An improved apparatus and method is provided for supportably mounting an implantable hearing aid device to a patient's skull. The apparatus includes a support member adapted for supporting a hearing aid device and a plurality of mounting legs extending laterally from the support member in differing directions. The apparatus further includes a mechanism for use in conforming the mounting legs to the topology of a patient's skull. In one arrangement, the mechanism includes a plurality of guide legs having a reduced yield strength in comparison to the mounting legs. The reduced yield strength guide legs may be more readily conformed to the topology of the patient's skull to provide a mounting leg profile. Accordingly, the mounting legs may be deformed to match the profile of the guide legs such that a conformal fit between the apparatus and the patient's skull may be achieved.