In one aspect, transitioning among replication modes in a storage system is provided. An aspect includes during an active replication session in which a first replication mode is performed, validating a precondition for transitioning to a second replication mode that is different from the first mode of replication. An aspect further includes suspending data flow for the active session, establishing a base snap set pair for a mode transition cycle, and preparing for the transitioning including updating, for the mode transition cycle, the base snap set pair on both a source system and a target system of the storage system, and creating a snap set against an active snap set on the target system as a mode transition cycle snap set. An aspect further includes implementing the mode transition cycle, and entering a replication session, upon completion of the mode transition cycle, for the second mode of replication.