SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)

12 Months Ended

Dec. 31, 2016

The following table sets forth the aging of our net accounts receivable (net of allowance for contractual adjustments and prior to allowance for doubtful accounts), aged based on date of service and categorized based on the three primary overall types of accounts receivable characteristics (in thousands):



	December 31, 2016							December 31, 2015
	0 - 180 days		Over 180 days		Total			0 - 180 days		Over 180 days		Total
Government	$	19,891	$	8,278	$	28,169		$	19,944	$	11,369	$	31,313
Commercial	97,744		19,848		117,592			94,477		20,213		114,690
Patient	3,955		6,825		10,780			5,014		6,025		11,039
Gross accounts receivable	$	121,590	$	34,951	156,541			$	119,435	$	37,607	157,042
Allowance for doubtful accounts					(44,730		)					(59,689		)
Net accounts receivable					$	111,811						$	97,353

Estimated useful lives of assets

Property and equipment is stated at cost less accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated useful lives of assets as follows:



Asset	Useful Life
Computer hardware and software	3	years	-	5	years
Office equipment				5	years
Vehicles	4	years	-	5	years
Medical equipment	13	months	-	5	years
Furniture and fixtures				5	years