Abstract: According to one aspect of the invention, implantable or insertable medical devices are provided which can delay release of one or more therapeutic agents for a predetermined time after implantation in a subject. In various embodiments, a therapeutic agent delivery profile of this type is provided by employing a temporary barrier layer which initially permits little to no release of the therapeutic agent, but which layer permits much greater release levels after a predetermined period of time. Other aspects of the invention relate to methods of forming such devices and to methods of using such devices.