Although bills have been introduced in Congress in the past to reduce the amount of time served on federal sentences, none have passed.
Under the Federal Sentencing Guidelines, which apply to all crimes committed since 1987, parole is abolished and inmates must do 85% of their sentence.
The last bill to be introduced, in 2005, was LERA, the Literacy, Education and Rehabilitation Act. It's chief sponsor was Rep. Bobby Scott of Virginia. It would have allowed another 60 days per year to be deducted from federal sentences if the prisoner participated in certain educational, vocational, treatment, or work programs. The bill only gathered five cosponsors and never made it out of committee.
I'm not aware of any current plans to reintroduce the bill, although you might contact Rep. Bobby Scott and inquire if he plans to try again in the new session of Congress.