No inmates will be released under the revised guidelines until November 2015, the commission said. Congress has until this November to change the decision.
The commission, an independent judicial agency, said all decisions on early release will be reviewed by a judge with prosecutors being given an opportunity to object. But it is somewhat broader than the guidelines sought by Attorney General Eric Holder, who argued that only inmates who have not committed violent crimes and are not linked to major drug organizations should be eligible.
"This amendment received unanimous support from commissioners because it is a measured approach," Judge Patti B. Sarisn, the commission's chairwoman, said in a statement.
A total of 46,920 inmates -- more than one-fifth federal prisoners -- are believed to be eligible for early release under the commission's guidelines. Holder has already advised federal prosecutors against seeking mandatory sentences for non-violent drug offenders who are not part of major trafficking organizations.
The commission estimates that about one-quarter of eligible inmates would be released in the year after November 2015. and another quarter would still be behind bars five years later.