The Company accounts for a contract when there is approval and commitment from both parties, the rights of the parties are identified, payment terms are identified, the contract has commercial substance, and collectability of consideration is probable. The Company’s contracts may contain one or more performance obligations. If a contract contains more than one performance obligation, the Company allocates the total transaction price to each of the performance obligations based upon the observable standalone selling price of the promised goods or services underlying each performance obligation. The Company recognizes revenue when control of the promised goods or services is transferred to the customer, which typically occurs at a point in time

upon shipment, delivery, or utilization, in an amount that reflects the consideration which the Company expects to be entitled in exchange for the promised goods or services. The amount the Company expects to be entitled to in exchange for the goods or services reflects any fixed amount stated per the contract and estimates for any variable consideration, such as discounts, to the extent that is it probable that a significant reversal of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is resolved.

The following sections discuss the Company’s revenue recognition policies by significant product category:

Bone Growth Therapies revenue is largely attributable to the U.S. and is comprised of third-party payor transactions and wholesale revenue.

The largest portion of Bone Growth Therapies revenue is derived from third-party payors. This includes commercial insurance carriers, health maintenance organizations, preferred provider organizations, and governmental payors, such as Medicare. Revenue is recognized when the product is fitted to and accepted by the patient and all applicable documents required by the third-party payor have been obtained. Amounts paid by third-party payors are generally based on fixed or allowable reimbursement rates. These revenues are recorded at the expected or preauthorized reimbursement rates, net of any contractual allowances or adjustments. Certain billings are subject to review by the third-party payors and may be subject to adjustment.

Wholesale revenue is related to the sale of the Company’s bone growth stimulators directly to durable medical equipment suppliers. Wholesale revenues are typically recognized upon shipment and receipt of a confirming purchase order, which is when the customer obtains control of the promised goods.

Biologics revenue is largely attributable to the U.S. and is primarily related to a collaborative arrangement with MTF, which extends through July 28, 2027. Under this arrangement, the Company markets tissue for bone repair and reconstruction under the brand names Trinity Evolution and Trinity ELITE. Per the terms of the agreement, MTF sources the tissue, processes it to create the bone growth matrix, packages, and delivers the tissue to the customer in accordance with orders received from the Company. The Company has exclusive global marketing rights for the Trinity Evolution and Trinity ELITE tissues, as well as non-exclusive marketing rights for other products, and receives marketing fees from MTF based on total sales. MTF is considered the primary obligor in these arrangements; therefore, the Company recognizes marketing service fees on a net basis within net sales upon shipment of the product to the customer.

Spinal Implants and Global Extremities products are distributed world-wide, with U.S. sales largely comprised of commercial sales and international sales derived from both commercial sales and through stocking distributor arrangements.

Commercial revenue is largely related to the sale of the Company’s Spinal Implants and Global Extremities products to hospital customers. The customer obtains control and revenues are recognized when these products have been utilized and a confirming purchase order has been received from the hospital.

Other revenues within the Spinal Implants and Global Extremities product categories are derived from stocking distributors, who purchase the Company’s products and then re-sell them directly to customers, such as hospitals. For revenue from stocking distributor arrangements, subsequent to the adoption of Topic 606 effective January 1, 2018, the Company recognizes revenue upon shipment and receipt of a confirming purchase order, which is when the distributor obtains control of the promised goods. The transaction price with stocking distributors is estimated based upon the Company’s historical collection experience with the stocking distributor. To derive this estimate, the Company analyzes twelve months of historical invoices by stocking distributor and the subsequent collections on those invoices for a period of up to 24 months subsequent to the invoice date. The historical collection percentage, which is specific to each stocking distributor, is then used to calculate the transaction price. Cost of sales is also recorded upon transfer of control of the product to the customer subsequent to the adoption of Topic 606.

