Revenue Recognition — Revenues from sales of products are recognized when title and risk of loss passes to the customer, typically upon delivery. Recognition of revenue also requires reasonable assurance of collection of sales proceeds and completion of all performance obligations. Domestically, sales discounts are issued to customers at the point-of-sale, through an intermediary wholesaler (known as chargebacks), or in the form of rebates. Additionally, sales are generally made with a limited right of return under certain conditions. Revenues are recorded net of provisions for sales discounts and returns, which are established at the time of sale. In addition, revenues are recorded net of time value of money discounts if collection of accounts receivable is expected to be in excess of one year. Accruals for chargebacks are reflected as a direct reduction to accounts receivable and accruals for rebates are recorded as current liabilities. The accrued balances relative to the provisions for chargebacks and rebates included in Accounts receivable and Accrued and other current liabilities were $198 million and $2.4 billion, respectively, at December 31, 2017 and $196 million and $2.7 billion, respectively, at December 31, 2016.
The Company recognizes revenue from the sales of vaccines to the Federal government for placement into vaccine stockpiles in accordance with Securities and Exchange Commission (SEC) Interpretation, Commission Guidance Regarding Accounting for Sales of Vaccines and BioTerror Countermeasures to the Federal Government for Placement into the Pediatric Vaccine Stockpile or the Strategic National Stockpile. This interpretation allows companies to recognize revenue for sales of vaccines into U.S. government stockpiles even though these sales might not meet the criteria for revenue recognition under other accounting guidance.

About Revenue Disclosures

Revenue disclosures under ASC 606 explain how a company identifies performance obligations, allocates transaction prices, and determines when revenue is recognized. This section is essential for understanding whether reported revenue reflects genuine economic activity or aggressive accounting choices. Analysts examine the mix of point-in-time versus over-time recognition, which directly affects revenue timing and comparability.

Key signals: rising contract liabilities (deferred revenue) suggest strong future revenue visibility, while declining contract assets may indicate slowing project milestones. Watch for variable consideration estimates — rebates, returns, and performance bonuses that require management judgment. Significant changes in disaggregated revenue by geography or product line can reveal shifting business mix before it appears in headline numbers. Compare revenue growth against contract liability growth to assess sustainability, and scrutinize any changes in the timing of recognition that coincide with earnings pressure.