Residual limb health and comfort of any person with limb loss of all levels is crucial to achieving maximum prosthetic use and function. There is currently inadequate data substantiating the impact of interface design on socket comfort, residual limb health and function. There are two alternative interface designs for the military and veteran above knee amputee that could provide answers to issues germane to above knee amputees such as moisture control, skin temperature and condition. The Dynamic Socket DS design is comprised of a flexible interface and minimal laminated rigid frame to reduce thermal layers, increase flexibility and comfort while retaining ischial containment. In contrast, a Sub-I design has significantly lower trim lines, without ischial containment compared with a traditional interface. However, these alternative designs could compromise overall function compared to the standard of care interface design. Therefore the focus of this clinical trial is to determine if the DS and Sub-I alternative interface designs will improve socket comfort, residual limb health and function compared to the standard of care IRC interface design.