Deferred Costs and Other Contract Assets

Deferred costs and other contract assets consist of the following (in thousands):



	September 29, 2018		December 30, 2017 As Adjusted
Deferred cost of goods sold	$	105,664	$	93,261
Prepaid contract incentives	5,485		6,115
Deferred commissions	4,950		5,613
Unbilled contract receivables	3,424		4,267
Deferred costs and other contract assets	$	119,523	$	109,256

For the three months ended September 29, 2018 and September 30, 2017, $7.4 million and $7.6 million, respectively, of deferred cost of goods sold was amortized to cost of goods sold. For the nine months ended September 29, 2018 and September 30, 2017, $22.2 million and $21.5 million, respectively, of deferred costs of goods sold was amortized to cost of goods sold.

For the three months ended September 29, 2018 and September 30, 2017, $0.5 million and $0.6 million, respectively, of prepaid contract incentives was amortized as a reduction to revenue. For the nine months ended September 29, 2018 and September 30, 2017, $1.3 million and $1.5 million, respectively, of prepaid contract incentives was amortized as a reduction to revenue.

For the three months ended September 29, 2018 and September 30, 2017, $0.5 million and $0.6 million, respectively, of deferred commissions was amortized to selling, general and administrative expenses. For the nine months ended September 29, 2018 and September 30, 2017, $1.6 million and $1.9 million, respectively, of deferred commissions was amortized to selling, general and administrative expenses.