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Changes to the NEC

A rich history and rigorous review process

In 1897, NFPA 70®National Electrical Code® (NEC®), set the foundation for—and remains the world’s leading authority on—electrical safety in residential, commercial, and industrial occupancies. Learn more about new changes made to the 2023 and 2020 editions below.

What’s new in the 2023 NEC®?
The 2023 NEC® was reorganized to consolidate all the code’s defined terms into an expanded Article 100 to help users locate critical content more quickly. They are many other changes and new requirements, which include:
  • Residential Electrical Systems: Addresses ground-fault circuit interrupters (GFCI) for specific appliances, emergency disconnects, 10-ampere branch circuits, and more.
  • Commercial and Industrial Electrical Systems: Includes requirements for the use of “replacement panelboards,” arc-fault circuit interrupter (AFCI) protection, disconnecting means in sight of luminaires using double-ended lamps to include the LED type, and other considerations.
  • Alternative Energy Systems and Energy Management: Addresses the interconnection of distributed on-site power supplies with electric utility supplies, the delineation between storage battery, emergency storage, and photovoltaic electric systems, and more.
  • Never-before Covered Systems and Equipment: Covers Class 4 fault-managed circuits, hazardous locations in commercial and industrial cannabis production facilities, equipotential bonding in areas with “splash pads,” and other requirements.

Learn more about the 2023 NEC® changes.


What’s new in the 2020 NEC®?
The 2020 NEC® featured important changes related to emergency disconnects, ground-fault circuit interrupter protection, surge protection, and a myriad of other topics related to electrical safety, including:
  • Exterior Emergency Disconnects: Helps to improve electrical safety for emergency responders at one- and two-family dwelling installations.
  • Deenergizing Panel Boards: Revises service disconnect rules to help increase electrical worker safety.
  • Marinas and Boatyards: Updates ground-fault protection and leakage-current measurement device requirements.
  • Power Over Ethernet: Adapts NEC requirements to meet the installation practices of new and evolving technologies.
  • Conducting Load Calculations: Modernizes the tables currently in use for calculations to reflect improvements in energy efficiency.
  • Reorganization of Article 310: Includes new user-friendly numbering for important ampacity tables
  • Exposed Cables and Conductors: Adds new general requirement covering cables and conductors installed exposed on ceiling surfaces and sidewalls.

For a deeper dive into the 2020 NEC® changes, check out the NFPA Journal® highlights.

How to identify new changes
The 2023 NEC® and 2020 NEC® both include revision symbols identifying changes from the previous edition. Text revisions are shaded. The Δ before a section number indicates that words within that section were deleted and a Δ to the left of a table or figure number indicates a revision to an existing table or figure. When a chapter was heavily revised, the entire chapter is marked throughout with the Δ symbol. Where one or more sections were deleted, a is placed between the remaining sections. Articles, annexes, sections, figures, and tables that are new are indicated with an N.

Note that these indicators are a guide. Rearrangement of sections may not be captured in the markup, but users can view complete revision details in the First and Second Draft Reports located in the archived revision information section at