Frontier Airlines jetliners sit at gates along the A concourse at Denver International Airport. (David Zalubowski/ AP)

Frontier Airlines has added two new destinations to its roster of flights at Dulles International Airport.

Airline officials announced this month it will begin flying to Palm Beach and Cancun beginning in November.

In May, the airline, which is trying to rebrand itself as a low-cost carrier, announced new service from Dulles to 14 destinations — a boost for the airport, where the number of domestic flights has steadily decreased over the past few years. The number of domestic passengers traveling through Dulles dropped to 14.7 million between January 2013 and January 2014, a 6 percent decline. While some blamed weather for the drop, the number of passengers at Dulles has been shrinking for several years.

“We are excited to begin service from Washington-Dulles August 19 and quickly expand the number of routes we offer to 17,” said Daniel Shurz, Frontier’s senior vice president for commercial service, in a press release announcing the new routes.

According to a spokesperson, the airline will announce the 17th route (hint: “something sunny and international”) on Aug. 19.

Frontier’s service kicks off that day with nonstop services to Atlanta, Orlando and Minneapolis/St. Paul. Service to Charlotte begins Aug. 20; to Tampa on Aug. 21. Additional cities will come on line in September: Chicago-O’Hare; Cincinnati; Detroit; Fort Lauderdale, Fla.; Las Vegas; Memphis; Fort Myers, Fla.; St. Louis; and the St. Augustine/Jacksonville, Fla. area.

The airline recently changed its fare structure, so travelers may find themselves paying a la carte for services that used to be free. For example, the airline is now charging as much as $50 for placing bags in the overhead bin depending on which fare you purchase. See details here. Frontier, which is based in Denver, also offers service from Reagan National and Baltimore-Washington Thurgood Marshall International airports.