Good time credit is one of the most misunderstood parts of the sentencing system, and the way it actually works surprises most families.
In the federal system, good time is not something an inmate earns gradually through good behavior. It is granted upfront at the beginning of the sentence and can only go in one direction from there. The Bureau of Prisons applies a credit of up to 54 days per year of the sentence imposed, which works out to roughly 15 percent off the total sentence from day one. That credit is already built into his projected release date when it gets calculated. The only way it changes is if he picks up disciplinary infractions that result in good time being taken away. So the goal is simple: protect what he already has by staying out of trouble.
Beyond standard good time, there is one program in the federal system that can take a full year off a sentence, and it is worth knowing about if your husband qualifies.
It is called RDAP, the Residential Drug Abuse Program. It is an intensive nine to twelve month treatment program offered at select federal facilities, and successful completion can result in up to twelve months off the sentence plus early transfer to a halfway house. The catch is that eligibility requires a documented substance abuse problem that predates the incarceration. It cannot be fabricated after the fact. If your husband had a genuine history with drugs or alcohol before he came in, his case manager needs to know about it and he should be screaming from the rooftops to get into RDAP.
Have him talk to his case manager about both his current good time balance and his RDAP eligibility. Those two conversations are the most valuable ones he can have right now in terms of managing his release date.