Inogen Inc is a medical technology company that develops and manufactures portable oxygen concentrators used to deliver oxygen therapy to patients with chronic respiratory conditions. Its key product, the Inogen One system, is a lightweight alternative to traditional, stationary oxygen concentrator systems and oxygen tanks. The firm sells its products to home medical equipment providers and also rents products directly to patients. The majority of rental revenue comes from Medicare service reimbursement programs. Internationally, Inogen sells its products through distributors or large gas companies and home oxygen providers. Inogen generates the majority of its revenue in the United States.