The over-the-wire interlock attachment/detachment mechanism includes a cylindrical lock receiving section of a small diameter attached to an implantable medical device such as a blood clot filter, a stent, or a septal occluder. This cylindrical lock receiving section has a plurality of spaced, curved cutouts to receive both the guide fingers and contoured locking fingers formed on a cylindrical locking section. The locking fingers are angled outwardly from the cylindrical body of the cylindrical locking section, and are moved inwardly into engagement with the curved cutouts of the cylindrical lock receiving section by a sheath which slides over the cylindrical locking section or other suitable operator.