Nearly 20 years after airline passengers were first required to remove their shoes for security, the policy is being phased out.

The Transportation Security Administration (TSA) has plans in motion to let travelers retain their shoes while passing through the main security lines at numerous major airports nationwide, according to two sources who spoke with ABC News.

Last week, TSA personnel across the nation were alerted via an unexpected memo stating that a new policy is set to be implemented. This change permits all passengers to keep their shoes on during screening at many airports starting this Sunday.

As per the memo, the initiative is to be expanded to include all U.S. airports in the near future. Previously, the privilege to keep shoes on during the screening process was predominantly reserved for those in the TSA PreCheck lanes.

The transportation agency has spent years looking for an innovative way to allow passengers to move faster through the security checkpoints.

Passengers who trigger the alarm at the scanners or magnetometers, however, will be required to take their shoes off for additional screening, according to the memo.

This is a major shift since TSA began requiring passengers to take their shoes off in 2006.

The policy came five years after Richard Reid tried to blow up an American Airlines flight from Paris to Miami with explosives packed in his shoes. The explosives failed to detonate and Reid was held down by fellow passengers and the flight crew.

ABC News has reached out to TSA for a comment.