The former "Prison Break" co-star was expected to stay at the Tarzana Treatment Facility for five months after he checked in last week, following his release from jail.
"He stayed at the facility for a couple of hours," a source close to Garrison told E! News. "Because of the work he did as a substance-abuse program leader while he was incarcerated, they said he had already served his time in regards to rehabilitation so it would be redundant considering the work that he had already completed. ... He's taking every day to assimilate back into normal life, day-to-day existence. He appreciates everything so much, the sunshine, food is amazing."
California Department of Corrections spokesman Terry Thornton told E! Garrison will be on parole for between two and three years.