Gateside by TSA PreCheck brought back a pre-9/11 perk. Now it's scaling back.

A new Transportation Security Administration program that lets nonticketed TSA PreCheck members pass through security and access terminal gates has been rolled back to its original 13 airports, just weeks after expanding to hundreds of locations.

"Gateside by TSA PreCheck" initially launched in September at 13 U.S. airports to mimic a pre-9/11 airport experience at no extra cost. "Participants can use the program to accompany family members and loved ones to the gate, greet arriving passengers, enjoy airport dining and shopping, or experience the terminal without taking a flight," according to a TSA press release .

Members of TSA PreCheck can apply for a pass using their Known Traveler Number (KTN) to go through a participating airport's security checkpoint without an airline ticket, but will need a valid form of ID and proof of Gateside approval.

By Oct. 2, the program had expanded beyond the original 13 U.S. airports when the airport selection menu in the Gateside by TSA PreCheck application reportedly added hundreds more airports nationwide. But as of this week, the program was scaled back.

The TSA PreCheck program is an expedited screening service available at participating security checkpoints across the U.S. It's designed to make airport security screening faster and less cumbersome for approved travelers.

Travelers fill out a pre-enrollment form online, then schedule an in-person appointment with an enrollment provider to verify their identity, have their fingerprints and photo taken, and pay the enrollment fee.

With TSA PreCheck, eligible passengers are generally allowed to:

Keep their shoes on during airport screenings

Keep laptops and other large electronic devices inside their carry-on bags

Leave acceptable liquids in their bags rather than having to remove them for separate screening

Keep in mind that TSA PreCheck is only offered at U.S. airports. Children 17 and younger are allowed to go with you in the TSA PreCheck line as long as they're on the same reservation. Children 13 to 17 must have the PreCheck indicator on their boarding pass.

OK, so what exactly is Gateside by TSA PreCheck?

It's a program offered only to TSA PreCheck members that allows them to travel through airport security using the TSA PreCheck lanes all the way to the boarding gate without an airline ticket. This is useful for parents who want to accompany children, those helping older relatives navigate an airport or families who want to spend more time together before a flight.

TSA PreCheck members can click the Apply button on the Gateside by TSA PreCheck website . They must apply one to three days before their planned visit.

Members will not receive a digital or paper pass. They must present an acceptable form of ID to a TSA officer and may also need to display their approved Gateside status on their mobile device.

Which airports still offer Gateside TSA PreCheck?

The following 13 U.S. airports currently participate in the Gateside by TSA PreCheck program, according to the TSA website:

John Glenn Columbus International Airport (CMH) in Ohio

Dallas Fort Worth International Airport (DFW) in Texas

Detroit Metropolitan Wayne County Airport (DTW) in Michigan

Wichita Dwight D. Eisenhower National Airport (ICT) in Kansas

Indianapolis International Airport (IND) in Indiana

Harry Reid International Airport (LAS) in Nevada

Los Angeles International Airport (LAX) in California

Bill and Hillary Clinton National Airport (LIT) in Arkansas

Will Rogers International Airport (OKC) in Oklahoma

San Diego International Airport (SAN) in California

Salt Lake City International Airport (SLC) in Utah

What has the Gateside experience been like so far?

On Oct. 2, Norfolk and Newport News-Williamsburg airports in Virginia were both included on the list beyond the original 13 airports. In the first four days of the expanded program, 31 people requested and used the new gateside passes at Norfolk, the airport's vice president and chief marketing and communications officer, Chris Jones, told WAVY .

"TSA has told us that the Gateside by TSA PreCheck program is on hold indefinitely aside from the 13 airports in the pilot program," Jones said.

Denver International Airport was also temporarily included in the Gateside program, KUSA reported. "TSA recently returned Gateside by TSA PreCheck operations to the original 13 participating airports, at least for the time being," the airport said in a statement to CNN .

In a statement to Yahoo, a TSA spokesperson confirmed that Gateside by TSA PreCheck is currently being assessed at 13 airports nationwide. "TSA is evaluating participation levels and assessing operational impacts," the spokesperson said. "This assessment is proving that TSA's security posture remains strong while delivering innovative benefits to PreCheck customers."

The agency did not specify why the program was scaled back or when it might expand to additional airports.

Some travelers at participating airports have reported relatively smooth experiences using Gateside. One Reddit user said they experienced only a minor delay at John Glenn Columbus International Airport (CMH) in Ohio.

"The only 'hiccup' in the process is the TSA agent at the PreCheck line was unfamiliar with Gateside, but the person he called over for help told them what to do and it only delayed me by about a minute," the user wrote.

A post on OneMileAtaTime.com similarly noted that the only real hang-up was that the TSA agent wasn't familiar with the program. "If you do this, make sure you have your TSA log in on your phone, so that you can access your confirmation at the airport," the user wrote.