	Year ended December 31,
	2019		2018
Geographic Market
United States	$	1,605,814	$	619,772
United Kingdom		665,627		300,091
Germany		102,427		53,784
Other		16,411		19,306
Total Net Sales	$	2,390,279	$	992,953

Revenue, net of distribution discounts, vouchers, rebates, returns, and co-payment assistance is solely generated from the sales of the gammaCore products. Revenue is recognized when delivery of the product is completed. The Company deems control to have transferred upon the completion of delivery because that is the point in which (1) it has a present right to payment for the product, (2) it has transferred the physical possession of the product, (3) the customer has legal title to the product, (4) the customer has risks and rewards of ownership and (5) the customer has accepted the product. After the products have been delivered and control has transferred, the Company has no remaining unsatisfied performance obligations.

Revenue is measured based on the consideration that the Company expects to receive in exchange for gammaCore, which represents the transaction price. The transaction price includes the fixed per-unit price of the product and variable consideration in the form of trade credits, vouchers, rebates, and co-payment assistance. The per-unit price is based on the Company’s established wholesale acquisition cost less a contractually agreed upon distributor discount with the customer. Any reserves based on estimated rebates with private payers was determined to be immaterial.

Trade credits are discounts that are contingent upon a timely remittance of payment and are estimated based on historical experience.

From February 2018 to mid-July 2018, the Company had a voucher program under which vouchers were issued to physicians to provide new patients with free therapy (i.e., one gammaCore device) by delivering non-voucher units for free therapy. The transaction price of the non-voucher units redeemed and estimated to be redeemed was recognized as contra-revenue. The cost to produce these units, in addition to any processing fees, are included as promotional expenses in selling, general, and administrative expense. After mid-July 2018, the Company modified its voucher program to provide its distributor with gammaCore and gammaCore Sapphire promotional units at no charge (“voucher units”). The voucher units have a distinct product item number to be used for the voucher program. The costs to produce these voucher units given to patients under the voucher program are recognized in promotional expense.

In October 2018, the Company launched its Partners for Coverage program that allows eligible commercial insurance patients uninterrupted access to gammaCore for up to two months while insurance coverage is being pursued. In February 2019, this program was modified to provide therapy to patients for up to 12 months while insurance coverage is being pursued. In December 2019, the Company terminated this program.

In addition, reimbursement for co-payments made by patients under the co-payment assistance program is considered variable consideration. Beginning in February 2019, eligible patients could receive a reduction of up to $300 from the cost of co-payments for the first month of therapy and a reduction of up to $250 from the cost of each refill for a maximum of 12 months. For the years ended December 31, 2019 and 2018, net sales reflect a reduction for the reduced cost of therapy under the co-payment assistance program. The calculation of the accrual is based on an estimate of claims and the cost per claim that the Company expects to incur associated with inventory that exists in the distribution channel at period end.

Effective March 1, 2020, the amount of monthly co-payment assistance has been reduced to a maximum of $100 per prescription.

Managed care rebates represent our estimated obligations to pharmacy benefit managers. Rebate accruals are recognized in the same period the related revenue is recognized. Gross to net accruals based on estimated rebates were determined to be de minimis.

The Company generally invoices the customer and recognizes revenue once its performance obligations are satisfied, at which point payment is unconditional. Accordingly, under ASC 606, the Company’s contracts with customers did not give rise to contract assets or liabilities during the year ended December 31, 2019 and 2018.

Agreed upon payment terms with customers are within 120 days of shipment. Accordingly, contracts with customers do not include a significant financing component.

The Company earns a significant amount of its revenue in the U.S. from the Veterans Administration and Department of Defense pursuant to its qualifying contract under the Federal Supply Schedule and open market sales to individual VA facilities and in the U.K. under the National Health Service.