Niki Lauda has left Vienna's general hospital after a three month recovery from a lung transplant.
"Yes, Niki Lauda was discharged from the AKH and now he goes into rehabilitation," professor Walter Klepetko told Osterreich newspaper.
A few days ago, the Mercedes team chairman and F1 legend called Lewis Hamilton on the phone and told the championship leader that doctors had done a "perfect job".
It is believed 69-year-old Lauda's new lung works well.
Asked how Lauda's period of formal rehabilitation will proceed, professor Klepetko revealed: "It will be especially for Niki's physical fitness. This is typical after such a long period in hospital."
As for whether everything is functioning well with the lung, he added: "I'm more than satisfied with the result, and believe me, that's good.
"Luckily, we never had big problems at any time."
Osterreich said Lauda's rehabilitation will last for several weeks.
