This is a list of airlines which have an air operator's certificate issued by the Federal Aviation Administration of the United States. Note: Destinations in bold indicate primary hubs, those in italic indicate secondary hubs, and those with regular font indicate focus cities. For legacy carriers American, Delta, and United, the most strategic/well connected hubs are shown as Primary Hubs. Passenger airlines Mainline Regional Commuter Charter Cargo airlines Air ambulances State-run airlines See also Lists of airlines List of airlines of Puerto Rico List of airports in the United States List of largest airlines in North America List of defunct airlines of the United States Major airlines of the United States Proposed airlines of the United States References United States United States aviation-related lists