Systems, methods, and devices are provided for a multiplexed serial media independent interface (110-1, 110-N, 210). One system for handling data includes a physical layer (PHY) circuit (102-1, 102-N, 202-1, 202-N) operating at a first rate including a number of ports (104-1, 104-P), a media access control (MAC) circuit (108, 208-1, 208-N) operating at the first rate including a number of ports, and a multiplexed serial media independent interface (110-1, 110-N, 210) between the MAC circuit (108, 208-1, 208-N) and the PHY circuit (102-1, 102-N, 202-1, 202-N) operating at a second rate, which is greater than the first rate. The interface (110-1, 110-N, 210) includes a number of conductors and is configured to communicate data between the MAC circuit (108, 208-1, 208-N) and the PHY circuit (102-1, 102-N, 202-1, 202-N) via four conductors per up to eight ports (104-1, 104-P) of the PHY circuit (102-1, 102-N, 202-1, 202-N).