3. Revenue

Disaggregated revenue

The following table disaggregates revenue by service (in thousands):


	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2019		2018		2019		2018

Fertility benefit services revenue	$	50,024	$	26,389	$	136,085	$	72,004
Pharmacy benefit services revenue		11,172		1,409		28,476		4,209
Total revenue	$	61,196	$	27,798	$	164,561	$	76,213

Concentration of Major Clients

For the nine months ended September 30, 2019 and 2018, each of our largest four clients represented 10% or more of our total revenue. One of our clients accounted for 16% and 24%, respectively. Another client accounted for 10% and 15%, respectively. A third client accounted for less than 10% and 10%, respectively. Lastly, a fourth client accounted for 12% for the nine months ended September 30, 2019.

There are no material contract asset or contract liability balances as of September 30, 2019 and December 31, 2018.