The paper deals with the supervisory control used in a Vehicle System Controller (VSC) of a Parallel Hybrid Electric Vehicle (PHEV). A description of the torque distribution algorithm that determines the prorated amount of torque demanded of each of the tractive devices to meet the driver's demand and the energy management scheme is given. The PHEV hybrid operating modes and PHEV dynamic model are presented and simulation results are shown depicting the seamless transitions from one hybrid mode to another as coordinated by this supervisory controller.