A refill port for an implantable device with integral refill instrument placement detection includes a pierceable septum (30) and a detector (38). The pierceable septum is disposed on the refill port for admitting a refill instrument has a first outer surface (46) at least a portion of which is exposed outside the refill port and a second inner surface (48) at least a portion of which is exposed inside the refill port. The detector is disposed inside the refill port with respect to the second inner surface of the pierceable septum for determining the placement of a refill instrument within the refill port. The refill port can be provided on a refillable implantable drug delivery pump having control electronics so that the detector can trigger pump test features of the control electronics upon placement or removal of a refill instrument from the port.
