Revenue Recognition We recognize revenue primarily from the sale of PROVENGE. Revenue from the sale of PROVENGE is recorded net of product returns and estimated price discounts, including rebates and chargebacks offered pursuant to mandatory federal and state government programs and to members of Group Purchasing Organizations ( GPOs ) with which we have contracts. Revenue from sales of PROVENGE is recognized upon confirmed product delivery to and issuance of a product release form to the physician. Product returns are limited to those instances in which the physician receives the product but does not infuse the product prior to expiry, either due to timing or the failure of the product to meet specifications and pass site inspection. Due to the limited usable life of PROVENGE of approximately 18 hours from the completion of the manufacturing process to patient infusion, actual return information is known and credited against sales in the month incurred. PROVENGE sales are direct to physician; however, we have entered into distribution agreements with several credit-worthy third-party wholesalers (the  Wholesalers ) whereby we manufacture and ship the product direct to the physician and transfer the sale of PROVENGE to the Wholesalers. Under the distribution agreements, the Wholesalers assume all bad debt risk from the physician or institution; therefore no allowance for bad debt is recorded. Under the terms of the distribution agreements, our return policy allows for the return of product that has expired or has a defect prior to delivery, product that is damaged during delivery and product that cannot be infused because it does not otherwise meet specified requirements. Our product is subject to certain required pricing discounts via rebates and/or chargebacks pursuant to mandatory federal and state government programs and, accordingly, revenue recognition requires estimates of rebates and chargebacks. We have agreements with the Centers for Medicare and Medicaid Services ( CMS ) providing for a rebate on sales