How do tamper-resistant outlets work?

Spring-loaded shutters behind both slots only open when equal simultaneous pressure is applied to both sides, as when inserting a standard two-prong or three-prong plug.

Can I replace a standard outlet with a tamper-resistant one myself?

A homeowner comfortable with basic wiring can make the swap since it is a direct replacement. The circuit should be de-energized and tested before starting work.

Do tamper-resistant outlets make it harder to plug things in?

There may be slightly more resistance when inserting a plug, but it is minimal with a properly aligned two-prong or three-prong plug. The difference is barely noticeable in daily use.

Are tamper-resistant outlets the same as childproof outlet covers?

No, plastic outlet covers are separate accessories that can be removed. Tamper-resistant outlets have built-in shutters that are a permanent part of the receptacle and cannot be removed by a child.

Tamper-Resistant Outlet — TR Receptacle Code and Safety

Q: Are tamper-resistant outlets required by code?

Yes, the NEC requires tamper-resistant receptacles in all 125-volt 15-amp and 20-amp outlets in new dwelling unit construction, with few exceptions.

A tamper-resistant outlet is an electrical receptacle with built-in spring-loaded shutters that block foreign objects from being inserted into the contact slots.

Tamper-Resistant Outlet diagram — labeled parts and installation context

What It Is

A tamper-resistant outlet, often abbreviated TR, uses internal spring-loaded shutters behind both vertical slots that only open when equal pressure is applied to both sides simultaneously, as happens when inserting a standard two-prong or three-prong plug. A single object like a key, hairpin, or small finger pushing on one slot alone cannot open the shutters because the mechanism requires opposing force on both sides to release.

The NEC has required tamper-resistant receptacles in all 125-volt, 15-amp and 20-amp outlets in new dwelling-unit construction since the 2008 code cycle (NEC 406.12). This requirement was introduced after CPSC data showed approximately 2,400 children per year suffering shock and burn injuries from inserting objects into unprotected receptacle slots. The TR mechanism is entirely internal and permanent, requiring no action from the homeowner to maintain protection.

Types

Standard 15-amp and 20-amp duplex receptacles with TR shutters are the most common type, available in both traditional and decorator-style (flat faceplate) form factors. The 20-amp version has one T-shaped slot to accept both 15-amp and 20-amp plugs. GFCI receptacles with tamper resistance combine ground-fault protection with the shutter mechanism in a single device, satisfying two code requirements at once.

Weather-resistant tamper-resistant (WR-TR) outlets are rated for damp and wet locations and carry both the TR and WR markings. They use corrosion-resistant internal components and are required for outdoor receptacles and certain indoor damp locations. Hospital-grade TR receptacles have heavier contact springs and a more robust housing, and they are identified by a green dot on the face.

Where It Is Used

Tamper-resistant outlets are required in all dwelling-unit locations in new construction, including bedrooms, living rooms, kitchens, bathrooms, hallways, garages, basements, and laundry rooms. The NEC requirement applies to every receptacle outlet in the dwelling unit with very limited exceptions, such as receptacles located more than 5.5 feet above the floor or those behind dedicated appliances that are not readily accessible.

Beyond dwelling units, TR receptacles are also required in childcare facilities, schools, hotel guest rooms, dormitories, and any occupancy where child safety is a concern. Many jurisdictions have adopted the NEC requirement without amendment, making TR outlets the default for virtually all new residential electrical work.

How to Identify One

Look for the letters "TR" stamped or molded into the face of the receptacle between or near the slots. On decorator-style outlets, the marking may appear on the side or bottom of the faceplate opening. The shutters are visible as small white or tan plastic barriers behind each slot that move only when both are pressed at the same time with a plug.

When comparing a TR outlet to a standard outlet side by side, the shutter mechanism is the only visible difference. The TR receptacle has the same dimensions, mounts in the same standard single-gang or multi-gang wall box, and accepts the same wall plates. Weather-resistant versions carry an additional "WR" marking alongside the TR stamp.

Replacement

Replacement is needed when the shutters stick or fail to open reliably with a standard plug, when the receptacle body is cracked or heat-damaged, or when an older non-TR outlet is being upgraded to meet current code during a renovation. TR receptacles are a direct swap for standard outlets, using the same 14 AWG or 12 AWG branch circuit wiring and the same screw-terminal or back-wire connections.

When upgrading an entire house from non-TR to TR outlets, the work is straightforward but requires de-energizing each circuit and testing with a voltage tester before handling any wiring. In kitchens, bathrooms, garages, and outdoor locations, the replacement should be a WR-TR GFCI receptacle or a standard TR receptacle fed from an upstream GFCI to satisfy both tamper-resistance and ground-fault protection requirements.