What Changed in NEC 2023
NEC 2023 (NFPA 70) major changes: GFCI/AFCI expansion, EV charging Article 625, Article 712 DC microgrids, surge protection 230.67
NEC 2023 (NFPA 70) is the 2023 edition of the National Electrical Code, published by NFPA in August 2022 and progressively adopted by state and municipal jurisdictions through 2024-2026. The 2023 cycle is one of the most consequential in recent decades because of major additions for electric vehicles, energy management, and DC microgrid systems, plus aggressive expansion of GFCI and AFCI protection. Here is the high-level change map.
New Articles in NEC 2023
| Article | Title | Scope |
|---|---|---|
| 235 | Branch Circuits, Feeders, and Services Over 1000V AC, 1500V DC | Consolidated medium/high voltage rules |
| 245 | Overcurrent Protection for Systems Rated Over 1000V AC, 1500V DC | Companion to 235 |
| 305 | General Requirements for Wiring Methods and Materials for Systems Rated Over 1000V AC, 1500V DC | Wiring above 1000V |
| 369 | Insulated Bus Pipe (IBP) / Tubular Covered Conductors (TCC) | New raceway type |
| 712 | Direct Current Microgrids | DC distribution and load systems |
| 726 | Class 4 Fault-Managed Power Systems | New class of low-voltage controlled-energy circuits |
The DC Microgrid Article 712 is especially significant: it provides the first dedicated framework for building-scale DC distribution at voltages above the historical extra-low-voltage limits.
GFCI Expansion - NEC 210.8
NEC 2023 substantially expanded GFCI protection:
- 210.8(A) dwelling-unit GFCI now covers all 125V to 250V receptacles in kitchens (previously 125V only), garages, accessory buildings, outdoors, crawl spaces, basements, bathrooms, laundry areas, near sinks, and indoor damp/wet locations
- 210.8(B) non-dwelling GFCI added similar 125V-250V coverage for commercial kitchens, garages, sinks, and rooftops
- 210.8(D) specific appliances - dishwasher, electric ranges, electric ovens, microwave, garbage disposers (when required by 422.5) - now require GFCI protection
- 210.8(F) outdoor outlets for dwelling units expanded to include the entire outdoor space and not just specific receptacles
AFCI Expansion - NEC 210.12
- 210.12(A) dwelling-unit AFCI continues to cover most 15A and 20A 120V branch circuits supplying outlets and devices in dwelling-unit rooms
- 210.12(D) added AFCI requirement when extending or modifying existing branch circuits in protected spaces
EV Charging - Article 625
Article 625 received major rewrites in NEC 2023 for EV supply equipment (EVSE):
- 625.40 dedicated circuit requirement clarified
- 625.41 overcurrent protection sizing aligned to continuous-load 125% factor
- 625.42 rating and disconnecting means rules updated for Level 2 and DC fast chargers
- 625.48 interactive systems and bidirectional charging (V2X, V2H) framework added
- 625.60 energy management systems integration with EVSE
Surge Protection - NEC 230.67
NEC 2020 introduced mandatory surge protective devices (SPDs) for dwelling-unit services. NEC 2023 extended this in 230.67(A)/(B):
- All dwelling-unit services now require an integral or external Type 1 or Type 2 SPD
- Required at the service equipment or the next level of distribution
- Replacement of service equipment triggers SPD installation per 230.67(D)
Energy Management Systems - Article 750
Article 750 covers Energy Management Systems (EMS) - load shedding, load monitoring, and demand control hardware:
- 750.20 control of loads as part of an overall energy strategy
- 750.30 monitoring and metering integration
This article makes formal what whole-home load management hardware was already doing in the field for EV charger load balancing.
Working Space - NEC 110.26
NEC 110.26 working space rules received targeted updates:
- 110.26(A)(4) limit of equipment access requirements clarified for >30A 1000V equipment
- 110.26(C)(2) entrance to and egress from large enclosures expanded
Service Conductor Sizing - NEC 310.12 Dwelling Services
Table 310.12(B) for single-phase dwelling services was updated for clarity in the 2023 cycle, but the underlying values for typical 100A/200A/400A services in 4/0 AL / 2/0 Cu / 250 kcmil AL remain consistent with NEC 2020.
Receptacle Tamper Resistance - NEC 406.12
NEC 2023 extended tamper-resistant (TR) receptacle requirements to additional occupancies including childcare, preschool, and waiting rooms in healthcare facilities. Dwelling-unit TR coverage remains comprehensive.
What Did Not Change Materially
For our domain - conduit fill - the answer is reassuring:
- Chapter 9 Tables 1, 4, 5 are materially unchanged from NEC 2020
- Annex C pre-computed counts unchanged for standard insulations
- 310.15(C)(1) ampacity adjustment factors unchanged
- Table 310.16 ampacity values unchanged
See our NEC 2023 vs 2020 conduit fill guide for the table-by-table verification.
Adoption Status as of 2026
State NEC adoption varies. Notable laggards as of mid-2026 include several states still on NEC 2020 or 2017 cycles. Always check your local AHJ before applying NEC 2023 rules - especially the new GFCI/AFCI expansion and the SPD requirement.
How WireFillChart Tracks NEC 2023
Our conduit fill calculator uses the NEC 2023 Chapter 9 dataset, which matches NEC 2020 and NEC 2017 for conduit fill purposes. The ampacity reference reflects NEC 2023 Table 310.16. State-specific adoption notes appear in the state directory pages.