Inogen is a medical device company focused on home respiratory care, primarily selling portable oxygen concentrators (POCs) to patients with chronic respiratory conditions like COPD. Inogen's POCs — the Inogen One and Inogen Rove product lines — pull oxygen from surrounding air and deliver it on demand, eliminating the need for bulky oxygen tanks and delivery schedules. Inogen sells through three U.S. channels: B2B sales to home medical equipment providers and distributors (~45% of U.S. revenue), direct-to-consumer outright sales (~30%), and direct-to-consumer rentals billed to Medicare or private insurance (~25%). Internationally (~40% of total revenue), Inogen sells through distributors across ~70 countries, with Europe as the primary market. Beyond POCs, Inogen is expanding into stationary oxygen concentrators (Inogen Voxi 5, sourced via a Yuwell collaboration), airway clearance devices (Simeox, targeting bronchiectasis patients via a razor/razor-blade model with recurring disposables revenue), and CPAP masks (Aurora, targeting sleep apnea patients). These new products expand Inogen's addressable market from ~$400M to over $3B by management's estimate. Inogen's profitability is driven by POC unit volumes, channel mix (DTC and rental carry higher margins than B2B), and operating leverage. The company returned to positive adjusted EBITDA in FY25. Inogen holds ~$121M in cash with no debt, and a 9.9% equity stake from Yuwell anchors its product collaboration.