A connector assembly includes a cover assembly and a feedthrough assembly that couples with the cover assembly. The cover assembly receives a connector end of a lead having lead contacts, and aligns the lead contacts with pockets or apertures of the cover assembly. The feedthrough assembly may include feedthrough contacts in the form of feedthrough pins at or above a surface of a feedthrough substrate, or conductive vias on the surface of the substrate. Electrical contacts configured as leaf spring contact assemblies, torsion spring contacts, or torsion spring contact assemblies are permanently attached to the feedthrough contacts. When the cover assembly and feedthrough assembly are coupled, contact tabs of the electrical contacts are positioned in the pockets or apertures of the cover assembly. Upon complete seating of the cover assembly and feedthrough assembly, the contact tabs are compressed into contact with the lead contacts.