A replacement heart valve and method of treating valve insufficiency includes an expandable frame configured to engage a native valve annulus. A valve body is coupled to the frame. The valve body can include a leaflet portion and possibly a skirt portion. A portion of the frame has a foreshortening portion configured to longitudinally expand when urged to a radially compacted state and longitudinally contract when urged to a radially expanded state. In one embodiment the valve skirt is attached to the frame so that it can adapt to changes in the length of the frame. A delivery device in some embodiments can use one or more coverings, such as sheaths, to controllably release the replacement heart valve at a native heart valve.