Frontier AirlinesFFT/ F9

Frontier Airlines is a major ultra-low-cost carrier headquartered in Denver, Colorado, founded in 1994 and operating as one of the largest airlines in the United States by passenger volume. The airline operates scheduled passenger flights primarily within the U.S. domestic market, with Denver International Airport serving as its primary hub and focus cities including Las Vegas, Orlando, and Phoenix. Frontier is known for its extremely low base fares and aggressive ancillary revenue model, charging separately for checked baggage, carry-ons, seat selection, and other services, which differentiates it from traditional full-service carriers. The airline is not part of any major global airline alliance but maintains various codeshare agreements with other carriers. Frontier's frequent flyer program, called Frontier Miles, allows members to earn and redeem rewards across flights and partner benefits. The carrier operates an all-economy configuration focused on cost efficiency and appeals primarily to price-conscious leisure travelers seeking affordable air travel options.