Update: Some offers mentioned below are no longer available. View the current offers here.In the past few weeks, we’ve written about Frontier Airlines offering $19 fares from Phoenix and $15 fares from Houston to San Francisco. Today they’re back at it with $15 fares from Chicago O’Hare, Miami and Philadelphia.More cheap fares on Frontier!Frontier is launching new service in American Airlines hub Miami and US Airways hub Philadelphia, and to celebrate they’re offering some super cheap fares on their new routes.Score a 14.99 fare from Chicago O’Hare to MiamiTickets must be purchased by 11:59 pm Eastern time on Sep. 30, 2014 for domestic, non-stop travel on Tuesdays and Wednesdays on certain dates from January 6-14, 2015. Fares are one way and do not require round-trip purchase. Aside from the $14.99 fares, Frontier is also offering $39 fares in select markets for December 30, 2014 through January 28, 2015While Frontier may not be a part of a major alliance and these cheap flights won’t help toward any major elite status, you can still bank extra credit card points by using a card that maximizes airfare purchases, like 3x points per dollar on airfare with the American Express® Gold Card or 2x points on the Chase Sapphire Preferred. Check out this post for more on maximizing airfare purchases.Report your success if you’re able to snag any of these deals!Sign up for our daily newsletterEmail addressSign upI would like to subscribe to The Points Guy newsletters and special email promotions. The Points Guy will not share or sell your email. See privacy policy.[card card-name=‘American Express® Gold Card’ card-id=‘22035076’ type=‘javascript’ bullet-id=‘1’]