Schedule II VALUATION AND QUALIFYING ACCOUNTS

12 Months Ended

Dec. 31, 2016

Schedule II VALUATION AND QUALIFYING ACCOUNTS

Schedule II VALUATION AND QUALIFYING ACCOUNTS

Schedule II

COGENT COMMUNICATIONS HOLDINGS, INC. AND SUBSIDIARIES

VALUATION AND QUALIFYING ACCOUNTS

(in thousands)

Description	Balance at Beginning of Period		Charged to Costs and Expenses		(Deductions)			Balance at End of Period
Allowance for doubtful service accounts receivable (deducted from accounts receivable)(a)
Year ended December 31, 2014	$	1,871	$	5,046	$	(5,210	)	$	1,707
Year ended December 31, 2015	$	1,707	$	4,756	$	(4,696	)	$	1,757
Year ended December 31, 2016	$	1,757	$	3,840	$	(3,863	)	$	1,734
Allowance for early termination fees (deducted from accounts receivable)
Year ended December 31, 2014	$	2,144	$	5,082	$	(5,678	)	$	1,548
Year ended December 31, 2015	$	1,548	$	7,455	$	(6,659	)	$	2,344
Year ended December 31, 2016	$	2,344	$	4,916	$	(5,515	)	$	1,745
Deferred tax valuation allowance
Year ended December 31, 2014	$	354,537	$	10,436	$	(19,723	)	$	345,250
Year ended December 31, 2015	$	345,250	$	1,058	$	(132,770	)	$	213,538
Year ended December 31, 2016	$	213,538	$	3,102	$	(6,300	)	$	210,340

(a)           Bad debt expense, net of recoveries, was approximately $2.8 million for the year ended December 31, 2016, $3.3 million for the year ended December 31, 2015 and $3.7 million for the year ended December 31, 2014.