In late 2018, BWI Thurgood Marshall Airport announced that Frontier Airlines plans to start nonstop service to Denver on March 14. Frontier will initially offer four weekly roundtrip flights between BWI Marshall Airport and Denver International Airport. The airline will operate the flights using its Airbus A320 aircraft.

Frontier is the second new airline in 2018 to announce entry into the BWI Marshall Airport market. Icelandair announced in January 2018 that it would begin nonstop service between BWI Marshall and Reykjavik, Iceland. The Icelandair service began in May 2018.