A cable card assembly includes a circuit card having cable conductors at a cable end and cables terminated to the circuit card having signal conductors and ground shields surrounding the corresponding signal conductors to provide electrical shielding for the signal conductors. The signal conductors include exposed portions terminated to corresponding cable conductors. The cable card assembly includes a ground bus electrically connected to the ground shields. The ground bus includes a molded body having tunnels receiving the exposed portions of corresponding signal conductors. The molded body is contoured to control impedance along the exposed portions of the signal conductors.