California requires a smog check every two years for most vehicles, with some exceptions based on age and type

Your smog check schedule depends on when your vehicle was registered and what you drive. Most vehicles registered in California need a smog check every 24 months. However, vehicles registered before 1975, diesel vehicles registered before 1998, and gasoline vehicles registered before 1981 are exempt. If you drive a vehicle registered after those cutoff years, you will need to get checked on a regular cycle tied to your registration renewal date.

The state ties your smog check to your registration expiration date, not to a calendar. When your registration is about to expire, you must pass a smog check before you can renew it. If your registration expires on June 15, your smog check must be completed no more than 90 days before that date. You cannot renew your registration without proof of a passing smog check (with rare exceptions for new vehicles and those meeting other specific criteria).

Key Takeaways

  • Most California vehicles need a smog check every two years, timed to your registration renewal date.
  • Vehicles older than 1975 (gasoline), 1981 (gasoline), or 1998 (diesel) do not require smog checks.
  • You can get a smog check up to 90 days before your registration expires, but not after.
  • You must show proof of a passing smog check when you renew your registration with the Department of Motor Vehicles.
  • If your vehicle fails, you have until your registration expires to fix it and pass a retest.

When your registration expires determines your smog check due date

The California Department of Motor Vehicles (DMV) assigns your registration expiration date when you first register your vehicle. This date appears on your registration card and renewal notice. Your smog check window opens 90 days before that expiration date and closes on the expiration date itself.

For example, if your registration expires on September 30, you can get a smog check starting July 1. You must complete it by September 30. If you wait until October 1 to get checked, you will not be able to renew your registration until you pass a smog check, and you will be driving with expired registration.

The DMV sends you a renewal notice about 60 days before your registration expires. This notice includes your expiration date and reminds you that a smog check is required. Keep this notice or check your registration card to know your important date.

Vehicles that do not need smog checks

California exempts older vehicles from smog check requirements because they were built before modern emissions standards. Gasoline-powered vehicles registered before January 1, 1981 do not need smog checks. Diesel vehicles registered before January 1, 1998 are also exempt. Any vehicle registered before January 1, 1975 is exempt regardless of fuel type.

New vehicles (typically those with a model year within the current or previous two years) may be exempt for their first few years of registration, depending on when they were registered. Vehicles registered as new with the manufacturer's original title usually have a grace period. Check your renewal notice or contact the DMV to confirm whether your newer vehicle is exempt.

Electric vehicles and hydrogen fuel cell vehicles are exempt from smog checks because they produce no tailpipe emissions. If you own one of these vehicles, you do not need a smog check to renew your registration.

What happens if your vehicle fails the smog check

If your vehicle fails a smog check, you receive a written report detailing which emissions standards it did not meet. You have until your registration expiration date to repair the vehicle and pass a retest at any certified smog station. The retest costs money (fees vary by station), but you do not pay for the initial failed test again.

If you cannot afford repairs before your registration expires, you can request a Smog Check Abatement from the DMV. This allows you to renew your registration even with a failed smog check, but only if you meet specific income requirements and your vehicle is at least 16 years old. You must still repair the vehicle within a set timeframe or face penalties.

Some repairs are covered under California's Consumer information Program (CAP) if your vehicle fails and the repair cost exceeds a certain threshold (the limit changes yearly). CAP can help pay for emissions-related repairs on vehicles that meet income and age requirements. Contact your local air quality management district to learn whether your situation qualifies.

Where to get a smog check in California

You can get a smog check at any Bureau of Automotive Repair (BAR) certified smog station. These are private businesses — gas stations, repair shops, and dedicated smog-check facilities — that have passed state inspection and use approved equipment. The BAR maintains a searchable database of certified stations on its website where you can find locations near you.

Smog check fees are not set by the state; each station sets its own price. Typical costs range from $30 to $70 for a basic smog check, though prices vary by location and vehicle type. Some stations charge more for trucks or vehicles with special equipment. Call ahead to ask the price before you go.

You will need your vehicle registration card and proof of ownership (such as your title or registration) when you arrive. Bring your keys so the technician can start the vehicle and run the test. The entire process usually takes 15 to 30 minutes.

Smog check requirements for different vehicle types

Most passenger cars, SUVs, and light trucks follow the standard two-year smog check schedule. Heavy-duty diesel trucks, commercial vehicles, and vehicles over a certain weight may have different requirements or may be exempt. Check your renewal notice or the BAR website to confirm the rules for your specific vehicle type.

Motorcycles and motorized bicycles have their own emissions rules and may not require a smog check at all, depending on engine size and year. Trailers and vehicles registered as non-operational do not need smog checks. If you are unsure whether your vehicle type requires a check, contact the DMV or your local air quality management district.

Frequently Asked Questions

Can I get a smog check more than 90 days before my registration expires?

No. A smog check is only valid if completed within 90 days of your registration expiration date. If you get one earlier, it will not count toward your renewal. You can check your registration card or renewal notice to see your expiration date and plan accordingly.

What if I move to another state — do I still need a California smog check?

If your vehicle is registered in California, you need a smog check to renew that registration, even if you move out of state. If you transfer your registration to another state, you no longer need California smog checks. Contact the DMV about out-of-state moves and registration transfers.

Do I need a smog check if I only drive my car occasionally?

Yes. The requirement is based on your registration renewal date, not how often you drive. If your registration is expiring, you must pass a smog check before you can renew it, regardless of mileage or usage.

How long does a smog check result stay valid?

A passing smog check is valid for 30 days from the test date. You must complete your registration renewal within that 30-day window. If your registration does not renew within 30 days of the test, you will need another smog check to complete the renewal.

What if I cannot find a certified smog station near me?

The BAR website has a searchable database of all certified stations in California. If no stations are listed in your when ready area, expand your search radius — many people drive to a nearby town to get checked. You can also call your local air quality management district for recommendations.