An endoprosthesis includes a plurality of struts defining a flow passage. At least one strut includes (a) a body comprising a bioerodible material and having a thickness and (b) a coating overlying the body. The coating includes a plurality of regions that allow physiological fluids to contact a plurality of corresponding areas of the underlying body when the endoprosthesis is implanted in a physiological environment. The plurality of regions are sized and arranged so that the contacted areas of the body erode substantially through the body in the thickness direction while the coating remains on the body when the endoprosthesis is implanted in the physiological environment.
