In January 2021, we granted 485,753 LTIP Units with time-based vesting requirements ("Time-Based LTIP Units") to management and other employees with a weighted average grant-date fair value of $29.21 per unit that vest ratably over four years subject to continued employment. Compensation expense for these units is being recognized over a four-year period.

Additionally, in January 2021, we granted 163,065 fully vested LTIP Units, with a grant-date fair value of $29.54 per unit, to certain employees who elected to receive all or a portion of their cash bonus, related to 2020 service, as LTIP Units. Compensation expense totaling $4.8 million for these LTIP Units was recognized in 2020.

The aggregate grant-date fair value of these Time-Based LTIP Units and LTIP Units granted during the three months ended March 31, 2021 was $19.0 million. The LTIP Units were valued based on the closing common share price on the date of grant and the Time-Based LTIP Units were valued using Monte Carlo simulations. The following is a summary of the significant assumptions used to value the Time-Based LTIP Units:

In April 2021, as part of their annual compensation, we granted a total of 71,792 fully vested LTIP Units to non-employee trustees with an aggregate grant-date fair value of $1.9 million. The LTIP Units may not be sold while such trustee is serving on the Board of Trustees.

In January 2021, we granted 627,874 LTIP Units with performance-based vesting requirements ("Performance-Based LTIP Units") to management and other employees with a weighted average grant-date fair value of $15.14 per unit. Our Performance-Based LTIP Units have a three-year performance period. 50% of any Performance-Based LTIP Units that are earned vest at the end of the three-year performance period and the remaining 50% vest on the fourth anniversary of the date of grant, subject to continued employment. If, however, the Performance-Based LTIP Units do not achieve a positive absolute total shareholder return ("TSR") at the end of the three-year performance period, but satisfy the relative performance criteria thereof, 50% of the units that otherwise could have been earned will be forfeited, and the remaining units that are earned will vest if and when we achieve a positive TSR during the succeeding seven years, measured at the end of each quarter. In January 2021, the three-year performance period ended for the Performance-Based LTIP Units granted on February 2, 2018. Based on our relative performance and absolute TSR over the three-year performance period, 100% of the units granted were earned.

The aggregate grant-date fair value of the Performance-Based LTIP Units granted during the three months ended March 31, 2021 was $9.5 million, valued using Monte Carlo simulations. Compensation expense for the Performance-Based LTIP Units is being recognized over a four-year period. The following is a summary of the significant assumptions used to value the Performance-Based LTIP Units:

Beginning in 2021, certain non-executive employees were granted RSUs with time-based vesting requirements ("Time-Based RSUs") and RSUs with performance-based vesting requirements ("Performance-Based RSUs") as part of their annual compensation. Vesting requirements and compensation expense recognition for the Time-Based RSUs and the Performance-Based RSUs are identical to those of the Time-Based LTIP Units and Performance-Based LTIP Units. In January 2021, we granted 18,343 Time-Based RSUs with a weighted average grant-date fair value of $31.33 per unit, and 11,886 Performance-Based RSUs with a grant-date fair value of $15.14 per unit.

The aggregate grant-date fair value of the RSUs granted during the three months ended March 31, 2021 was $755,000. The Time-Based RSUs were valued based on the closing price on the date of grant and the Performance-Based RSUs were valued using Monte Carlo simulations with the same significant assumptions used to value the Performance-Based LTIP Units above.

(1)	Primarily comprising compensation expense for: (i) certain employees who have elected to receive all or a portion of any cash bonus earned in the form of fully vested LTIP Units, (ii) RSUs and (iii) our ESPP.

(2)	Represents share-based compensation expense for LTIP Units and OP Units issued in the Formation Transaction, which are subject to post-Combination employment obligations.

(3)	Represents equity awards issued related to our successful pursuit of Amazon's additional headquarters in National Landing.

(4)	Included in "General and administrative expense: Share-based compensation related to Formation Transaction and special equity awards" in the accompanying statements of operations.

As of March 31, 2021, we had $57.3 million of total unrecognized compensation expense related to unvested share-based payment arrangements, which is expected to be recognized over a weighted average period of 1.9 years.

In April 2021, our shareholders approved an amendment to the JBG SMITH 2017 Omnibus Share Plan (the "Plan") to increase the common shares reserved under the Plan by 8.0 million.