Is Air Suspension Legal in the US?

Conditional

Air suspension is legal in the US as long as, at the height you actually drive, the car meets your state's minimum ride-height rules and keeps its headlights legal. Dropping it to the ground to drive is where it crosses the line.

Why?

Adjustable air ride is legal to install; the law cares about the height you drive at, not the ability to go lower. At road-going height, the car must clear your state's minimum bumper or frame height and keep the headlights at a legal height and aim.

Because the height is adjustable, the practical rule is simple: air it up to a legal, safe ride height to drive, and save the slammed look for shows on private property. The system also has to hold its height reliably and be securely mounted.

So air suspension is road-legal when driven at a compliant height; used to run illegally low on the street it is not. As with any major suspension change, tell your insurer.

What decides if it's legal

At driving height the car must meet the state’s minimum ride height.
Headlights must stay at a legal height and aim while driving.
The system must be safe and hold its set height reliably.
Running slammed on the road is where it becomes illegal.

Does it depend on your state?

Yes. The minimum driving height is set by state law, so how low you can legally drive depends on your state. The ability to lift and lower is legal everywhere; running slammed on the road is not.

Related legality guides

Find your car in the garage

Sources

This page is general guidance, not legal advice, on the rules in the US for air suspension. The detail varies by exact vehicle and changes over time - confirm with your insurer and the EPA, NHTSA and your state DMV before modifying.