Frontier Airlines DEN Terminal provides allocated seating, which includes regular and extra-legroom stretch seats. Priority passengers and those in need of help board first in a zone-based approach. Groups are used for general boarding. Since boarding shuts fifteen minutes prior to departure, passengers should arrive at the gate early.

 

For More : https://www.terminalfind.com/frontier-airlines/frontier-airlines-den-terminal-denver-international-airport/