Vehicles Subject to Smog Check
When is a Smog Check required?
A Smog Check is required every other year (biennially) as part of the vehicle registration process. The Department of Motor Vehicles (DMV) registration renewal notice will indicate if a Smog Check is required. A Smog Check is also required when a vehicle changes ownership or when it is registered for the first time in California.
Check a vehicle's Smog Check history by VIN or license plate number using our online feature.
What vehicles require a Smog Check?
Gasoline-powered vehicles, hybrid vehicles, and alternative-fuel vehicles that are model-year 1976 and newer require a Smog Check, with the following exceptions:
- Eight model years and newer do not require a biennial Smog Check.
- Four model years and newer do not require a change-of-ownership Smog Check.
To determine the first year a vehicle requires a biennial or change-of-ownership Smog Check, add eight or four, respectively, to the model year of a vehicle.
For example, a 2020 model-year vehicle will first be subject to a biennial Smog Check in 2028 (2020 + 8 = 2028). That same vehicle will require a change-of-ownership Smog Check if sold in or after 2024 (2020 + 4 = 2024).
Diesel-powered vehicles that are model-year 1998 and newer with a gross vehicle weight rating of 14,000 pounds and less require a Smog Check. There are no model year exceptions for diesel-powered vehicles.
What vehicles do not require a Smog Check?
- Gasoline-powered vehicles, hybrid vehicles, and alternative-fuel vehicles that are model-year 1975 and older.
- Gasoline-powered vehicles, hybrid vehicles, and alternative-fuel vehicles that are eight model years and newer do not require a biennial Smog Check.
- Gasoline-powered vehicles, hybrid vehicles, and alternative-fuel vehicles that are four model years and newer do not require a change-of-ownership Smog Check.
- Diesel-powered vehicles that are model-year 1997 and older.
- Diesel-powered vehicles with a gross vehicle weight rating of more than 14,000 pounds.
- Electric-powered vehicles.
- Motorcycles.
If I sell my vehicle, who is responsible for the change-of-ownership Smog Check?
Under California law, the seller is responsible for having a Smog Check performed on the vehicle and providing the buyer the certificate of compliance.
My 1976 model-year vehicle was built in 1975. Does it require a Smog Check?
Yes. Smog Check requirements are based on vehicle type and model year, not the date of manufacture.
My vehicle is eight years old. Why does it require a Smog Check?
Smog Check requirements are based on vehicle type and model year. Model years are released in the calendar year prior to a vehicle’s model year. Thus, a vehicle is one model year old when the model year matches the calendar year. For example, a 2010 model-year vehicle is one model year old in 2010 and nine model years old in 2018. Accordingly, a 2010 model-year vehicle requires its first biennial Smog Check in 2018.
Do collector cars require a Smog Check?
Collector cars that are model-year 1976 and newer require a Smog Check. Because Smog Check stations do not have the equipment necessary to inspect collector cars, collector cars are eligible for an abbreviated inspection performed by a Smog Check Referee. For more information, visit our Collector Car page or asktheref.org.
All vehicles that are model-year 1975 and older do not require a Smog Check.
Do RVs/motor homes require a Smog Check?
Yes, RVs/motor homes require a Smog Check. Requirements are based on vehicle type and model year.
Do government-owned vehicles require a Smog Check?
Yes, passenger vehicles or light-duty trucks owned or leased by federal, state, county, city, and special district agencies require a Smog Check.
Is the Smog Check Program biased against older vehicles?
No. While California law requires the Smog Check Program to focus on high-polluting vehicles, the Smog Check Program also does not require older vehicles to meet the same emissions standards as newer vehicles. Smog Check emissions standards consider the vehicle type and model year so that a vehicle is never held to a standard that applied when the vehicle was originally manufactured.
