Vehicle Emissions Testing

California Vehicle Emissions Inspection Laws

The following article will give you the basics of “smog” laws in California. Below you can find out how smog checks are performed in the state of California, and which vehicles can be exempt from the laws.

Emissions (smog) inspections are required for all vehicles registered in the state of California, with vehicles registered in areas subject to the biennial smog certification program required to undergo testing for every other registration renewal.  Vehicles in these areas are exempted for the newest eight registration model years, but are required to pay an annual “smog abatement fee” during those years.

Diesel vehicles model year 1998 and newer or vehicles with a GVWR of 14,000 lbs or less are required to be tested. Gasoline vehicles are exempt if model 1975 or older.


  1. New vehicles for the newest eight (8) model years (must pay an annual “smog abatement” fee)
  2. Pre-1976 model year gasoline vehicles
  3. Pre-1997 model diesel vehicles
  4. Vehicles registered as “specially constructed” that have received an emissions waiver
  5. Motorcycles and electric-powered vehicles

Smog inspections are required in the following counties: Alameda, Butte, Colusa, Contra Costa, Fresno, Glenn, Kern, Kings, Los Angeles, Madera, Marin, Merced, Monterey, Napa, Nevada, Orange, Sacramento, San Benito, San Francisco, San Joaquin, San Luis Obispo, San Mateo, Santa Barbara, Santa Clara, Santa Cruz, Shasta, Solano, Stanislaus, Sutter, Tehama, Tulare, Ventura, Yolo, and Yuba.

The counties of El Dorado, Placer, Riverside, San Bernardino, San Diego, and Sonoma require smog certifications within certain zip codes only.

Please note we only provide this information about vehicle emissions for informational purposes. You should always double-check current official California statutes and regulations to ensure this information is correct.

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This article about California Vehicle Emissions Inspection Laws was last updated in 2021. If any of our information is incomplete or outdated please let us know. Thank you!