Frontier Airlines operates out of Terminal A at Orlando International Airport. This terminal is part of the main North Terminal Complex and serves both domestic and international flights. Once you enter Terminal A, Frontier's check-in area is on Level 3, the departures level. After check-in and security, you’ll board the Automated People Mover (APM) which transports you to Airside 1, where Frontier gates are located.
Ultimate Guide to Frontier Airlines MCO Terminal – Orlando International Airport