With Frontier Airlines the fee for a standard carry-on bag (i.e., something that goes in the overhead bin, not just under-seat) varies depending on when you buy it and your route.
Here’s a rough guideline:
If you add the carry-on at the time of booking: about US $29 - $69.
If you wait until at check-in or at the gate: it could rise to US $79-$115 or more.
Always check the “Bag Price Checker” on Frontier’s website for your exact flight to get the current fee.
