Efron, 25, is best known for his roles in the "High School Musical" franchise and the movie musical "Hairspray." He will soon be seen in the big-screen drama "Parkland."
The actor entered rehab last spring, but is now "doing great," a source told People.com Tuesday.
"He's taking care of himself and it shows," said the source, whose name was not reported.
"He's healthy, happy and not drinking," an insider told E! News. "He's taking time to focus on working."