REVENUE

We classify revenue in three categories: service revenue, revenue from reimbursable expenses and non-controlling interests. Service revenue consists of amounts attributable to our fee-based services and sales of short-term investments in real estate. Reimbursable expenses and non-controlling interests are pass-through items for which we earn no margin. Reimbursable expenses consist of amounts we incur on behalf of our customers in performing our fee-based services that we pass directly on to our customers without a markup. Non-controlling interests represent the earnings of Lenders One, a consolidated entity that is a mortgage cooperative managed, but not owned, by Altisource. Lenders One is included in revenue and reduced from net income to arrive at net income attributable to Altisource (see Note 1). Our services are primarily provided to customers located in the United States. The components of revenue were as follows for the three months ended March 31:



(in thousands)	2019		2018

Service revenue	$	164,999	$	188,766
Reimbursable expenses	4,496		8,147
Non-controlling interests	440		525

Total	$	169,935	$	197,438

Disaggregation of Revenue

Disaggregation of total revenues by major source is as follows:



(in thousands)	Revenue recognized when services are performed or assets are sold		Revenue related to technology platforms and professional services		Reimbursable expenses revenue		Total revenue

Three months ended March 31, 2019	$	147,755	$	17,684	$	4,496	$	169,935
Three months ended March 31, 2018	166,956		22,335		8,147		197,438

Contract Balances

Our contract assets consist of unbilled accounts receivable (see Note 5). Our contract liabilities consist of current deferred revenue as reported on the accompanying condensed consolidated balance sheets and non-current deferred revenue (see Note 13). Revenue recognized that was included in the contract liability at the beginning of the period, including amounts added to the contract liability as part of the cumulative effect of adopting Topic 606, was $4.9 million and $5.9 million for the three months ended March 31, 2019 and 2018, respectively.