Some Air Force colonels will be eligible to remain in uniform for three years past their active-duty retirement time of 30 years, the service announced.

Beginning this month, the Line of the Air Force Colonel Continuation Board will look at the records of the 50 line officers who will face mandatory retirement between Feb. 1, 2018, and Feb. 1, 2019.

Normally, colonels not selected for promotion to one star must retire after 30 years of service.

With the Air Force’s announcement, eligible colonels can choose to remain on active duty for an additional three years, according to the Air Force. If an officer is selected, his or her chain of command will receive the notification for consideration.

All Line of Air Force specialty codes are eligible, and qualified officers would have been notified by Dec. 31.

“It can take 21 years to develop a line officer to become a colonel who may then serve up to 30 years,” Col. Jeff O’Donnell, Air Force Colonels Group director, said in the news release. “And as the Air Force is growing end strength, we need experienced leaders to serve and lead across the Department of Defense.”

The announcement comes as the Air Force deals with a shortage of field-grade officers, such as majors, lieutenant colonels and colonels, as well as pilots.

The Air Force has been trying various incentives to keep these skilled airmen in the service.

In September, the Air Force was at 92 percent manning for Line of the Air Force field-grade officers, and non-rated field-grade officers were at 74 percent. In December, the Air Force allowed a 100 percent promotion rate to major for qualified captains with exemplary conduct.