The Justice Department plans to end its use of private prisons after officials concluded the facilities are both less safe and less effective at providing correctional services than those run by the government.

Deputy Attorney General Sally Yates announced the decision on Thursday in a memo that instructs officials to either decline to renew the contracts for private prison operators when they expire or “substantially reduce” the contracts’ scope. The goal, Yates wrote, is “reducing — and ultimately ending — our use of privately operated prisons.”

“They simply do not provide the same level of correctional services, programs, and resources; they do not save substantially on costs; and as noted in a recent report by the Department’s Office of Inspector General, they do not maintain the same level of safety and security,” Yates wrote.

In an interview, Yates said there are 13 privately run privately run facilities in the Bureau of Prisons system, and they will not close overnight. Yates said the Justice Department would not terminate existing contracts but instead review those that come up for renewal. She said all the contracts would come up for renewal over the next five years.