Accounts Receivable

9 Months Ended

Sep. 30, 2021

2. Accounts Receivable

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

	September 30, 2021			December 31, 2020
Accounts receivable – commercial
Accounts receivable, gross	$	7,297		$	8,090
Wholesaler distribution fees and prompt pay discounts		(1,680	)		(1,205	)
Reserve for returns		(2,964	)		(2,667	)
Total accounts receivable – commercial, net		2,653			4,218
Accounts receivable – collaborations and services
Accounts receivable, gross		7,559			—
Allowance for doubtful accounts		(767	)		—
Total accounts receivable – collaborations and services, net		6,792			—
Total accounts receivable, net	$	9,445		$	4,218

As of September 30, 2021 and December 31, 2020, the allowance for doubtful accounts for accounts receivable – commercial was de minimis. The Company had three wholesale distributors representing approximately 87% of commercial accounts receivable as of September 30, 2021 and approximately 81% and 82% of gross sales for the three and nine months ended September 30, 2021, respectively.

As of September 30, 2021, the allowance for accounts receivable – collaborations and services was $0.8 million and was related to $1.5 million of accounts receivable for Vertice Pharma, a collaboration partner for the co-promotion of Thyquidity. The Company had one collaboration partner, United Therapeutics, that comprised approximately 79% of the collaboration and services accounts receivable as of September 30, 2021 and approximately 99% and 95% of gross sales from collaborations and services for the three and nine months ended September 30, 2021, respectively.