A receptacle assembly includes a receptacle housing and a contact module received in the housing. The contact module includes a tray having a cavity defined by inner surfaces of the tray. Ground inlays are received in the cavity along corresponding inner surfaces. The ground inlays have ground slats and ground flanges extending from the ground slats. A frame assembly is received in the cavity of the tray between the ground inlays. The frame assembly is electrically shielded by the ground inlays and has a plurality of receptacle signal contacts arranged in differential pairs carrying differential signals. The ground slats extend along opposite sides of corresponding pairs of the receptacle signal contacts and the ground flanges extend between pairs of the receptacle signal contacts.