Former U.S. House Speaker Dennis Hastert began his 15-month prison sentence Wednesday.
Hastert, who experienced a stroke in November 2014 and is said to have several other health problems, reported to the Minnesota-based Rochester Federal Medical Center in a wheelchair.
The former Republican lawmaker received a 15-month prison sentence in late April for violating bank reporting requirements. The bank violations were in connection with a hush money scheme to conceal past sexual misconduct dating back to when Hastert, 74, was a teacher and wrestling coach at Yorkville High School.
During his sentencing hearing, Hastert admitted to sexually abusing students.
"What I did was wrong and I regret it," he added. "They looked to me, and I took advantage of them."
Federal Judge Thomas Durkin, who gave Hastert a longer sentence than recommended by prosecutors, described the former politician as "serial child molester."
As part of his punishment, Hastert must also pay a $250,000 fine, be on supervised release for two years and undergo sex offender treatment.