An implantable neurostimulation system includes both implantable and external components. Electrical connectivity between the external and implanted components is achieved through a plurality of feedthrough pins located within an insulative wall of a percutaneous port embedded in the skin. The percutaneous port has the general shape and appearance of a small thimble, embedded in the skin with its open end facing outwardly from the skin surface, and with its closed end located below the skin surface, thereby forming a cavity or dimple in the skin. Various plugs or cartridges can be removably inserted into the cavity of the percutaneous port, in various orientations, to facilitate appropriate connectivity between the external and implanted components of the system through selected ones of the feedthrough pins. A mesh edging secured around the periphery wall of the port promotes tissue ingrowth and vascularization, thereby forming a percutaneous seal around the port that prevents infection.