Radel pleaded guilty to cocaine possession in November and was sentenced to one-year probation. He announced he would take a leave of absence after his sentencing, calling the incident a "wake up call."
More from the Associated Press: Congressman Trey Radel of Florida is expected to talk about his political future a month after he pleaded guilty to cocaine-possession charges.
The freshman Republican is set to address a news conference Thursday evening in his Cape Coral office.
His spokesman, Dave Natonski, says Radel completed in-patient treatment at a Naples rehabilitation center Thursday.
On Nov. 20, Radel pleaded guilty to a misdemeanor charge of cocaine possession and was sentenced to a year of probation. He admitted to purchasing 3.5 grams of cocaine from an undercover officer in Washington on Oct. 29.
Several GOP leaders, including Gov. Rick Scott, have asked him to resign.
Radel had been in office for 10 months when he was charged. His district includes the Gulf Coast cities of Fort Myers and Naples.