A valve that includes an expandable valve body defining a lumen and a longitudinally moveable obstructer retained within the lumen of the valve body between the proximal and distal ends of the valve when the valve is in an expanded configuration. The valve, in the collapsed configuration, is delivered to a native valve site by a catheter where the valve body is expanded to anchor the valve at the valve annulus and the collapsed obstructer is subsequently expanded so that the valve is in the expanded configuration.
