Best for: Leviton panel owners going smart gradually
Standout: Remote on/off and per-circuit energy for about $90
Watch out: Needs the LWHEM hub and a Leviton panel
Not for: Square D, Eaton, Siemens or other panels
The Leviton LB120-ST is a 2nd Gen 1-pole, 20A smart circuit breaker. In a Leviton load center with the LWHEM hub, it lets you switch a circuit on or off from your phone, set schedules and see its energy use. It costs about $85 to $100.
What you need before you buy
A Leviton load center. It will not fit other brands.
The LWHEM Whole Home Energy Monitor hub to connect to the app.
An electrician to swap breakers in the panel.
What you can do with it
Turn off a garage or guest-room circuit remotely, schedule circuits to shut off overnight, and see which circuits use the most power. Add more breakers later as budget allows.
How I researched this: Leviton’s 2nd Gen smart breaker product page and specs, the Amazon listing, and Leviton’s smart breaker video. Prices checked October 30, 2026.
Leviton 2nd Gen Smart Circuit Breaker (LB120-ST)
Leviton's 2nd Gen smart breaker adds remote control and per-circuit energy data to a Leviton panel for about $90. Here is what you need first.
Product Brand:
Leviton
Editor's Rating: 4.5
Pros
Turn a circuit on or off from your phone and set schedules
Shows energy use per circuit in the My Leviton app
Lets you make a Leviton panel smart one circuit at a time
About $90 per breaker, far cheaper than replacing the panel
Works with the same app as Leviton EV chargers and switches
Cons
Only fits Leviton load centers
Needs the Leviton LWHEM Whole Home Energy Monitor hub to work
Standard 1-pole 20A only; AFCI, GFCI and 2-pole versions are separate models
Must be installed by an electrician
Specs
Model
LB120-ST (2nd Gen)
Type
Standard 1-pole smart circuit breaker
Rating
20A, 120V, 10kA interrupt rating
Requires
Leviton Load Center and LWHEM Whole Home Energy Monitor hub
App
My Leviton (remote on/off, schedules, per-circuit energy)
Install
Licensed electrician
Weight
6.7 oz
Verdict
If you already have a Leviton panel, these breakers are the cheapest way to add per-circuit control and energy data, a few at a time. They do nothing in other brands' panels; for a full smart panel, see the Leviton Smart Load Center or SPAN.
