Long-Term Incentive Plan Units

LTIP Units held pursuant to the Company's incentive plans are generally exercisable by the holder at any time after vesting. Each unit is convertible into one common share. Costs associated with the LTIP Units issued under the Company's incentive plans are measured as of the grant date and expensed ratably over the vesting period. Total expense associated with LTIP Units issued under the Company's incentive plans for each of the three-month periods ended September 30, 2018 and 2017 was $0.1 million. Total expense associated with LTIP Units issued under the Company's incentive plans for each of the nine-month periods ended September 30, 2018 and 2017 was $0.3 million.

On March 7, 2018, the Company's Board of Directors authorized the issuance of 1,723 LTIP Units to certain of its partially dedicated employees pursuant to the Company's 2017 Equity Incentive Plan. These LTIP Units will vest and become non-forfeitable on March 7, 2019.

On September 12, 2018, the Company's Board of Directors authorized the issuance of 14,440 LTIP Units to certain of its directors pursuant to the Company's 2017 Equity Incentive Plan. These LTIP Units will vest and become non-forfeitable on September 11, 2019.

The below table details on the Company's unvested LTIP Units as of September 30, 2018:



Grant Recipient	Number of LTIP Units Granted	Grant Date	Vesting Date⁽¹⁾
Directors:
	14,440	September 12, 2018	September 11, 2019
Partially dedicated employees:
	1,723	March 7, 2018	March 7, 2019
	8,533	December 12, 2017	December 12, 2018
	5,886	December 12, 2017	December 12, 2019
	5,583	December 13, 2016	December 13, 2018
Total unvested LTIP Units at September 30, 2018	36,165


(1)	Date at which such LTIP Units will vest and become non-forfeitable.

The following table summarizes issuance and exercise activity of the Company's LTIP Units for the three-month periods ended September 30, 2018 and 2017:



	Three-Month Period Ended September 30, 2018					Three-Month Period Ended September 30, 2017
	Manager	Director/ Employee		Total		Manager	Director/ Employee		Total
LTIP Units Outstanding (6/30/2018 and 6/30/2017, respectively)	375,000	117,882		492,882		375,000	94,539		469,539
Granted	—	14,440		14,440		—	10,002		10,002
Exercised	—	(3,334	)	(3,334	)	—	(2,801	)	(2,801	)
LTIP Units Outstanding (9/30/2018 and 9/30/2017, respectively)	375,000	128,988		503,988		375,000	101,740		476,740
LTIP Units Vested and Outstanding (9/30/2018 and 9/30/2017, respectively)	375,000	92,823		467,823		375,000	71,430		446,430

The following table summarizes issuance and exercise activity of the Company's LTIP Units for the nine-month periods ended September 30, 2018 and 2017:



	Nine-Month Period Ended September 30, 2018					Nine-Month Period Ended September 30, 2017
	Manager	Director/ Employee		Total		Manager	Director/ Employee		Total
LTIP Units Outstanding (12/31/2017 and 12/31/2016, respectively)	375,000	116,159		491,159		375,000	94,539		469,539
Granted	—	16,163		16,163		—	10,002		10,002
Exercised	—	(3,334	)	(3,334	)	—	(2,801	)	(2,801	)
LTIP Units Outstanding (9/30/2018 and 9/30/2017, respectively)	375,000	128,988		503,988		375,000	101,740		476,740
LTIP Units Vested and Outstanding (9/30/2018 and 9/30/2017, respectively)	375,000	92,823		467,823		375,000	71,430		446,430

As of September 30, 2018, there were an aggregate of 1,891,606 common shares underlying awards, including LTIP Units, available for future issuance under the Company's 2017 Equity Incentive Plan.