Basis of consolidation

The consolidated financial statements include the accounts of Inogen, Inc. and its wholly owned subsidiaries.  All intercompany balances and transactions have been eliminated.

Revenue

The Company generates revenue primarily from sales and rentals of its products. The Company’s products consist of its proprietary line of oxygen concentrators and related accessories. Other revenue, which is included in sales revenue on the consolidated statements of comprehensive income, consists of repair services and freight revenue for product shipments.

Sales revenue

Revenue is recognized upon transfer of control of promised products or services to customers in an amount that reflects the consideration the Company expects to receive in exchange for those products or services. Revenue from product sales is generally recognized upon shipment of the product but is deferred for certain transactions when control has not yet transferred to the customer.

The Company’s product is generally sold with a right of return and the Company may provide other incentives, which are accounted for as variable consideration when estimating the amount of revenue to recognize.  Returns and incentives are estimated at the time sales revenue is recognized. The provisions for estimated returns are made based on known claims and estimates of additional returns based on historical data and future expectations. Sales revenue incentives within the Company’s contracts are estimated based on the most likely amounts expected on the related sales transaction and recorded as a reduction to revenue at the time of sale in accordance with the terms of the contract. Accordingly, revenue is recognized net of allowances for estimated returns and incentives.

The Company also offers a lifetime warranty for direct-to-consumer sales of its portable concentrators. For a fixed price, the Company agrees to provide a fully functional portable oxygen concentrator for the remaining life of the patient. Lifetime warranties are only offered to patients upon the initial sale of portable oxygen concentrators by the Company and are non-transferable. Lifetime warranties are considered to be a distinct performance obligation that are accounted for separately from its sale of portable oxygen concentrators with a standard warranty of three years.

The revenue is allocated to the distinct lifetime warranty performance obligation based on a relative SSP method. The Company has vendor-specific objective evidence of the selling price for its equipment. To determine the selling price of the lifetime warranty, the Company uses its best estimate of the SSP for the distinct performance obligation as the lifetime warranty is neither separately priced nor is the selling price available through third-party evidence. To calculate the selling price associated with the lifetime warranties, management considered the profit margins of the overall business, the average estimated cost of lifetime warranties and the price of extended warranties. Revenue from the distinct lifetime warranty is deferred after the delivery of the equipment for three years and recognized on a straight-line basis during the fourth and fifth year, which is the estimated usage period of the contract based on the average patient life expectancy.

Revenue from the sale of the Company’s repair services is recognized when the performance obligations are satisfied, and collection of the receivables is probable. Other revenue from sale of replacement parts and non-warranty repair services is generally recognized when product is shipped to customers.

Freight revenue consists of fees associated with the deployment of products internationally and domestically when expedited freight options are requested or when minimum order quantities are not met. Freight revenue is generally recognized upon shipment of the product but is deferred if control has not yet transferred to the customer. Shipping and handling costs for sold products and rental assets shipped to the Company’s customers are included on the consolidated statements of comprehensive income as part of cost of sales revenue and cost of rental revenue, respectively.

The payment terms and conditions of customer contracts vary by customer type and the products and services offered.  For certain products or services and customer types, the Company requires payment before the products or services are delivered to the customer.  The timing of sales revenue recognition, billing and cash collection results in billed accounts receivable and deferred revenue in the consolidated balance sheet.

Contract liabilities primarily consist of deferred revenue related to lifetime warranties on direct-to-consumer sales revenue when cash payments are received in advance of services performed under the contract. The contract with the customer states the final terms of the sale, including the description, quantity, and price of each product or service purchase.  The increase in deferred revenue related to lifetime warranties for the nine months ended September 30, 2018 was primarily driven by $4,914 of payments received in advance of satisfying the distinct performance obligation, partially offset by $992 of revenues recognized that were included in the deferred revenue balance as of December 31, 2017.  Lifetime warranties on direct-to-consumer sales revenue of $14,742 and $10,820 as of September 30, 2018 and December 31, 2017, respectively, are classified within deferred revenue – current and noncurrent deferred revenue in the consolidated balance sheet.

The Company elected to apply the practical expedient in accordance with Accounting Standards Codification (ASC) 606—Revenue Recognition and did not evaluate contracts of one year or less for the existence of a significant financing component.  The Company does not expect any revenue to be recognized over a multi-year period with the exception of revenue related to lifetime warranties.

