The 67-year-old said he has never been in rehab before, but believes he's sufficiently motivated to beat the wine and Vicodin.
"My levels of use are nowhere near the worst you hear about these days -- I could easily have continued functioning at a good level ... for a while," he said. "But my use would have progressed, I would have been in deeper trouble, and I didn't want to tolerate that."
He did not disclose which facility he was checking into, or for how long.
Carlin has no concert dates listed on his Web site, georgecarlin.com, and has wrapped up a swing through theaters and bookstores in recent weeks to promote his latest boundary-pushing book, "When Will Jesus Bring the Pork Chops?"