Â No deputy prime minister has been appointed.
Muhyiddin resigned after conceding he had lost the majority of lawmakers.
The prime minister and his cabinet ministers must take and subscribe to the oath of office and allegiance as well as the oath of secrecy in the presence of the Yang di-Pertuan Agong before they can exercise functions of office.
Malaysia has one of the world's highest infection rates and deaths per capita, with daily cases breaching 20,000 this month despite a seven-month state of emergency and a lockdown since June.
The prime minister would usually be the leader of the party winning the most seats in a general election.
There are in total of 8 Prime Ministers up until today.