You’ve heard of all-you-can-eat buffets — how about all-you-can-fly airlines?

Frontier Airlines just announced something called the Go Wild! Summer Pass, which allows travelers unlimited flights between May 2 to September 30 for an introductory price of $399.

The airline first introduced the program last November but has since lowered the rate for the summer months.

Introducing the new all-you-can-fly GoWild! Summer Pass!

The pass offers exclusive access to unlimited flights between our U.S. & international destinations from 5/2 – 9/30/23.

A limited # of passes are available for $399.* https://t.co/YyEamzlIDq. pic.twitter.com/Nzfrkr4rSE

— Frontier Airlines (@FlyFrontier) February 1, 2023

Sounds too good to be true? It depends.

The plan is excellent for budget travelers as long as they’re super-flexible about their travel dates.

“For people with flexible schedules, this is a terrific opportunity to have a truly epic summer and then some, soaking up rays on the beach, exploring national parks, and visiting new cities,” said Daniel Shurz, senior vice president of commercial for Frontier.

Related:

How the Summer Pass works

The all-you-can-fly rate of $399 comes with some caveats.

Customers can only book flights the day before departure for domestic flights and ten days before for international flights. The same goes for return flights.

Frontier boasts that the cost of these flights is 1 cent, but that doesn’t include add-on fees like bags, seats, and other products such as drinks and snacks. The flights are also subject to blackout periods.

The $399 passes are being sold on a “first come, first served” basis, according to the airline.

What is Frontier Airlines?

In case you’re not familiar with Frontier — it’s a low-cost carrier serving over 120 destinations across the US, Mexico, and the Caribbean, including eight new routes to Puerto Rico.

The Denver-based airline is famous for its ultra-low fares but also for some cost-cutting measures, such as the recent announcement that it would no longer offer human-to-human customer support.

Last year, Frontier failed in its attempt to merge with fellow budget-airline Spirit, which merged with JetBlue.

Frontier’s seating configuration and lighter weight have contributed to the airline’s average of 43% fuel savings compared to other U.S. airlines, making it the most fuel-efficient airline, according to Frontier’s website.