Spirit Airlines is advertising a massive 90% off base fares promotion with the code 90PCT! Sounds incredible, right? Before you start planning your dream getaway, there are a few things you should know. The deal is valid for travel between January 21st and March 4th, 2026, but only on Tuesdays, Wednesdays, and Saturdays. Plus, there are blackout dates to watch out for, including February 14th, 17th, and 21st, 2026. You'll need to book by 11:59 PM EST on January 14, 2026. Now, here's the catch that makes this deal less amazing than it appears: Spirit tacks on a hefty "Passenger Usage Charge" of $27.99 that isn't discounted. So, while you might see a huge percentage shaved off the initial fare, the final price might not be as drastically reduced as you'd hoped. Why does this matter to you? Well, if you're flexible with your travel dates and destinations, you might still snag a genuinely good deal, especially on longer routes where the base fare is higher. However, don't expect to fly for next to nothing. Remember to factor in those extra charges and compare the final price with other airlines before booking. Always do your homework before jumping on what seems like an incredible deal!