Under the ESPP, eligible employees (as defined in the ESPP) can purchase the Company’s common stock through accumulated payroll deductions. Eligible employees may purchase the Company’s common stock at 85% of the lower of the fair market value of the Company’s common stock on the first or last business day of each six month offering period. Eligible employees may contribute up to 10% of their eligible compensation. Under the ESPP, a participant may not accrue rights to purchase more than $25,000 worth of the Company’s common stock for each calendar year in which such right is outstanding.

Employees who elect to participate in the ESPP commence payroll withholdings that accumulate through the end of the respective period. In accordance with the guidance in Topic 718-50 – Compensation – Stock Compensation, the ability to purchase shares of the Company’s common stock for 85% of the lower of the price on the first day of the offering period or the last day of the offering period (i.e. the purchase date) represents an option and, therefore, the ESPP is a compensatory plan under this guidance. Accordingly, stock-based compensation expense is determined based on the option’s grant-date fair value as estimated by applying the Black Scholes option-pricing model and is recognized over the withholding period. The stock-based compensation expense related to the ESPP recognized during the three months ended March 31, 2024 was not material and no compensation expense was recognized in the three months ended March 31, 2023.

ESPP employee payroll contributions accrued as of March 31, 2024 and December 31, 2023 totaled $0.7 million and $0.9 million, respectively, and are included within "Accrued expenses" in the Condensed Consolidated Balance Sheets. Cash withheld via employee payroll deductions is presented in financing activities within "Other financing activities" on the Condensed Consolidated Statement of Cash Flows.