Bill Cosby used to be America's dad, Dr. Cliff Huxtable. Now he's serving three to ten years for indecent behavior.

Somehow, these two facts are becoming one. According to a report in Radar Online, The Cos has been pretending he's Dr. Huxtable and treating patients behind bars.

“He is accepting appointments from inmates to help diagnose anything from a cold to obesity,” a source told Radar Online. “If he thinks they’re incurable, he refers them to the infirmary with a ‘preliminary diagnosis.’

He told us that he wore a bedsheet like an ‘apron’ to get into character,” the source confided. “He said his medical skills are ‘a tad rusty’ since he played Dr. Huxtable, but he’s still ‘hip’ to the ‘role.’

The prison staff, many of whom grew up watching The Cosby Show, have been humoring the 81-year-old.

An inmate told a relative “he was told to follow along with whatever Cosby says — play along. He’s old, so the prison staff just want no problems. He hopes to get a job in the infirmary, this way they keep him in there.”

Said the source, “The prison does not intend on moving him, so we just play along to make him feel better!”