REVENUE	6 Months Ended
Jun. 30, 2017
Risks and Uncertainties [Abstract]
REVENUE	Revenue Revenue Recognition and Net Product Sales Total revenues are comprised of product sales of Carticel, Epicel, MACI and surgical kits. Revenue is recognized when persuasive evidence of an arrangement exists, the goods are shipped or delivered, depending on shipping terms, title and risk of loss pass to the customer and collectability is reasonably assured. Shipping and handling costs are included as a component of revenue. The Company recognizes product revenues from sales of Epicel, Carticel and MACI upon delivery to patients as long as (i) there is persuasive evidence that an arrangement exists between ourselves and the customer, (ii) collectability is reasonably assured and (iii) the price is fixed or determinable. For Carticel and MACI, prior authorization or confirmation of coverage level by the patient’s private insurance plan, hospital or government payer is a prerequisite to the shipment of product to a patient. The Company's net product revenues are calculated by estimating expected payments for insurance, hospital or patient payments at the time it recognizes the gross revenue. The estimates are updated prospectively as new information becomes available. The Company sells Epicel directly to hospitals and retains the credit and collection risk from the end customer. From July 1, 2016 through June 30, 2017, the Company utilized a direct sales model for Carticel and MACI whereby the Company retained the credit and collection risk from the end customer. During that period, the Company utilized Dohmen Life Science Services, LLC (DLSS) to provide patient support services and reimbursement services, but this provider did not purchase and take title to Carticel or MACI. On May 15, 2017, both parties mutually terminated the agreement effective June 30, 2017. The Company utilizes Vital Care, Inc. (Vital Care) to provide data reporting services and to purchase, bill and collect from certain payers for Carticel and MACI. In April 2017, the Company was notified of a contractual dispute between Vital Care and a third-party payer and as a result, during the three months ended March 31, 2017, the Company increased its estimated revenue allowances, reducing revenue by $2.1 million related to 2016 sales and $0.7 million related to 2017 sales to reflect the lower reimbursement that would be obtained if the claims are ultimately required to be treated as out-of-network. Subsequently, the dispute was resolved and the negotiated reimbursement resulted in the Company's ability to reduce its estimated sales allowances by $1.4 million, which resulted in additional revenue in the second quarter related to sales which originated primarily in 2016. As a result of the continuing evaluation and assessment of these expected payments, our estimates for expected payments could change. On May 15, 2017, the Company entered into a distribution agreement with Orsini Pharmaceutical Services, Inc. (Orsini) to appoint Orsini as a specialty pharmacy distributor of Carticel and MACI to patients' physicians and other healthcare providers. Orsini will work with the Company's third party service provider for the management of patient cases related to Carticel and MACI. The initial term of the distribution agreement will end on May 15, 2019 with the option of two additional two-year terms. Orsini takes title to Carticel and MACI upon shipment of the product and assumes credit and collection risk. The Company ships the product to the surgical suite. Concentration of Credit Risk Revenue from one customer, the Carticel and MACI distributor in the U.S., represented approximately 14% of total revenue during the three months ended June 30, 2017. Accounts receivable from the same customer accounted for 17% of the outstanding accounts receivable as of June 30, 2017. For the three and six months ended June 30, 2016, the Company's largest customer represented 69% and 65% of total revenue, respectively. The next largest customer represented approximately 11% and 14% of revenue for the three and six ended June 30, 2017, respectively, and 13% and 15% of total revenue during the three and six months ended June 30, 2016, respectively. No other customer accounted for more than 10% of revenue or accounts receivable in 2017 or as of December 31, 2016.

Revenue

Revenue Recognition and Net Product Sales

Total revenues are comprised of product sales of Carticel, Epicel, MACI and surgical kits. Revenue is recognized when persuasive evidence of an arrangement exists, the goods are shipped or delivered, depending on shipping terms, title and risk of loss pass to the customer and collectability is reasonably assured. Shipping and handling costs are included as a component of revenue.

The Company recognizes product revenues from sales of Epicel, Carticel and MACI upon delivery to patients as long as (i) there is persuasive evidence that an arrangement exists between ourselves and the customer, (ii) collectability is reasonably assured and (iii) the price is fixed or determinable. For Carticel and MACI, prior authorization or confirmation of coverage level by the patient’s private insurance plan, hospital or government payer is a prerequisite to the shipment of product to a patient. The Company's net product revenues are calculated by estimating expected payments for insurance, hospital or patient payments at the time it recognizes the gross revenue. The estimates are updated prospectively as new information becomes available.

The Company sells Epicel directly to hospitals and retains the credit and collection risk from the end customer. From July 1, 2016 through June 30, 2017, the Company utilized a direct sales model for Carticel and MACI whereby the Company retained the credit and collection risk from the end customer. During that period, the Company utilized Dohmen Life Science Services, LLC (DLSS) to provide patient support services and reimbursement services, but this provider did not purchase and take title to Carticel or MACI. On May 15, 2017, both parties mutually terminated the agreement effective June 30, 2017.

The Company utilizes Vital Care, Inc. (Vital Care) to provide data reporting services and to purchase, bill and collect from certain payers for Carticel and MACI. In April 2017, the Company was notified of a contractual dispute between Vital Care and a third-party payer and as a result, during the three months ended March 31, 2017, the Company increased its estimated revenue allowances, reducing revenue by $2.1 million related to 2016 sales and $0.7 million related to 2017 sales to reflect the lower reimbursement that would be obtained if the claims are ultimately required to be treated as out-of-network. Subsequently, the dispute was resolved and the negotiated reimbursement resulted in the Company's ability to reduce its estimated sales allowances by $1.4 million, which resulted in additional revenue in the second quarter related to sales which originated primarily in 2016. As a result of the continuing evaluation and assessment of these expected payments, our estimates for expected payments could change.

On May 15, 2017, the Company entered into a distribution agreement with Orsini Pharmaceutical Services, Inc. (Orsini) to appoint Orsini as a specialty pharmacy distributor of Carticel and MACI to patients' physicians and other healthcare providers. Orsini will work with the Company's third party service provider for the management of patient cases related to Carticel and MACI. The initial term of the distribution agreement will end on May 15, 2019 with the option of two additional two-year terms. Orsini takes title to Carticel and MACI upon shipment of the product and assumes credit and collection risk. The Company ships the product to the surgical suite.

Concentration of Credit Risk

Revenue from one customer, the Carticel and MACI distributor in the U.S., represented approximately 14% of total revenue during the three months ended June 30, 2017. Accounts receivable from the same customer accounted for 17% of the outstanding accounts receivable as of June 30, 2017. For the three and six months ended June 30, 2016, the Company's largest customer represented 69% and 65% of total revenue, respectively. The next largest customer represented approximately 11% and 14% of revenue for the three and six ended June 30, 2017, respectively, and 13% and 15% of total revenue during the three and six months ended June 30, 2016, respectively. No other customer accounted for more than 10% of revenue or accounts receivable in 2017 or as of December 31, 2016.