9.	Stock-Based Compensation

We recognize stock-based compensation expense for all equity-based awards issued to employees, directors and non-employees that are expected to vest. Stock-based compensation expense is based on the fair value of awards as of the grant date. We recognized $147 thousand and $570 thousand of stock-based compensation expense related to equity awards for the three months ended March 31, 2020 and 2019, respectively, under the fair value method. In addition to the stock-based compensation expense recognized, we also recognized $(6) thousand and $27 thousand of expense related to the change in the fair value of cash-settled restricted stock units (RSUs) during the three months ended March 31, 2020 and 2019, respectively.

During the three months ended March 31, 2020, we granted 30,000 time-vesting RSUs to employees with an aggregate fair value of approximately $21 thousand. During the three months ended March 31, 2019, the Company granted approximately 300,000 time-vesting RSUs to employees with an aggregate fair value of approximately $800 thousand. A portion of the time-vesting RSUs vest quarterly in equal amounts over the course of eight quarters, and the remainder vest annually in equal amounts over the course of three years. The fair value of the time-vesting RSUs is expensed ratably over the requisite service period, which ranges from one year to three years.

Our 1995 long-term incentive program (LTIP) provides for the issuance of performance-vesting and time-vesting restricted stock units to certain executives and other employees. Vesting of the performance-vesting restricted stock units (PRSU's) is contingent upon the employee's continued employment, and our achievement of certain performance goals during designated performance period as established by the Compensation Committee of the Board of Directors. We recognize compensation expense, net of estimated forfeitures, for PRSU's on a straight-line basis, over the performance period and based on the probable outcome of achievement of the financial targets. At the end of each reporting period, the Company estimates the number of PRSUs that are expected to vest, based on the probability and extent to which the performance goals will be met, to determine the expense for the period. If the number of shares expected to be earned changes during the period of performance, we make a cumulative adjustment to compensation expense based on the revised number of shares expected to vest.

During the three months ended March 31, 2020, we granted approximately 510,000 performance-vesting RSUs to key employees with an aggregate fair value of approximately $600 thousand. These awards vest over three years based upon certain financial metrics achieved during fiscal 2022. Approximately 50% of these awards are based upon obtaining certain revenue targets, and the remainder are based upon achieving certain Adjusted EBITDA targets. During the three months ended March 31, 2019, we granted approximately 350,000 performance-vesting RSUs. These awards vest over three years based upon achieving certain financial metrics during 2021 for revenue and Adjusted EBITDA.

We did not any grant stock options for the three months ended March 31, 2020 or 2019.