GFCI Requirements

Ground-Fault Circuit Interrupter Standards

Where GFCIs Are Required

Ground-fault circuit interrupter protection is required by the National Electrical Code® for receptacles in areas where a water source is present. This includes all wet or damp locations.

Federal Code for Dwellings

GFCI protection is required for 15-amp and 20-amp, 125-volt receptacles in:


  • All Areas


Garages & Accessories

  • Includes areas used for storage or work



  • Receptacles installed under the eaves of roofs
  • Multifamily dwellings with individual entrances at grade level must have at least one GFCI-protected receptacle


Crawl Spaces

  • Spaces at or below grade level
  • Areas where heating, AC and refrigeration equipment is installed
  • Includes 120-volt lighting outlets


Unfinished Portions of Basements

  • Unfinished areas not intended for habitable rooms 
  • Receptacles for permanent smoke detectors or burglar alarms do not require GFCI protection


Kitchen Countertop Surfaces

  • Receptacles serving countertop surfaces
  • Required for dishwasher outlets



  • Receptacles within 6 ft. of the top inside edge of the bowl of a sink



  • All areas
  • Includes boat hoist outlets not exceeding 240 volts


Bathtubs or Shower Stalls

  • Receptacles within 6 ft. of the outside edge of a bathtub or shower stall
Laundry Areas

  • All areas

Federal Code for Non-Dwellings & Other Structures

GFCI protection is required in single-phase receptacles rated 50 amps or less, not exceeding 150 volts to ground, and 3-phase receptacles rated 100 amps or less, not exceeding 150 volts to ground.


  • All areas


  • All areas



  • All areas
  • Receptacles must be installed within 25 ft. of heating, AC and refrigeration equipment
  • Receptacles must be readily accessible from the rooftop’s surface area



  • All areas



  • All receptacles within 6 ft. of the top inside edge of the bowl of a sink
  • Not required for industrial laboratory sinks where the removal of power would introduce a greater hazard


Indoor Wet Locations

  • All areas


Locker Rooms

  • All areas with showers



  • Includes service bays and similar areas
  • Does not include show rooms and exhibition halls


Crawl Spaces

  • All areas


Unfinished Portions of Basements

  • All areas



NEC® GFCI Requirements

The National Electric Code drives your business operations. It is our safety guide to electrical product and component installation and maintenance. Regular revisions, including those for ground-fault circuit interrupters, are necessary to keep up with our industry’s demands.

  • Revisions are made every three years
  • The latest standards were released in 2017
  • The next codes and standards release is 2020 
  • Anyone can submit a change via public input 

GFCI Code Changes from 2017

Revisions to dwellings:

  • Define distance between a water source and receptacles that require GFCI protection as “the shortest path the cord of an appliance connected to the receptacle would follow without piercing a floor, wall, ceiling, or fixed barrier, or passing through a door, doorway, or window.”
Revisions to non-dwellings:

  • Require GFCI protection on single-phase receptacles 50 amps or less, rated 150 volts to ground or less, and three-phase receptacles 100 amps or less, rated 150 volts to ground or less. 
  • Expand GFCI requirements to crawl spaces at or below grade level and unfinished areas of basements.


Ground-fault circuit interrupters, GFCIs or GFIs, are safety devices built into outlets that protect against electrical shock. Their circuitry monitors electrical input. When a ground fault occurs, the GFCI quickly—in a fraction of a second—shuts off the power.

Ground Fault Causes
  • Operating equipment in wet or damp areas 
  • Running faulty or leaking tools and appliances                                                            
  • Using damaged cords or wiring                       

Feed-Through Protection

GFCI outlets protect all outlets on the same circuit, as well as connected tools and appliances.


The latest UL Standards require GFCIs to be self-testing. This requirement began in 2015.


There is no difference between GFCI and GFI protection. Ground-fault circuit interrupters are commonly referred to as ground-fault interrupters.


Arc-fault circuit interrupters are different. AFCIs protect against fires caused by arcing faults that come from faulty or damaged wiring.


GFCIs are different than circuit breakers in that they are more sensitive. On their own, circuit breakers only protect against overloads and resulting fires. GFCIs, however, protect against electrical currents that are too low to trip breakers but are more than enough to cause injury. Having both GFCI and circuit breakers helps safeguard against electrical shock and fires.