Abstract: A system for delivery of therapeutic and/or diagnostic agents into a living body includes a port assembly having a cannula extending from the mounting side, a port opening away from the mounting side and a resilient barrier between the port and the cannula. An access hub includes a connector positionable at the port for opening the resilient barrier. The access hub is movable in the port assembly, is engaged therewith through a resilient ring coupling and forms a seal with the resilient barrier, reducing the amount of volume to be primed. Inserters, both disposable and reusable, include the cannula insertion member as part of the assembly. A spring loaded port driver is operatively mounted within the housing with movement controlled by a latch. The driver includes a seat for receipt of a port assembly. The cannula insertion member is nonremovably fixed in a socket in the port driver in the disposable assembly.