A delivery device includes a durable housing portion and a separable disposable portion that selectively engage and disengage from each other. The disposable housing portion secures to the patient-user and may be disposed of after it has been in use for a prescribed period. Components that normally come into contact with a patient-user or with an infusion medium, including a pump device, are supported by the disposable housing portion for disposal after the prescribed use, while the durable housing portion supports other components such as electronics for controlling delivery of the infusion medium from the reservoir and a drive device and drive linkage.
