The Belgrave train line has been suspended after a person was hit by a train in Bayswater on Wednesday 24 January.
Buses will replace trains between Ringwood and Upper Ferntree Gully, Metro Trains said, with replacement buses set to take over 60 minutes to arrive.
A train service will operate between Flinders Street and Ringwood, with delays to the service.
Commuters are advised to allow extra travel time.
