Most vehicles in California need a smog check every two years, at the point when you renew your registration. There are also a few moments outside that two-year cycle when a test is required, and several groups of vehicles that get a break. Which situation you are in decides whether your car is due this year.
This guide covers the two-year rule, the other times a test is triggered, which vehicles skip it, and how to find out where you stand.
The Short Answer: Every Two Years at Renewal
For most gasoline, hybrid and diesel vehicles, California requires a smog check every other year as a condition of renewing your registration. Your DMV renewal notice tells you whether a test is needed for that renewal cycle, and the smog certificate has to be on file before the DMV will complete the renewal.
Diesel vehicles follow the same pattern for model year 1998 and newer, with a gross vehicle weight rating under 14,001 pounds. If you drive a diesel, diesel vehicle smog checks in California has the details.
When Else Do You Need a Smog Check?
The two-year cycle is the one most people know, but it is not the only trigger.
When You Sell a Car
A change of ownership usually requires a current smog certificate from the seller. The Bureau of Automotive Repair says vehicles four model years old or newer do not need a test for a change of ownership, which is why selling a nearly new car is simple and selling an older one is not. If you are in the middle of a sale, read whether you can sell a car without a smog check in California first.
When You Bring a Car From Another State
A car registering in California for the first time needs a smog check, including one previously registered elsewhere. The age-based breaks that apply to renewals do not simply carry over to a car that is new to the state, so confirm with the DMV if you think yours qualifies. We explain the whole process in do out-of-state vehicles need a smog check in California.
When You Fail and Need a Retest
A failed test does not reset your two-year clock. You still need a passing result, so you repair the problem and return for a retest. What to do if your vehicle fails a smog check covers the next steps.
Which Vehicles Get a Break?
Some vehicles skip the biennial test entirely, and some skip it for a set number of years.
Newer gasoline vehicles. Vehicles eight model years old or newer do not need a smog check for registration renewal. Instead, owners pay a smog abatement fee with their registration. Once a car ages past that window, the test begins. In 2026, for example, the 2018 model year is the first to lose the exemption. Our 2026 California smog rules post walks through the math.
Older vehicles. Gasoline, hybrid and alternative-fuel vehicles from model year 1975 and older are exempt, and so are diesel vehicles from model year 1997 and older.
Electric vehicles and motorcycles. Fully electric vehicles and motorcycles do not need a smog check. Hybrids are not exempt and follow the same rules as gasoline cars, as smog checks for hybrid vehicles explains.
Heavy diesel vehicles. Diesel vehicles over 14,000 pounds gross vehicle weight rating are exempt.
Some locations. A few rural areas of the state have different requirements, which is another reason to rely on your renewal notice. Monterey Park and the rest of the Los Angeles area follow the standard rules.
The full list is on the Bureau of Automotive Repair’s smog check page, and our guide to which vehicles need smog checks in California breaks it down by vehicle type.
How to Find Out If Your Car Is Due
Start with your DMV registration renewal notice. It says whether a smog certification is required for the coming renewal, and sometimes whether you must use a STAR-certified station. If that is the case, what a STAR station smog check is explains what it means for you.
You can also check what is on record for your vehicle, including the date of its last test, using the free lookup in our guide to checking your vehicle’s smog check history. If you are not sure a test is due, read what to do if your vehicle is due for a smog check soon.
When Should You Get It Done?
A passing smog certificate is valid for 90 days, so you can test well before your registration expires without losing it. The sweet spot is a few weeks ahead of your deadline, which leaves room to handle a failed result without a late fee. How long a smog check is good for in California explains the window.
The test itself is quick, usually 15 to 30 minutes, as we cover in how long a smog check takes. Bring your paperwork using our documentation checklist, and run through the pre-test checklist so a fixable problem does not cost you a second trip.
What Happens If You Skip a Smog Check?
The DMV will not complete your registration renewal without the required smog certificate. That means your registration can expire, late fees can build up, and driving with expired registration can get you cited. There is no workaround for a car that needs a test, so it is better to handle it early than to rush at the end of the month.
If repairs are what is holding you up, you may have options. California’s Consumer Assistance Program can help eligible owners with repair costs, and we explain who qualifies in California’s Consumer Assistance Program for smog repairs.
Frequently Asked Questions
Do I need a smog check every year in California?
No. Most vehicles need one every two years at renewal. Newer gasoline vehicles skip the test and pay an annual smog abatement fee instead.
How often do I need a smog check for a hybrid?
The same as a gasoline car, which is every two years once the vehicle is past the newer-vehicle exemption. Hybrids are not exempt like fully electric vehicles.
Do I need a smog check when I buy a used car?
The seller is generally responsible for providing a passing certificate on a sale, unless the vehicle is four model years old or newer. Check the details before you pay.
Do I need a smog check for a new car?
Not for renewals during the first eight model years, and not for a change of ownership within the first four. A car new to California from another state is a different case, so see our out-of-state guide.
How long does a smog check certificate last?
90 days from the test date.
Can I check when my last smog check was?
Yes. The state’s vehicle test history tool shows previous results for free, using a VIN or license plate.
Get Your Smog Check at AB Smog Check in Monterey Park
If your renewal notice says you are due, we can test you the same day. Our STAR-certified station handles both regular and STAR-required vehicles, so you only need one stop, and you get a plain explanation of your result afterward.
AB Smog Check 501 E Garvey Ave, Monterey Park, CA 91755 Phone: 626-280-2678
Hours: Monday to Friday, 9:00 am to 5:00 pm Saturday, 9:00 am to 3:00 pm Sunday, closed
No appointment necessary. Pass or have a free re-test.
