Book fast! Frontier is having a promo code sale valid for purchase today only! Save 90% off the base fare for travel through May 23. Fares start at just $42 round-trip. There are well over 100 routes under $100 round-trip.

Use promo code SAVE90 when booking on to take 90% off the base fare for nonstop domestic flights. Travel is valid on Tuesdays and Wednesdays starting tomorrow, February 27, through May 23. Avoid blackout dates on March 27-28 & April 3-4.

The discount does not apply to taxes nor Frontier's online booking fee, which they label a "Carrier Interface Charge". This means some routes still won't have a very big price drop even with the big sticker shock of 90% off. However, there are plenty of routes where we are seeing very large discounts so you may be able to save big if you can travel in the middle of the week.

There is a long list of specific routes excluded from the promo code sale. Frontier operates about half of their markets on a limited and/or seasonal basis, so be sure to check out the fare details by clicking on the "See more details" link for the "Flexible Dates" fare on the following page. This page will inform you which months and days of the week Frontier travels any given route.

Tickets must be booked by 11:59 p.m. ET, tonight, February 26.

Nonstop fares include:

Denver to Las Vegas $42 round-trip

Atlanta to Orlando $50 round-trip

Cincinnati to Miami $56 round-trip

Columbus to Tampa $59 round-trip

Chicago to Fort Myers $65 round-trip

Austin to Las Vegas $69 round-trip

Detroit to Austin $70 round-trip

Minneapolis to Denver $71 round-trip

New York to Cincinnati $72 round-trip

Denver to Cleveland $74 round-trip

Atlanta to Salt Lake City $76 round-trip

Philadelphia to Denver $77 round-trip

Cleveland to Seattle $78 round-trip

Houston to Philadelphia $78 round-trip

Raleigh to Las Vegas $78 round-trip

Las Vegas to Orlando $80 round-trip

Cincinnati to Los Angeles $80 round-trip

Many more routes are available and these fares all work in reverse as well. Lowest fares may not be available throughout the entire travel period. Check our pages for all flights to DenverLas Vegas, MiamiOrlandoTampaFort Myers, Philadelphia, Cleveland, Austin, and San Jose to see more of today's finds. This is not a full list of Frontier cities, so check flights from your city to see what's available.

Keep in mind that Frontier charges extra for any bags larger than a small personal item (small backpack, briefcase, purse, etc.). Pack super light to get the lowest price. Checked bag fees start at $25 each way.

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