An electrical connector assembly includes a coaxial connector structure having a center contact configured to be surface mounted to an upper surface of a circuit board at a board edge of the circuit board. The center contact extends along a contact axis in an axial direction. A shielded housing block extends rearward from the coaxial connector structure. The shielded housing block has a shielded chamber receiving a portion of the center contact with an open bottom extending along the upper surface of the circuit board. A shield member engages at least one of the coaxial connector structure and the shielded housing block. The shield member extends along at least a portion of the open bottom of the shielded chamber in the axial direction.