The Company’s sales revenue is primarily derived from the sale of its Inogen One systems, Inogen At Home systems, and related accessories to individual consumers, home medical equipment providers, distributors, the Company’s private label partner and resellers worldwide.  Sales revenue is classified into two areas: business-to-business sales and direct-to-consumer sales. The following table sets forth the Company’s sales revenue disaggregated by sales channel and geographic region:

Rental revenue

The Company recognizes equipment rental revenue over the non-cancelable lease term, which is one month, less estimated adjustments, in accordance with ASC 840 —Leases. The Company has separate contracts with each patient that are not subject to a master lease agreement with any third-party payor. The Company evaluates the individual lease contracts at lease inception and the start of each monthly renewal period to determine if there is reasonable assurance that the bargain renewal option associated with the potential capped free rental period would be exercised. Historically, the exercise of such bargain renewal option is not reasonably assured at lease inception and most subsequent monthly lease renewal periods. If the Company determines that the reasonable assurance threshold for an individual patient is met at lease inception or at a monthly lease renewal period, such determination would impact the bargain renewal period for an individual lease. The Company would first consider the lease classification issue (sales-type lease or operating lease) and then appropriately recognize or defer rental revenue over the lease term, which may include a portion of the capped rental period.

The lease term begins on the date products are shipped to patients and are recorded at amounts estimated to be received under reimbursement arrangements with third-party payors, including Medicare, private payors, and Medicaid. Due to the nature of the industry and the reimbursement environment in which the Company operates, certain estimates are required to record net revenue and accounts receivable at their net realizable values. Inherent in these estimates is the risk that they will have to be revised or updated as additional information becomes available. Specifically, the complexity of many third-party billing arrangements and the uncertainty of reimbursement amounts for certain services from certain payors may result in adjustments to amounts originally recorded. Such adjustments are typically identified and recorded at the point of cash application, claim denial or account review. The Company adjusts revenue for historical trends on revenue adjustments due to timely filings, deaths, hospice, and other types of analyzable adjustments on a monthly basis. Accounts receivable are reduced by an allowance for doubtful accounts which provides for those accounts from which payment is not expected to be received although product was delivered, and revenue was earned. The determination that an account is uncollectible, and the ultimate write-off of that account occurs once collection is considered to be not probable, and it is written-off and charged to the allowance at that time. Amounts billed but not earned due to the timing of the billing cycle are deferred and recognized in rental revenue on a straight-line basis over the monthly billing period. For example, if the first day of the billing period does not fall on the first of the month, then a portion of the monthly billing period will fall in the subsequent month and the related revenue and cost would be deferred based on the service days in the following month.

Rental revenue is recognized as upon transfer of control of promised products or services to customers in an amount that reflects the consideration the Company expects to receive in exchange for those products or services, less estimated adjustments. Revenue not billed at the end of the period is reviewed for the probability of collection and accrued if collection is probable. Rental revenue is not guaranteed, and payment will cease if the patient no longer needs oxygen or returns the equipment. Rental revenue is recognized at estimated allowable amounts that reflect the full consideration the Company expects to receive in exchange for the equipment; transfers to secondary insurances or patient responsibility have no net effect on revenue. Rental revenue is earned for that entire month if the patient is on service on the first day of the 30-day period commencing on the recurring date of service for a particular claim, regardless if there is a change in condition or death after that date.

Included in rental revenue are unbilled amounts for which the revenue recognition criteria had been met as of period-end but were not yet billed to the payor. The estimate of net unbilled rental revenue recognized is based on historical trends and estimates of future collectability. In addition, the Company estimates potential future adjustments and write-offs of these unbilled amounts and includes these estimates in the allowance for adjustments and write-offs of rental revenue which is netted against gross receivables.

Recently adopted accounting pronouncements

In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers, which supersedes nearly all existing revenue recognition guidance under U.S. GAAP. The core principle of ASU No. 2014-09 is to recognize revenues when promised goods or services are transferred to customers in an amount that reflects the consideration to which an entity expects to be entitled for those goods or services. ASU No. 2014-09 defines a five-step process to achieve this core principle and, in doing so, more judgment and estimates may be required within the revenue recognition process than are required under existing U.S. GAAP.  In March 2016, the FASB issued ASU No. 2016-08, Revenue with Contracts with Customers: Principal versus Agent Considerations (Reporting Revenue Gross versus Net), which is an amendment to ASU No. 2014-09 that improved the operability and understandability of implementation guidance of principal versus agent considerations by clarifying the determination of principal versus agent.  The Company completed its adoption plan including assessment of the Company’s revenue streams and analysis of all outstanding contracts by application of the five-step model to those contracts and revenue streams.  The Company adopted the standard on January 1, 2018, using the modified retrospective method. The Company finalized its analysis and the adoption of this standard did not have a material impact on the consolidated financial statements and internal controls over financial reporting.  

In January 2017, the FASB issued ASU No. 2017-01, Clarifying the Definition of a Business. The new guidance revises the definition of a business and provides new guidance in evaluating when a set of transferred assets and activities is a business. The Company adopted this standard on January 1, 2018. The adoption of this ASU did not have a material effect on the Company’s consolidated financial statement presentation or results.