The ultra-low-cost airline game changed forever in 2026: Spirit – the airline that taught America to distrust the overhead bin – shut down on May 2, and the survivors repriced everything around it. The result is a fee landscape where the advertised $39 fare and the ticket you actually pay can differ by more than $150, and where the difference between booking a bag online and paying at the gate is real money.
Here is what the big three budget carriers charge in 2026, and the math that decides when a budget airline is not actually cheaper.
The Fee Table: Frontier, Allegiant, and the Ghost of Spirit
| Carrier | Carry-on fee | First checked bag | The catch |
|---|---|---|---|
| Frontier | Dynamic – roughly $69 at booking to $99 at the gate | $69-99 | 35-lb weight limit on carry-ons; prices vary by route and date |
| Allegiant | $10-75 per segment | $15-70 ($75 at airport) | Charged per segment – a round trip pays twice; smallest personal-item allowance |
| Spirit (ended May 2, 2026) | Was $65 at booking, $99 at gate | Was $55-99 | Chapter 7 liquidation – historical benchmark only |
| Southwest | Still free | $45 first / $55 second (new fees) | Checked bags are no longer free – the old giveaway is gone |
| JetBlue Blue Basic | Free | $45 and up | Only recent Blue Basic fares include the overhead bin |
| Avelo | $34 and up | $43 and up | Dynamic, rises at the airport |
The Three Rules That Decide the Real Price
- Timing is the multiplier. Every carrier prices bags cheapest at booking and most expensive at the gate – typically a $30-55 swing per bag per direction. Spirit’s gate markup was 52% over its booking price, and Frontier’s PIRG-priced example ran $69 at booking to $99 at the gate for the same bag.
- Allegiant charges per segment. The published $10-75 range is one-way math: a round trip with a carry-on costs the fee twice, up to $150. No other major US budget carrier structures it this way.
- Frontier weighs carry-ons. A 35-pound (16 kg) weight limit – unusual for a US airline – means a fully packed roller can be flagged even when it fits the sizer. The size limit is 24x16x10 inches.
The Legacy-Carrier Fine Print Got Worse Too
The 2026 shuffle reached the big airlines as well: most major carriers raised first-checked-bag fees by about $10 in early 2026, putting a standard first bag around $45-50 on domestic tickets. United remains the only legacy carrier that excludes carry-ons from domestic Basic Economy – and it charges a $25 gate handling fee if you show up with one anyway, on top of the checked bag you then have to buy. Third checked bags and overweight bags (70-100 lbs) both run about $200 at American, Delta, United and JetBlue – the number behind the viral “$200 bag fee” rumor.
When the Budget Airline Loses the Math
Add a round-trip carry-on to a budget base fare and the gap closes fast: Frontier’s example trip cost $138 combined for one carry-on plus one checked bag. On many routes, a Delta, United or American Basic Economy ticket – which includes a free overhead carry-on on most domestic routes – prices at or below the budget total once bags are counted. The playbook:
- Price the total, never the fare. Add your exact bags before comparing; use search tools that show total price with a carry-on included.
- Buy bags at booking. Online, at the moment of purchase, is the cheapest moment in every carrier’s fee curve.
- Check the bundle. Frontier’s WORKS bundle includes carry-on, checked bag, seat selection and refundability – on many routes it costs less than the same items bought separately.
- Measure the personal item. The free bag is 18x14x8 inches on Frontier and Allegiant (Allegiant’s runs a slimmer 16x15x7) – a regular school backpack is right at the edge, and gate agents measure with a metal sizer.
The Bottom Line
Budget airlines are still cheap for one specific traveler: the person flying with a personal item only, on a nonstop, with bags decided at booking. Everyone else should run the bag math before celebrating the $39 fare – and in 2026, that math got stricter, not looser.
Flying to Europe instead? Our guide to European budget airline hidden costs covers Ryanair and easyJet fee traps. And if a bag does vanish, the lost luggage first-hour guide tells you exactly what to do. More fare-side analysis sits in our flight booking tips section.