Party president and Prime Minister Najib Tun Razak said the unanimous decision by the supreme council was taken as Muhyiddin and former premier Mahathir Mohammad's son Mukhriz Mahathir had appeared on the same stage with the opposition.
He said that MP Shafie Apdal's membership had also been suspended until the party's disciplinary board gets a report over the matter.
Muhyiddin and Shafie were dropped from Cabinet in July, .
In February this year, Muhyiddin, who is Pagoh MP, was suspended as party deputy president.