Prior to the adoption of Topic 606, or for all periods presented prior to January 1, 2018, the Company recognized revenue from stocking distributor arrangements once the product was delivered to the end customer (the “sell-through method”). Because the Company did not have reliable information about when its distributors sold the product through to end customers, the Company used cash collection from distributors as a basis for revenue recognition under the sell-through method. Although in many cases the

Company was legally entitled to the accounts receivable at the time of shipment, the Company did not recognize accounts receivables or any corresponding deferred revenues at the time of shipment associated with stocking distributor transactions for which revenue was recognized on the sell-through method. The Company also considered whether to match the related cost of sales with revenue or to recognize cost of sales upon shipment. In making this assessment, the Company considered the financial viability of its stocking distributors, based on their creditworthiness, to determine if collectability of amounts sufficient to realize the costs of the products shipped was reasonably assured at the time of shipment. In instances where the stocking distributor was determined to be financially viable, the Company deferred the costs of sales until revenue was recognized.

The table below presents net sales, which includes product sales and marketing service fees, for each of the years ended December 31, 2019, 2018, and 2017.

	For the year ended December 31,
(U.S. Dollars, in thousands)	2019		2018		2017
Product sales	$	397,064	$	395,589	$	373,538
Marketing service fees		62,891		57,453		60,285
Net sales	$	459,955	$	453,042	$	433,823

Product sales primarily consists of the sale of Bone Growth Therapies, Spinal Implants, and Global Extremities products. Marketing service fees are received from MTF based on total sales of biologics tissues and relates solely to the Biologics product category within the Global Spine reporting segment. Marketing service fees received from MTF were $62.9 million, or approximately 96% of total Biologics revenues, for the year ended December 31, 2019. As MTF is the Company’s single supplier for the Trinity Evolution and Trinity ELITE tissue forms, which are derived from human cadaveric donors, any event or circumstance that would impact MTF’s continued access to donated human cadaveric tissue or the Company’s ability to market these tissues may adversely impact the Company’s financial results.

Revenues exclude any value added or other local taxes, intercompany sales and trade discounts. Shipping and handling costs for products shipped to customers are included in cost of sales, and were $2.8 million, $2.7 million and $3.0 million for the years ended December 31, 2019, 2018, and 2017, respectively.

Payment terms vary by the type and location of the Company’s customers and the products or services offered. The term between invoicing and when payment is due is not significant. Accounts receivable are analyzed on a quarterly basis to assess the adequacy of both reserves for doubtful accounts and contractual allowances. Revisions in allowances for doubtful accounts estimates are recorded as an adjustment to bad debt expense within sales and marketing expenses. Revisions to contractual allowances are recorded as an adjustment to net sales. The Company’s estimates are periodically tested against actual collection experience.

The Company will generally sell receivables from certain Italian hospitals each year to accelerate cash collections. During 2019, 2018, and 2017 the Company sold €9.8 million, €9.8 million, and €9.8 million ($10.9 million, $11.5 million, and $11.2 million) of receivables, respectively. The estimated related fees for 2019, 2018, and 2017 were $0.3 million, $0.3 million and $0.3 million, respectively, which is recorded as interest expense. Trade accounts receivables sold without recourse are removed from the balance sheet at the time of sale.

In June 2019, the Company received a payment of $1.4 million from the Administration of Medical Services of Puerto Rico, a government-owned corporation, in settlement of approximately $2.5 million of outstanding accounts receivable. This $2.5 million of outstanding accounts receivable had previously been fully reserved between the Company’s allowances for doubtful accounts and contractual allowances. As a result of this settlement, and in accordance with the Company’s policy, the Company recorded the resulting adjustment to contractual allowances of $0.4 million within net sales and the recovery of the allowance for doubtful accounts as a credit to bad debt expense of $1.0 million.

The Company’s contract assets, excluding trade accounts receivable (“other contract assets”), largely consist of payments made to certain distributors to obtain contracts, gain access to customers in certain territories, and to provide the benefit of the exclusive

distribution of the Company’s products. Other contract assets are included in other long-term assets and were $3.7 million and $1.9 million as of December 31, 2019 and 2018, respectively.

Other contract assets are amortized on a straight-line basis over the term of the related contract. No impairments were incurred for other contract assets in 2019 or 2018. Further, the Company has applied the practical expedient allowed within Topic 606 to expense sales commissions when incurred, as the applicable amortization period would be for one year or less.