Spirit Airlines DEN Terminal Spirit Airlines DEN Terminal provides a variety of services for low-cost passengers and is based out of Concourse A at Denver International Airport (DEN). Low-cost solutions are prioritized in luggage policies, and passengers have the option of checking in online or at self-service kiosks. If it fits beneath the seat, carry-on luggage is free; checked baggage costs money. The travel experience is improved by the airport's assortment of dining and shopping opportunities. Spirit provides a basic onboard service with the option to buy snacks and drinks. At DEN, Spirit Airlines strives to offer a convenient and reasonably priced travel experience with effective boarding and customer care.