CHICAGO (AP) — Imprisoned Illinois ex-congressman Jesse Jackson Jr. is on track to be released from federal prison earlier than first expected because of his completion of a drug or alcohol treatment program.

The Chicago Sun-Times reports Jackson is now scheduled to be released Sept. 20, 2015.

The Chicago Democrat is serving a 2 1/2-year sentence after admitting to illegally using campaign money. The 49-year-old Jackson admitted spending $750,000 of donors’ money on more than 3,000 personal items. He was scheduled for release Dec. 31, 2015.

Bureau of Prisons spokesman Chris Burke would not say what treatment Jackson has received, adding an inmate’s programming history is not discussed by prison officials.

(Copyright 2014 The Associated Press. All rights reserved.)