300.15 Boxes and fittings required
What changed in 300.15
An identified fitting used where a box or conduit body would otherwise go can now be concealed, as long as it is listed for concealment.
Point by point
- Still true: a box or conduit body is needed wherever conductors are spliced, terminated, pulled or switched, unless an exception applies.
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- 2 more points on exactly what changed
- The 2017 rule next to the 2020 rule, side by side
- Why it changed
- What to do and check on the job
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This section across NEC® editions
2020 NEC®RevisedYou're here
An identified fitting used where a box or conduit body would otherwise go can now be concealed, as long as it is listed for concealment.
2023 NEC®Revised
A box, conduit body or approved fitting is now also required at any point where you switch wiring methods.
Open the 2023 page →2026 NEC®Revised
Found at 300.17 in the 2026 NEC®.
Renumbered from 300.15. The wording that lets a fitting take the place of a box was clarified.
Open the 2026 page →More 2020 changes in Article 300
This is a plain-English summary, not the NEC®'s exact wording. Always check the full section in the NEC® edition your area has adopted, plus any local amendments.
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