An implantable microstimulator (10) configured to be implanted for tissue stimulation employs a self-contained power source (16) and a bi-directional RF telemetry link (48) for allowing data-containing signals to be sent to and from the implantable microstimulator (10) from at least two external devices (39,40). Further, a separate electromagnetic inductive telemetry link (38) allows data containing signals to be sent to the implantable microstimulator from at least one of the two external devices (39).The implantable microstimulator, comprises:an hermetically-sealed housing (213)；a first electrode (22) and a second electrode (24) for stimulating tissue, each electrode external to the hermetically-sealed housing；an antenna (18) within the hermetically-sealed housing； andtelemetry circuitry coupled to the antenna for receiving data-containing signals from at least one external device (39,40,60), said telemetry circuitry comprising:a first telemetry receiver for receiving data in accordance with a first telemetry scheme, anda second telemetry receiver for receiving data in accordance with a second telemetry scheme.
