Disgraced politician Anthony Weiner reported to prison Monday to begin serving a 21-month sentence for sending lewd messages to a high school student.
The former Democratic congressman from New York was dropped at the Federal Medical Center, Devens in Massachusetts, a prison spokesman said.
The facility offers treatment for sex offenders and sex addicts.
It is the same prison where Boston Marathon bomber Dzhokhar Tsarnaev completed his first two years of imprisonment.
Weiner, who was once a favored candidate for New York City mayor, spent his last day as a free man visiting his father.
He was driven to the correctional facility about 40 miles from Boston by his brother, Jason.
Weiner was sentenced to prison in September. He sobbed in court and told Judge Denise Cote of the Southern District of New York he had been "a very sick man for a very long time."
In announcing his sentence, the judge said, "This is a serious crime that deserves serious punishment."
He must register as a sex offender upon his release.
Weiner acknowledge he was a sex addict and was undergoing individual and group counseling.
He was accused of sending obscene material to a minor. Prosecutors said he had asked the 15-year-old girl three times last year to perform a sex act while naked and share it with him on social media.
The girl told him her age, prosecutors said, but that did not deter him.
Weiner has a tawdry history of sexting scandals.
He resigned his congressional seat in June 2011 after posting lewd photos of himself. Two years later, his mayoral campaign was derailed after a second incident.
His estranged wife, top Hillary Clinton aide Huma Abedin, has filed for divorce. They have a 5-year-old son.