Federal inmates serve just 65 percent of their sentence.

For sentences of 12 months and longer, federal inmates are permitted only a 15 percent sentence reduction for good behavior.

For sentences of 12 months and longer, federal inmates are permitted only a 15 percent sentence reduction for good behavior. There have long since been rumors that federal inmates are only required to serve 65 percent of their sentence. These rumors are unfounded. Federal inmates serving sentences of more than 12 months (but less than a life sentence) are only permitted a 15 percent sentence reduction. This is called "good conduct time."

This is in accordance with the First Step Act of 2018. Vox reports that "Inmates who avoid a disciplinary record can currently get credits of up to 47 days per year incarcerated. The law increases the cap to 54, allowing well-behaved inmates to cut their prison sentences by an additional week for each year they’re incarcerated."

Other sources concur. The website for a group of federal defenders states, "For sentences of twelve months and one day or longer, a client is eligible for good time credit of up to 15 percent, as long as there have been no disciplinary problems."

A proposed Florida bill, Senate Bill 572, was set to reduce the non-violent crime serving requirement to 65 percent. However, in March 2020, this bill was "indefinitely postponed and withdrawn from consideration", according to the Florida Senate.