Abstract: A passive electrical transponder may be encoded with a code corresponding to medical information, and the transponder directly transplanted in a patient's underarm area. Medical devices may also carry transponders to identify them for use with the system of the present invention. The code may be accessed with an electromagnetic hand held reader which is brought into proximity of the transponder. The medical information may itself be directly encoded into the transponder, or a code used which is then keyed to a corresponding data entry in a data bank or computerized data base accessible over telecommunication lines. With this invention, medical information may be reliably and confidentially recorded, maintained, and accessed with minimal patient involvement in order to achieve a high degree of reliability and accuracy.