After the Mobil Superleague was disbanded in favour of the new Commonwealth Bank Trophy, Plummer became the founding coach of the new Melbourne Phoenix team, which took many of the players from the former Pumas, and successfully coached them to the inaugural premiership. She was also appointed coach of the Australian youth team and took them to several successes. She subsequently resigned as coach of the Phoenix at the beginning of the 1999 season in order to take up a position as head netball coach at the Australian Institute of Sport. While in this role, she was integral in the campaign to add the AIS Canberra Darters to the national competition.