The smallest wire size for which overcurrent protection is specified in the National Electrical Code (NEC) is 14 AWG (American Wire Gauge) copper wire. Overcurrent protection is specified to ensure safety and prevent overheating or fire hazards in circuits using this wire size or larger.
This means for wires smaller than 14 AWG, overcurrent protection specifications are typically not detailed in the NEC, while for 14 AWG wire and larger, such protection must be provided according to code requirements to match the wire ampacity and ensure safe operation.
Therefore, the answer is 14 AWG.
