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

Your vehicle needs a smog check every two years in California, unless your car is brand new, very old, or falls into a category that is exempt. The exact timing depends on when you last passed one and what kind of vehicle you own. Most passenger cars registered in California follow the two-year cycle, but diesel vehicles, motorcycles, and vehicles made before 1975 have different rules.

The smog check is tied to your vehicle registration renewal. When your registration is due, your smog check must be current — meaning it was passed within the two years before you renew. If your registration expires in March, your smog check must have been completed no earlier than March of the previous year.

Key Takeaways

  • Most California vehicles need a smog check every two years, timed to your registration renewal date.
  • Vehicles made in 1975 or earlier, electric vehicles, and some motorcycles are exempt from smog checks entirely.
  • You can take your smog check up to 90 days before your registration expires, so you do not have to wait until the last moment.
  • If you fail a smog check, you have 30 days to repair your vehicle and retest at no additional charge.

Which vehicles are exempt from smog checks

Not every vehicle on California roads needs a smog check. Electric vehicles, including plug-in hybrids, are permanently exempt because they produce no tailpipe emissions. Vehicles manufactured before 1975 are also exempt, as are motorcycles and motorized bicycles. Diesel-powered vehicles have their own separate smog check program with different standards.

If you own a vehicle that is fewer than four model years old, you are exempt for those first four years. After that, you enter the regular two-year cycle. For example, a 2024 vehicle registered in 2024 would not need a smog check until 2028. Once that first check is due, you follow the standard two-year schedule from then on.

When to schedule your smog check

You can take your smog check up to 90 days before your registration expires. This gives you a three-month window to find a test station and complete the inspection without rushing. Many people schedule their smog check about a month before their registration renewal date, which leaves time to address any failures.

The smog check itself takes about 10 to 30 minutes at a test station. You do not need an appointment at most locations — you can walk in during business hours. Test stations are certified by the California Bureau of Automotive Repair and are listed on the official smog check website, where you can search by zip code or city.

What happens if you fail your smog check

If your vehicle fails the smog check, you have 30 days to repair it and retest at no additional charge. The test station will give you a written report showing which emissions standards your vehicle did not meet. You then take your vehicle to a repair shop, have the necessary work done, and return to the same test station for a free retest.

If you fail a second time, you can pursue a Gross Polluter Abatement Program waiver, which allows you to register your vehicle even if it does not pass. This requires documented repair attempts and costs, but it is an option if repairs are too expensive. You would need to contact your local air quality management district to learn about waiver programs in your area.

Smog check requirements for diesel vehicles

Diesel vehicles follow a separate smog check program with different emission standards. Most diesel vehicles registered in California need a smog check every two years, just like gasoline vehicles, but the test measures different pollutants. Diesel vehicles made before 1998 may have different requirements or exemptions depending on their weight and registration type.

If you own a diesel vehicle, confirm the specific requirements with a certified smog test station or the California Bureau of Automotive Repair website. Diesel smog checks are less common than gasoline checks, so not every test station performs them — you may need to search for a station that specializes in diesel testing.

How to renew your registration after passing smog check

Once you pass your smog check, the test station uploads the results to the California Department of Motor Vehicles electronically. You do not need to print anything or bring paperwork to the DMV. You can then renew your vehicle registration online through the DMV website, by mail, or in person at a DMV office.

When you renew online or by mail, the DMV automatically checks that your smog check is current. If it is not, your renewal will be delayed until you pass the test. If you renew in person at a DMV office, bring your registration renewal notice and your vehicle registration card, and the staff will confirm your smog check status before processing your renewal.

What to do if you cannot find a smog test station

The official smog check locator on the California Bureau of Automotive Repair website lets you search for certified test stations by zip code, city, or county. You can filter results by the type of vehicle you own — gasoline, diesel, or electric. Most areas have multiple stations within a short drive, and many are open on weekends.

If you live in a rural area with few nearby stations, you may need to travel farther or plan ahead. Some stations are busier during certain times of year, especially as registration renewal important date approach. Calling ahead to ask about wait times can save you a trip. If you cannot reach a station in your area, contact your local air quality management district for guidance on where to test.

Frequently Asked Questions

Can I get an extension if I miss my smog check important date?

No, but you can renew your registration late and still register your vehicle as long as you have a current smog check. If your registration has already expired, you will owe a late renewal fee. The best approach is to schedule your smog check before your registration expires, even if it means testing a few weeks early.

Do I need a smog check if I am selling my car?

Yes, if the vehicle is still registered in California. The seller must provide a smog check report to the buyer before the sale is complete. The smog check must have been done within 30 days of the sale. If you are buying a used car, ask the seller for proof that the smog check was recently completed.

What if my vehicle is registered out of state but I live in California?

You must register your vehicle in California within 20 days of moving to the state. Once you register it in California, it will be subject to California smog check requirements. You will need to pass a smog check as part of your initial California registration.

How much does a smog check cost?

The state sets a maximum fee of around $50 to $70 for a smog check, though the exact amount varies by test station and vehicle type. Some stations charge less. The fee covers the test itself; if you fail and need to retest, the retest is free within 30 days. Repairs needed to pass the test are separate and depend on what your vehicle needs.

Can I take my smog check in a different county than where my vehicle is registered?

Yes, you can take your smog check at any certified test station in California, regardless of which county your vehicle is registered in. The results are reported to the DMV statewide, so it does not matter where you test. This is useful if you are traveling or if the nearest station to you is in a neighboring county.