4. Accounts Receivable and Net Revenue:

Accounts receivable, net consists of the following (in thousands):


	December 31,
	2018			2017
Gross accounts receivable	$	2,031,341		$	1,790,034
Allowance for contractual adjustments and uncollectibles		(1,489,069	)		(1,286,035	)

	$	542,272		$	503,999

Net revenue consists of the following (in thousands):


	Years Ended December 31,
	2018		2017		2016
Net patient service revenue	$	3,067,784	$	2,915,648	$	2,760,192
Hospital contract administrative fees		363,369		315,778		271,886
Management services and other		215,970		226,886		151,081

	$	3,647,123	$	3,458,312	$	3,183,159

The following is a summary of our payor mix, expressed as a percentage of net revenue, exclusive of administrative fees and revenue related to management services and other, for the periods indicated:


	Years Ended December 31,
	2018			2017			2016
Contracted managed care		70	%		70	%		70	%
Government		24	%		25	%		23	%
Other third-parties		4	%		4	%		6	%
Private-pay patients		2	%		1	%		1	%

		100	%		100	%		100	%

Accounts receivable of $542.3 million and $504.0 million at December 31, 2018 and 2017, respectively, consist primarily of amounts due from GHC Programs and third-party insurance payors for services provided by the Company’s affiliated physicians.

Net revenue of $3.6 billion, $3.5 billion and $3.2 billion for the years ended December 31, 2018, 2017 and 2016, respectively, consists primarily of gross billed charges for services provided by the Company’s affiliated physicians less an estimated allowance for contractual adjustments and uncollectibles to properly account for the anticipated differences between gross billed charge amounts and expected reimbursement amounts.

The Company’s contractual adjustments and uncollectibles as a percentage of gross patient service revenue vary slightly each year depending on several factors, including improved managed care contracting, changes in reimbursement from state Medicaid programs and other GHC Programs, shifts in the percentage of patient services being reimbursed under GHC Programs and annual price increases.

The Company’s annual price increases typically increase contractual adjustments as a percentage of gross patient service revenue. This increase is primarily due to Medicaid, Medicare and other GHC Programs that generally provide for reimbursements on a fee-schedule basis rather than on a gross charge basis. When the Company bills these programs, like other payors, on a gross-charge basis, it also increases its provision for contractual adjustments and uncollectibles by the amount of any price increase, resulting in a higher contractual adjustment percentage.

Some of the Company’s hospital agreements require hospitals to pay the Company administrative fees. Some agreements provide for fees if the hospital does not generate sufficient patient volume in order to guarantee that the Company receives a specified minimum revenue level. The Company also receives fees from hospitals for administrative services performed by its affiliated physicians providing medical director or other services at the hospital.

In addition, the Company generates revenue through its management services organization for services rendered under various coding and billing contracts. Contract terms are specific to each customer and may include a combination of a flat fee for coding of medical charts, a fixed fee per patient visit as well as a percentage of cash collections received by the providers. Revenue for flat and fixed fee arrangements is recognized in the month the coding occurs or the patient visit occurs. Revenue for percentage fees are recognized in the month that cash is collected for customers from payors.