Abstract: A connector assembly for an implantable medical device including a casing includes a header having a receptacle with an electrical contact for engageably receiving an electrical terminal on a proximal end of a lead and a fastener assembly for simultaneously releasably clamping the lead to the header within the receptacle and firmly attaching the header to the casing. The header is mounted on the casing and has a distal notched region with an upper surface and a first channel in its upper surface aligned with, and being a partial extension of, the receptacle. The fastener assembly includes a lead-lock component engageably received within the notched region of the header and with a second channel therein which is aligned and juxtaposed with the first channel, the channels taken together being an extension of the receptacle. A fastener system firmly mounts the lead-lock component to the header at the notched region.