Folgende Marktanteile hatten US-Fluggesellschaften 2018 bei Inlandsflügen.
- Southwest Airlines: 17.8%
- American Airlines: 17.8%
- Delta Air Lines: 16.9%
- United Airlines: 15%
- Alaska Airlines: 6.1%
- JetBlue Airways: 5.6%
- Spirit: 3.9%
- Frontier: 2.7%
- SkyWest: 2.7%
- Hawaiian: 1.6%
(Bureau of Transportation Statistics)