For the three months ended March 31, 2023 and 2022, the Company recorded $231.5 million and $188.8 million, respectively, of product revenues, net. Three individual customers accounted for 49%, 32% and 7% of product revenues, net, for the three months ended March 31, 2023 and 48%, 36% and 8% of product revenues, net, for the three months ended March 31, 2022. The Company considers there to be revenue concentration risks for regions where net product revenues exceed 10% of consolidated net product revenues. The concentration of the Company’s net product revenues within a particular region may have a material adverse effect on the Company’s revenues and results of operations if sales in the respective regions experience difficulties. For the three months ended March 31, 2023, net product revenues totaled $200.5 million and $31.0 million within the U.S. and the rest of the world, respectively, with no individual rest of world country or region exceeding 10% of total net product revenues. Net product revenues within the United States exceeded 90% of total net product revenues for the three months ended March 31, 2022.

As of March 31, 2023 and December 31, 2022, the Company's accounts receivable were $223.8 million and $214.6 million, respectively, both of which were related to product sales receivable, net of discounts and allowances. As of March 31, 2023, the majority of the Company’s accounts receivable arose from product sales in the U.S. and all customers have standard payment terms that generally require payment within 60 to 91 days. Outside of the U.S., the majority of the Company’s customers have payment terms ranging between 60 and 150 days. Three individual customers accounted for 37%, 34% and 10% of accounts receivable from product sales as of March 31, 2023 and 36%, 35% and 12% of accounts receivable from product sales as of December 31, 2022. As of March 31, 2023, the Company believes that such customers are of high credit quality.

The following tables summarize an analysis of the change in reserves for discounts and allowances for each of the periods indicated:


	Chargebacks			Rebates			Prompt Pay			Other Accruals			Total
	(in thousands)
Balance, as of December 31, 2022	$	417		$	67,493		$	3,343		$	23,445		$	94,698
Provision		2,827			30,488			3,572			14,567			51,454
Adjustments relating to prior years		—			(2,162	)		—			—			(2,162	)
Payments/credits		(3,244	)		(28,025	)		(3,389	)		(14,040	)		(48,698	)
Balance, as of March 31, 2023	$	—		$	67,794		$	3,526		$	23,972		$	95,292


	Chargebacks			Rebates			Prompt Pay			Other Accruals			Total
	(in thousands)
Balance, as of December 31, 2021	$	799		$	60,506		$	2,798		$	6,363		$	70,466
Provision		2,437			24,989			2,950			9,181			39,557
Adjustments relating to prior years		—			(849	)		—			30			(819	)
Payments/credits		(2,906	)		(16,563	)		(2,645	)		(4,182	)		(26,296	)
Balance, as of March 31, 2022	$	330		$	68,083		$	3,103		$	11,392		$	82,908