In this paper, a multilayer patch antenna is proposed for implantable applications at the 401-406 MHz Medical Device Radiocommunications (MedRadio) and 433-434.8 MHz Industrial Scientific and Medical (ISM) bands. The antenna is composed of a spiral split extended into two layers to obtain miniaturization and coupled to an outer rectangular split ring to broaden the antenna bandwidth and increase its gain by 1 dBi. The proposed antenna has a relatively small size and good radiation characteristics for data transfer over 4 meters.