Anti-lock brakes are required by law on new passenger cars, light trucks, SUVs, and most commercial vehicles over 10,000 pounds gross vehicle weight rating, but the requirement reached each category through a different federal rule and on a different date. Motorcycles are the exception: no federal rule requires ABS on new bikes sold in the United States. Vehicles built before the applicable mandate are not required to be retrofitted.
New Cars, SUVs, and Light Trucks
No federal regulation directly requires ABS as standalone equipment on passenger cars. Federal Motor Vehicle Safety Standard 135 sets performance requirements for light-vehicle brake systems that have ABS, but it does not mandate installation.1eCFR. 49 CFR 571.135 – Standard No. 135; Light Vehicle Brake Systems What made ABS effectively universal on new cars is the electronic stability control mandate in FMVSS 126. ESC physically relies on ABS hardware to selectively brake individual wheels, so requiring ESC requires ABS by extension.
FMVSS 126 phased in ESC for passenger cars, SUVs, and light trucks up to 10,000 pounds GVWR on this schedule:
- September 1, 2008: at least 55 percent of a manufacturer’s production.
- September 1, 2009: at least 75 percent.
- September 1, 2010: at least 95 percent.
- September 1, 2011: 100 percent of all new light vehicles.
Final-stage manufacturers and vehicle alterers had until September 1, 2012, to comply.2eCFR. 49 CFR 571.126 – Standard No. 126; Electronic Stability Control Systems for Light Vehicles Any new car or light truck sold today will have both ABS and ESC.
Commercial Trucks, Buses, and Trailers
Heavy vehicles were required to have ABS years before passenger cars, under two standards that split by brake type.
Air Brakes
FMVSS 121 governs air brake systems on heavy vehicles. ABS became mandatory on the following dates:3eCFR. 49 CFR 571.121 – Standard No. 121; Air Brake Systems
- March 1, 1997: new air-braked truck tractors with a GVWR over 10,000 pounds.
- March 1, 1998: all other new air-braked trucks, buses, and trailers over 10,000 pounds GVWR.
These vehicles must also carry functioning ABS malfunction indicators that alert the driver to a problem.4eCFR. 49 CFR 393.55 – Antilock Brake Systems
Hydraulic Brakes
Heavy trucks with hydraulic brakes fall under FMVSS 105, which requires ABS on hydraulic-braked trucks and buses over 10,000 pounds GVWR, controlling at least one front axle and one rear axle. The requirement applies to vehicles manufactured on or after March 1, 1999, and those vehicles must also have ABS malfunction indicators.5eCFR. 49 CFR 571.105 – Standard No. 105; Hydraulic and Electric Brake Systems
Motorcycles
Federal law does not require ABS on motorcycles sold in the United States. The NTSB has recommended that NHTSA require ABS on all new on-road motorcycles, and IIHS and HLDI have filed two petitions seeking the same, most recently in November 2023, but NHTSA has not initiated rulemaking.6Insurance Institute for Highway Safety. IIHS-HLDI Petition for Rulemaking on Motorcycle ABS Manufacturers have moved ahead of regulators: as of model year 2020, ABS was standard or optional on at least 70 percent of new motorcycle models sold in the U.S., with over 60 percent offering it as standard equipment.7National Highway Traffic Safety Administration. NHTSA Response to NTSB Safety Recommendation H-18-32
Older Vehicles
Federal safety standards apply to new vehicles at the time of manufacture and are not retroactive. A car built in 2005 without ESC, or a truck built in 1995 without ABS, does not need a retrofit to remain street-legal. The mandate dates mark when manufacturers had to start building the equipment into new vehicles.
Disabling ABS
Federal law prohibits manufacturers, dealers, distributors, rental companies, and motor vehicle repair businesses from knowingly disabling any safety device installed to comply with a federal safety standard.8Office of the Law Revision Counsel. 49 USC 30122 – Making Safety Devices and Elements Inoperative A shop cannot legally disconnect ABS on a vehicle that was required to have it when built.
The statute does not explicitly reach individual owners working on their own vehicles, but other rules constrain what you can do. Commercial vehicles must maintain functioning ABS and malfunction indicators under 49 CFR 393.55, and drivers operating a commercial vehicle with disabled ABS face federal enforcement.4eCFR. 49 CFR 393.55 – Antilock Brake Systems FMVSS 135 also prohibits any control that lets the driver manually disable ABS on a light vehicle equipped with the system.1eCFR. 49 CFR 571.135 – Standard No. 135; Light Vehicle Brake Systems Some states require functioning ABS to pass periodic safety inspection, though the rules vary by state, and an illuminated ABS warning light can trigger a failure in stricter jurisdictions.