Devices, systems, methods and kits for releasably mounting a medical device on the body or skin of a user are provided. Embodiments include a holder or mounting unit or structure that retains a medical device in a fixed position on a body part of a user or host, such as on the surface of the skin, and/or provides physical and/or electrical coupling to one or more additional components which may be operatively positioned above and/or below the surface of the skin.
