Flying ultra-low-cost airlines like Spirit and Frontier means a bare-bones experience in many ways, not all of them expected. While most customers know they’ll be shoehorned into no-legroom seats in exchange for rock-bottom ticket prices, they are often surprised to discover a less-publicized tradeoff: Neither Spirit nor Frontier participates in the TSA’s PreCheck program for trusted travelers.

That’s an especially glaring drawback today, in light of the TSA’s recent inability to efficiently manage security at the nation’s airports, and the resulting long lines at screening checkpoints. Enrolling in PreCheck is the only reliable way to minimize the wait times, although it’s hardly the definitive solution to the problem.

Today, travelers flying Spirit and Frontier, even if they’re enrolled in PreCheck, cannot take advantage of the expedited-processing lanes, because the software used by the two carriers isn’t linked to the TSA’s software. By July 31, that missing link will be established, allowing both carriers to participate in the program.

Frontier CEO Barry Biffle this week pledged to join PreCheck immediately; Spirit, on the other hand, will defer its participation until some time this fall.

So, Frontier flyers can look forward to a bit of relief during the latter half of the summer travel crush. Spirit flyers will have to wait.

Reader Reality Check

Are you enrolled in PreCheck?

After 20 years working in the travel industry, and almost that long writing about it, Tim Winship knows a thing or two about travel. Follow him on Twitter @twinship.

This article first appeared on SmarterTravel.com, where Tim is Editor-at-Large.