To avoid paying for bags on Frontier Airlines, your primary strategy should be to travel with only one Personal Item that fits within the strict dimensions of 18" x 14" x 8". Unlike many other carriers, Frontier charges for both carry-on and checked bags, but one personal item (like a small backpack or laptop bag) is included for free. Another effective method is to hold the Frontier Airlines World Mastercard, which offers a "Free Checked Bag" benefit for the primary cardholder on all Frontier-operated flights. Additionally, frequent flyers can attain Elite Diamond or Elite Black status through the Frontier Miles program, which includes free carry-on and checked bag allowances as part of the membership perks. In 2026, savvy travelers also use the "bundle" options like The Works, which combines a carry-on and a checked bag into the ticket price for a lower total than buying them separately. Finally, always ensure your bag fits in the sizer at the gate; if your "free" personal item is too large, Frontier will charge an expensive "gate bag fee" that can be significantly higher than the online price.