Adoption of NEC Standards Across States
| State | NEC in effect as at Mid Sept 2017 | 2017 NEC Adoption | Other Editions Of NEC Adoption Status |
| Alabama | 2016 July 01, (Alabama Division of Construction Management) | Not in process | |
| Alaska | 2014 (2016 March 06) | Not in process | |
| Arizona | Local adoption only | ||
| Arkansas | 2014 (2014 Nov. 21) | Adoption process underway (effective date not established) | |
| California | 2014 (2017 Jan. 01) | Not in process | |
| Colorado | 2017 (2017 June 01) | ||
| Connecticut | 2014 (2016 Oct. 01) | Adoption process underway (effective date not established) | |
| Delaware | 2014 (2016 March 11) | Not in process | |
| Florida | 2011 | 2014 edition (2017 Dec. 31) | |
| Georgia | 2014 (2015 Jan. 01) | Adoption process underway (2018 Jan. 01) | |
| Hawaii | 2014 (2017 March 27) | ||
| Idaho | 2017 (2017 July 01) | ||
| Illinois | 2008 (2011 July 01 – commercial occupancies for areas outside of local jurisdictions that have adoption authority) | Not in process | Not in process |
| Indiana | 2008 | Not in process | Not in process |
| Iowa | 2014 (2015 Jan. 01) | Adoption process underway (tentative effective date of 2018 Jan. 18) | |
| Kansas | 2008 (2011 Feb. 04 – State Fire Marshal) | Not in process | Not in process |
| Kentucky | 2014 (2014 Oct. 01) | Adoption process underway (Effective date not established) | |
| Louisiana | 2011 | 2014 edition (2017 July 01) | |
| Maine | 2014 (2014 Aug. 01) | Adoption process underway (mid-2017) | |
| Maryland | 2014 (2015 Jan. 01) | Not in process | |
| Massachusetts | 2017 w/MA Amendments (2017 Jan. 01) | ||
| Michigan |
2014 Commercial (2015 June 18) Residential (2016 Feb. 08) |
Adoption process underway (effective date not established) | |
| Minnesota | 2017 (2017 July 01) | ||
| Mississippi | Local adoption only | ||
| Missouri | Local adoption only | ||
| Montana | 2014 (2014 Oct. 23) | Not in process | |
| Nebraska | 2017 (2017 Aug. 01) | ||
| Nevada | 2011 (2013 July 01 – Nevada State Pubic Works Division) | Not in process | Not in process |
| New Hampshire | 2014 (2015 Jan. 01) | Adoption process underway (2018 Jan. 01) | |
| New Jersey | 2014 (2015 Sep. 21 with 6 month grace period for new permits) | Not in process | |
| New Mexico | 2014 (2014 Aug. 01) | Adoption process underway (Effective date not established) | |
| New York | 2014 (2016 April 06 with 6-month grace period ending 2016 Oct. 03) | Not in process | |
| North Carolina | 2014 (2016 April 01) | Adoption process underway (2018 April 01) | |
| North Dakota | 2017 (2017 July 01) | ||
| Ohio |
2014 Commercial (2015 Jan. 01) Residential (2016 Jan. 01) |
2017 Nov. 01 Commercial | |
| Oklahoma |
2014 Commercial (2015 Nov. 01) Residential 2015 IRC Electrical Chapters (2016 Nov. 01) |
Not in process | |
| Oregon | 2014 (2014 Oct. 01) | Adoption process underway (2017 Oct. 01) | |
| Pennsylvania | 2008 | Not in process | Not in process |
| Rhode Island | 2014 (2014 July 01) | Adoption process underway (effective date not established) | |
| South Carolina | 2014 (2016 July 01) | Not in process | |
| South Dakota | 2017 (2017 July 01) | ||
| Tennessee | 2008 | 2011 edition (effective date not established) | |
| Texas | 2017 (2017 Sep. 01) | ||
| Utah | 2014 (2016 July 01) | Adoption process underway (effective date not established) | |
| Vermont | 2014 (2017 Oct. 01) | Adoption process underway (2017 Oct. 01) | |
| Virginia | 2011 (2014 July 14) | 2014 edition (2018 March) | |
| Washington | 2017 (2017 July 01) | ||
| West Virginia | 2014 (2016 Aug. 01) | Not in process | |
| Wisconsin | 2011 | Adoption process underway (effective date not established) | |
| Wyoming | 2017 (2017 July 01) | ||
| New York City | 2008 w/NYC amendments (2011 July 01) | 2014 (effective date not established |