Frontier Airlines' Kids Fly Free: The definitive guide

When traveling with kids, one of the biggest expenses of the vacation can be the airfare for the whole family. Of course you can use points and miles to offset your cost, but what if I told you that one airline actually lets your kids fly free ... at least on certain dates?

In early 2019, Frontier Airlines introduced a "Kids Fly Free" offer. With this promotion, children ages 14 and under can fly for free with a paid adult ticket on eligible Frontier flights. Of course, there are stipulations to contend with, but when Frontier says free, they mean it — no extra taxes or fees tacked on for the ticket itself. This offer, along with other family-friendly initiatives from Frontier put it above the other budget carriers in the U.S. for the TPG 2019 best airlines for families rankings.

Related: The Best Credit Cards for Family Travel

You need a Discount Den membership

Although this is an incredible deal, you must have a Discount Den membership, which costs $59.99 per year and is the only way you'll have access to the Kids Fly Free promotion. There are other benefits to this membership, such as lower fares and the ability to book flights earlier than the general public when new flight schedules are released, so the math for it works in your favor if you fly Frontier even just twice a year.

The good thing about this membership is that only one parent typically needs to purchase it since the benefits extend to six people on the reservation. This means the Discount Den subscriber and up to five other people receive access to the lower fares and other perks. When using the Kids Fly Free offer, for every adult (15 years and older), one child can fly for free. And you can take advantage of this offer multiple times on a single reservation. For example, one parent can pay for the Discount Den membership and if you book an eligible flight for two adults and two kids on the reservation, both kids can fly for free.

Note: Your Discount Den membership expires one year after it's purchased, however, you can use the benefits for flights booked after your membership expires as long as you have the membership at the time of booking. This means if your membership is expiring, your kids can still fly for free for a few months after it expires as long as you book the flights in advance.

Eligible 'Kids Fly Free' flights and dates

Unlike the Southwest Companion Pass, which lets you buy one/get one 365 days a year on any scheduled flight, dates and routes are more limited with Frontier. For most of the year, flights on Tuesdays and Wednesdays, as well as some Thursdays and Saturdays, are eligible for the Kids Fly Free promotion. The date requirement changes every so often depending on the time of the year, and holiday time periods are typically blacked out. For example, do not expect your child to fly free during the entire December break, Thanksgiving week or virtually any long weekend.

While Frontier operates some routes to the Caribbean, as well as many routes to cities in Mexico, only U.S. domestic flights are included. Additionally, Frontier has a few dozen other excluded routes, which can change throughout the year depending on the season.

You must book at least 14 days in advance to take advantage of the promotion and only round-trip flights are eligible Kids Fly Free.

The Frontier Kids Fly Free page lists all of the eligible days of the week and blackout dates (up until the schedule release date) as well as excluded routes.

Combine the promotion with fare sales

Despite the many restrictions that come along with Kids Fly Free, you can often get a great deal when combining it with one of Frontier's regular fare sales. Frontier frequently offers flight deals, whether it is penny fares or 50% off flights, you can stack the deals as long as those fare sales do not require you to enter a promotion code.

Booking your child’s free Frontier flight

To book your child’s free Frontier flight with a Discount Den membership, log in to your Frontier account and search for your desired route. Include the number of adults and children who will be on the reservation. Your flight options will appear and you’ll see the “Kids Fly Free” icon below the flight price on eligible dates. (Note: If you do not have a Discount Den membership, continue with your flight selection and a pop-up window will appear giving you the option to purchase the membership.)

Note: You must book your child's flight at the time of making the initial reservation, you cannot add your child on at a later date.

You’ll then be prompted to customize your fare (including any bundle options) and select your seats, which costs extra per person -- no freebies for the kids. Your reservation’s final pricing will display after you’ve selected any add-ons.

In the sample reservation above, the final price for four passengers (two adults and two children) is just $183.92 round-trip. That is an absolute steal for a whole family to fly from Providence to Orlando during the winter months. Even if you factor in the annual cost of the $59.99 Discount Den membership, you are looking at $243.91 total, or $60.98 per passenger. Since your Discount Den membership is good for an entire year, you can continue to have your Kids Fly Free on many additional Frontier flights for the next twelve months.

Bottom line

Frontier's Kids Fly Free can be a great money-saving offer for families, but remember to consider all the extra charges when comparing prices to another airline. Because Frontier is a low-cost carrier, you'll pay for carry-on bags that don't fit under your seat and seat for advance seat assignments if you need those. Even though you are not paying for your child’s plane ticket, you will still have to pay these add-on fees for each passenger in your party if you choose to add them.

Here are some additional tips to help you weigh the pros and cons of flying budget carriers:

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