A USB Type-C audio-visual adapter system includes a base module and an expansion module. The base module has a first housing with a first face and a second face, where the first face includes USB and A/V connectors and the second face includes a first expansion connector. The second face is offset inwardly from an edge of the first housing defined by a lip extending about the second face. The expansion module has a second housing with a first face that includes a second expansion connector, where the first face of the second housing is configured to be received within a recessed area formed by the lip of first housing to facilitate mechanical and electrical coupling of the first and second expansion connectors.