An upper extremity prosthetic device is provided that comprises three main components, namely, an arm cuff, a forearm section and a distal connector. The arm cuff is adjustable to accommodate lower arms of different sizes. The forearm section may be constructed in certain limited sizes to accommodate different sized forearm residual limbs. The distal connector is designed to connect to any of the forearm section configurations, and the distal connector enables any terminal device to be attached to the connector. The components may be mixed and matched in various combinations to fit the physical dimensions of virtually any amputee. The interchangeable parts will accommodate a wide range of residual limb geometries, overall sizes and lengths. Embodiments of the present invention minimize the need for time and resource-intensive customized fitting and create an affordable, relatively low-cost prosthetic interface.