Medical leads include a lumen body at an end of the lead, and the lumen body includes multiple filar lumens. The lumen body is joined to a lead body, and electrical connectors are longitudinally spaced along the lumen body. Filars within the filar lumens are directed through filar passageways within the lumen body to attach to the electrical connectors on the lumen body. The filar passageways may be aligned with the filar lumens, and slots within the electrical connectors may be aligned with the filar passageways to facilitate assembly. The lumen body may provide additional stiffness to the end of the lead where the lumen body is located to facilitate lead insertion into the medical device. The filar lumens of the lumen body may have a longitudinally straight configuration so that the portions of filars within the filar lumens are held in a longitudinally straight configuration.