4.	Accounts Receivable and Significant Concentrations

Accounts receivable consist of the following by customer type in the table below as of the periods presented:

	MARCH 31,		DECEMBER 31,
	2017		2016

	(Unaudited)
Commercial	$	2,816,288	$	2,319,142
Government		4,315,360		3,178,362
Gross accounts receivable		7,131,648		5,497,504
Less: allowances for doubtful accounts		(345,264)		(344,411)

Accounts receivable, net	$	6,786,384	$	5,153,093

For the three month periods ended March 31, 2017 and 2016, respectively, the Company did not recognize any material provisions for bad debt or any material recoveries of commercial accounts receivable for which an allowance had been previously established. The Company has not historically maintained a bad debt reserve for its government customers as it has not experienced material or recurring bad debt charges and the nature and size of the contracts has not necessitated the Company’s establishment of such a bad debt reserve.

Significant Concentrations

Customers representing ten percent or more of consolidated trade accounts receivable are set forth in the table below as of the periods presented:

	MARCH 31,		DECEMBER 31,
	2017		2016
	As a % of		As a % of
Customer Name	Receivables		Receivables


	(Unaudited)
Department of Homeland Security (DHS)		54%		47%

Customers representing ten percent or more of consolidated revenues are set forth in the table below for each of the periods presented:

	THREE MONTHS ENDED
	MARCH 31,
	2017		2016
	As a % of		As a % of
Customer Name	Revenues		Revenues

	(Unaudited)
Department of Homeland Security (DHS)		59%		65%