* Local Authorities Having Jurisdiction (AHJs): These are the primary enforcers. This could be a city, county, or other local government agency responsible for issuing building permits and inspections. They adopt the NEC and often add their own local amendments or interpretations. They conduct inspections during construction and may cite violations.
* State and Federal Agencies (Indirectly): While not directly enforcing the NEC, state and federal agencies often have regulations that reference or incorporate the NEC, particularly in certain industries like healthcare or industrial settings. Their inspections might indirectly lead to NEC compliance being checked. For example, OSHA (Occupational Safety and Health Administration) might cite violations relating to electrical safety that stem from non-compliance with the NEC.
In short, the NEC itself is not law. It's a standard that's adopted and enforced by various local authorities. The specifics of enforcement vary widely depending on location and the specific project.