An expandable medical device (34) is mounted onto an expansion member (12) so as to ensure reliable and accurate placement of the device within a vessel or passageway. An expandable device such as a polymeric stent is mounted to an expansion member so as to prevent slippage of the polymeric stent relative to the expansion member during delivery while also exhibiting a low profile allowing for passage through the vasculature. A polymeric stent having a latticed structure is placed on an expansion member and a constraining member (52) such as a tube is then placed around the stent. The constraining member retains the stent in proximity to the expansion member. The constraining tube having the expansion member and stent therein is placed in a heating element (54) whereby when the expansion member partially inflates it nests within the lattice of the stent.
