Embodiments of the present invention relate to an implantable device housing assembly, for use in, for example, implantable prosthetic devices. In one aspect, the present invention provides a housing for an implantable device comprising a body portion and a sealing flange. The body portion includes a cavity in which electronic components are disposed on an open side thereof, and at least one feed-through which provides electrical connections between the electronic components and the exterior of the device. The feed-through includes interior and exterior connection points, which are accessible during assembly of the device from a first side of the device. The sealing flange operatively seals the cavity so as to form a sealed housing. A method of forming a sealed housing for an implantable device is also provided.