Revenue Recognition All of the Companys revenue is derived from long-term contracts that span multiple years. The Company accounts for revenue in accordance with ASC Topic 606, Revenue from Contracts with Customers (ASC 606). Adoption of ASC 606 . On January 1, 2018, the Company adopted ASC 606 using the modified retrospective method applied to those contracts that were not completed as of January 1, 2018. Results for reporting periods beginning after January 1, 2018 are presented under ASC 606, while prior period amounts are not adjusted and continue to be reported in accordance with our historical accounting under ASC 605, Revenue Recognition . The cumulative impact of adopting ASC 606 as of January 1, 2018 was a decrease to deferred revenue of approximately $1.8 million ; a decrease to deferred costs of approximately $2.1 million ; an increase to receivables of approximately $0.1 million and a net increase to opening accumulated deficit of $0.2 million , net of tax. For the year ended December 31, 2018, the impact to revenues as a result of applying ASC 606 was an increase of approximately $ 1.0 million . Performance Obligations . A performance obligation is a promise in a contract to transfer a distinct good or service to the customer, and is the unit of account in ASC 606. A contracts transaction price is allocated to each distinct performance obligation and recognized as revenue when, or as, the performance obligation is satisfied. As of December 31, 2018, the Company's active performance obligations, for the contracts outlined in Note 3 , consist of the following: three performance obligations relate to research and development services; two relate to manufacture and delivery of product; and one is associated with storage of product. Contract modifications may occur during the course of performance of our contracts. Contracts are often modified to account for changes in contract specifications or requirements. In most instances, contract modifications are for services that are not distinct, and, therefore, are accounted for as part of the existing contract. The Companys performance obligations are satisfied over time as work progresses or at a point in time. Substantially all of the Companys revenue related to research and development performance obligations is recognized over time, because control transfers continuously to our customers. Typically, revenue is recognized over time using costs incurred to date relative to total estimated costs at completion to measure progress toward satisfying the Companys performance obligations. Incurred cost represents work performed, which corresponds with, and thereby best depicts, the transfer of control to the customer. Contract costs include labor, material, overhead, and third-party services. Revenue connected with the performance obligation to deliver courses of oral TPOXX to the Strategic Stockpile, which includes related services, milestones and advance payments under the 2011 BARDA Contract, has been recognized at a point in time. Revenue associated with this performance obligation was recognized when BARDA obtained control of the asset, which was upon delivery to and acceptance by the customer and at the point in time when the constraint on the consideration was resolved. The consideration, which is variable consideration, was constrained until the FDA approved oral TPOXX for the treatment of smallpox on July 13, 2018. Prior to FDA approval, consideration had been constrained because the FDA Approval Replacement Obligation (as defined in Note 3) had not been quantified or specified. Following FDA approval, the possibility of having to replace product pursuant to the FDA Approval Replacement Obligation was essentially eliminated and deemed to be remote since there was no difference between the approved product and the courses of oral TPOXX that had been delivered to the Strategic Stockpile. Contract Estimates . Accounting for long-term contracts and grants involves the use of various techniques to estimate total contract revenue and costs. Contract estimates are based on various assumptions to project the outcome of future events that often span multiple years. These assumptions include labor productivity; the complexity of the work to be performed; external factors such as customer behavior and potential regulatory outcomes; and the performance of subcontractors, among other variables. The nature of the work required to be performed on many of the Companys performance obligations and the estimation of total revenue and cost at completion are complex, subject to many variables and require significant judgment. The consideration associated with research and development services is variable as the total amount of services to be performed has not been finalized. The Company estimates variable consideration as the most likely amount to which it expects to be entitled. The Company includes estimated amounts in the transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur and when any uncertainty associated with variable consideration is resolved. The Companys estimates of variable consideration and determination of whether to include estimated amounts in the transaction price are based largely on an assessment of our historical and anticipated performance, external factors, trends and all other information (historical, current and forecasted) that is reasonably available to us. A significant change in one or more of these estimates could affect the profitability of the Companys contracts. As such, the Company reviews and updates its contract-related estimates regularly. The Company recognizes adjustments in estimated revenues, research and development expenses and cost of sales and supportive services under the cumulative catch-up method. Under this method, the impact of the adjustment on revenues, research and development expenses and cost of sales and supportive services recorded to date on a contract is recognized in the period the adjustment is identified. Contract Balances . The timing of revenue recognition, billings and cash collections may result in billed accounts receivable, unbilled receivables (contract assets) and customer advances and deposits (contract liabilities) in the consolidated balance sheets. Generally, amounts are billed as work progresses in accordance with agreed-upon contractual terms either at periodic intervals (monthly) or upon achievement of contractual milestones. Under typical payment terms of fixed price arrangements, the customer pays the Company either performance-based payments or progress payments. For the Companys cost-type arrangements, the customer generally pays the Company for its actual costs incurred, as well as its allocated overhead and G&amp;A costs. Such payments occur within a short period of time. Remaining Performance Obligations . Remaining performance obligations represent the transaction price for which work has not been performed and excludes unexercised contract options. As of December 31, 2018 the aggregate amount of transaction price allocated to remaining performance obligations for the 2011 BARDA Contract, 2018 BARDA Contract and the IV Formulation R&amp;D Contract was $58.1 million . The Company expects to recognize this amount as revenue over the next five years as the specific timing for satisfying the performance obligations is subjective and outside the Companys control. Deferred Revenue When the Company receives