Disclosed herein is an implantable medical device including a housing, a header, a connector port, and a collet assembly. The header can be arranged with the housing. The connector port can be arranged within the header and configured to couple an implantable lead to the header. The collet assembly can be arranged within the connector port and configured to frictionally engage a portion of the implantable lead and to secure the implantable lead with the header in response to insertion of the portion of the implantable lead into the connector port.