NM cable · 2026 NEC
Securement and support
Support and secure NM cable at intervals no greater than 4½ ft, within 12 in. of every cable entry into an enclosure, and with no more than 18 in. of cable between the entry and the nearest support.
- Use cable ties listed and identified for cable support, listed staples, straps, hangers, or similar fittings designed and installed without damaging the cable.
- Flat cable must not be stapled on edge. A section protected from physical damage by a raceway does not need separate securement inside that raceway.
NEC references: 334.30
NM cable · 2026 NEC
Horizontal runs through framing holes or notches
A horizontal NM run through holes or notches that comply with 300.4 is considered supported when intervals do not exceed 4½ ft and cable is secured within 12 in. of each box, cabinet, conduit body, or other NM cable termination.
- This allowance applies to horizontal runs; it does not make a vertical run supported by holes alone.
- Hole and notch dimensions, structural limits, and protection from fasteners are separate checks under 300.4.
NEC references: 334.30(A), 300.4
NM cable · 2026 NEC
Cable fished through a finished space
NM cable may be left unsupported and unsecured only when it is fished between access points through concealed spaces in a finished building or structure and securing/supporting it is impracticable.
- This is a limited exception for a fished concealed run. It does not apply merely because the cable route is difficult or hidden.
- Protect the cable at access points and where it could be damaged by fasteners or other work.
NEC references: 334.30(B)(1), 300.4
NM cable · 2026 NEC
Accessible ceiling connection
The unsupported length may be up to 4½ ft from the last support to a luminaire or other equipment connection when both the cable and connection are in an accessible ceiling in a one-, two-, or multifamily dwelling.
- Check the ceiling access and dwelling conditions before relying on this allowance. It is not a general 4½ ft slack rule for concealed walls.
NEC references: 334.30(B)(2)
NM cable · 2026 NEC
NM cable passing through a floor
Where NM cable passes through a floor, enclose and protect it with an approved raceway or other approved means extending at least 6 in. above the floor.
- The code lists rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC conduit, RTRC marked -XW, or other approved means.
- Protect the cable from abrasion at raceway entries and exits with an appropriate bushing or adapter.
NEC references: 334.15(B)
NM cable · 2026 NEC
NM cable crossing joists in unfinished spaces
Where a run crosses joists in an unfinished basement or crawl space, direct attachment to the lower joist edges is limited to cable containing at least two 6 AWG conductors or three 8 AWG conductors.
- Smaller cable must pass through bored joist holes or run on a suitable running board; do not apply the direct-attachment allowance to every cable size.
- Check bored-hole setbacks, fastener protection, and structural limits separately before drilling or notching framing.
NEC references: 334.15(C), 300.4
NM cable · 2026 NEC
NM cable on an unfinished basement wall
On an unfinished basement wall, Type NM cable may be installed in conduit or tubing listed for the application, with wiring protection provided as required by the adopted code.
- Protect cable from abrasion at raceway entries and exits.
- Extend the cable sheath at least 1/4 in. into the box and secure the cable within 12 in. of the point where it enters the raceway.
- Check grounding and bonding requirements for metal raceways, fittings, and boxes separately.
NEC references: 334.15(C), 300.4
NM cable · 2026 NEC
Bored holes through wood framing
Keep the edge of a bored hole at least 1¼ in. from the nearest edge of the wood member. If that clearance cannot be maintained, protect wiring from screws or nails with a steel plate or bushing at least 1⁄16 in. thick, sized to cover the wiring.
- The measurement is from the edge of the bored hole to the nearest edge of the wood member, not from the cable centerline.
- Use an approved listed plate thinner than 1⁄16 in. only when it is marked as providing equal or better protection.
NEC references: 300.4
NM cable · 2026 NEC
Notches in wood framing
Notches may be used only where they do not weaken the structure; protect the wiring at the notch from screws or nails with a steel plate at least 1⁄16 in. thick and install the plate before applying the finish.
- Structural notching limits are outside this electrical reference. Follow the applicable building requirements and approved plans.
NEC references: 300.4
NM cable · 2026 NEC
Cable parallel to framing or furring
Where nails or screws are likely to penetrate, keep the nearest outside surface of the cable at least 1¼ in. from the nearest framing or furring edge; otherwise provide a steel plate, sleeve, or equivalent protection at least 1⁄16 in. thick.
- This clearance is measured from the outside surface of the cable to the nearest framing edge. Check the full 300.4 rule and its exceptions.
NEC references: 300.4
NM cable · 2026 NEC
Cable through metal framing
Protect NM cable passing through punched, cut, or drilled openings in metal framing with listed bushings or grommets that cover all metal edges and are fastened in the opening before the cable is installed.
- Check the framing manufacturer’s instructions and all applicable physical-damage protection requirements.
NEC references: 300.4
NM cable · 2026 NEC
Wiring device listed without a separate outlet box
A device identified for use without a separate box and with an integral cable clamp may be installed when NM cable is secured at intervals no greater than 4½ ft and within 12 in. of the wall opening.
- Leave at least a 12 in. loop of unbroken cable or a 6 in. cable end on the interior side of the finished wall so the device can be replaced.
- Use only a device identified and listed for this installation method. This does not permit removing an outlet box from an ordinary device.
NEC references: 334.30(C)
NM cable · 2026 NEC
Exposed cable and physical-damage risk
Protect NM cable from physical damage where necessary. The required protection depends on the location, exposure, and installation method; this reference does not assign one universal height or raceway for every exposed run.
- Where NM cable passes through a floor, use the specific floor-passage protection rule listed separately.
- In unfinished basements, crawl spaces, garages, and utility areas, evaluate likely impact, storage, access, and fastening hazards. Confirm the approved protection method with the authority having jurisdiction.
NEC references: 334.15(B), 300.4
