Key takeaways
- Most gasoline vehicles need a smog check every two years at renewal in covered counties, and when they're sold.
- Gas vehicles less than eight model years old, 1975 and older, and electric vehicles are exempt from renewal smog checks.
- Sellers must give the buyer a valid smog certificate unless the vehicle is four or fewer model years old; then the buyer pays an $8 transfer fee instead.
California's Smog Check program, run by the Bureau of Automotive Repair (BAR), tests vehicle emissions. You'll usually need a smog check in two situations: at registration renewal and when a vehicle is sold. Your DMV renewal notice tells you if one is due.
At registration renewal: every two years
In counties covered by the program, most gasoline vehicles need a smog check every two years when the registration is renewed. You must complete it before DMV can finalize your renewal. You can still pay your fees on time to avoid late penalties.
Counties that require it at renewal
The DMV lists these 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 DMV's list may not be complete, and it doesn't show which parts of a county are covered. Don't assume you're exempt because your county isn't on the DMV list.
In some counties only certain ZIP codes are covered. Your renewal notice is the final word.
Who's exempt
According to the DMV, you don't need a smog check at renewal for:
- gasoline vehicles less than eight model years old, which instead pay a smog abatement fee with registration (the amount is on your renewal notice);
- gasoline vehicles of model year 1975 or older;
- electric vehicles;
- diesel vehicles of model year 1997 or older, or over 14,000 lbs; and
- natural-gas vehicles over 14,000 lbs.
When you sell a vehicle
The seller must give the buyer a valid smog certificate (Vehicle Code §24007(b)(2)). The main exception is a non-diesel vehicle four or fewer model years old: then the buyer pays an $8 smog transfer fee at the DMV instead. Transfers between certain close family members can also be exempt.
See Selling a car in California for the full seller checklist.
Change coming in 2027: San Joaquin Valley
In a January 2026 presentation, BAR explained that the San Joaquin Valley did not meet a federal ozone standard. Smog Check program changes will begin in 2027. In practice, the new-vehicle exemption is expected to shrink from eight to seven model years in San Joaquin, Stanislaus, Merced, Madera, Fresno, Kings, Tulare and western Kern counties. Watch your renewal notice and BAR announcements if you live there.
Getting the test done
- Use a BAR-licensed Smog Check station. Your notice may say you must use a STAR-certified station.
- The station sends results to DMV electronically, so you don't mail anything.
- If your vehicle fails, BAR's Consumer Assistance Program may help with repair costs or vehicle retirement, if you qualify.
Which rule applies to you?
| Your situation | What you need |
|---|---|
| Renewing a gas vehicle eight or more model years old in a covered county | A smog check every two years |
| Renewing a gas vehicle less than eight model years old | No smog check; pay the smog abatement fee shown on your renewal notice |
| Renewing an electric vehicle, or a gas vehicle from 1975 or earlier | No smog check |
| Selling a non-diesel vehicle four or fewer model years old | No certificate; the buyer pays the $8 smog transfer fee |
| Selling an older vehicle | The seller gives the buyer a valid smog certificate |
| Getting a car from a close family member | Usually no smog check (see the FAQ below) |
Common mistakes
- Waiting for the last week. If your car fails, you'll need time for repairs and a retest. Start early, and pay your registration fees on time either way.
- Using the wrong kind of station. If your notice says STAR, a regular station won't satisfy it.
- Assuming your county is exempt. Some counties are covered only in certain ZIP codes. Trust your renewal notice over a county list.
- Selling with an old certificate. For a sale, a smog certificate is good for 90 days. A test from months ago may have expired by the time the buyer transfers the title.
Frequently asked questions
How often do I need a smog check in California?
Most gasoline vehicles need a smog check every two years at registration renewal, if you live in a covered county or ZIP code. Your DMV renewal notice tells you when one is due. You may also need one when you sell a vehicle.
Do electric cars need a smog check in California?
No. The DMV lists electric vehicles as exempt from smog checks at renewal.
Do hybrid cars need a smog check?
The DMV's exemption list names electric vehicles but doesn't mention hybrids, so don't assume a hybrid is exempt. Your renewal notice says whether a check is due.
Who pays for the smog check when you sell a car in California?
The seller does. Under Vehicle Code §24007(b)(2), the seller must give the buyer a valid smog certificate. The main exception is a non-diesel vehicle four or fewer model years old, where the buyer pays an $8 smog transfer fee instead. See the full seller checklist.
How long is a smog certificate good for when selling a car?
A smog certificate is valid for 90 days for a sale. Vehicle Code §4000.1 refers to the certificate's 90-day validity period. The buyer's transfer application should reach DMV within that window.
Do I need a smog check if a family member gives me a car?
Usually not. The DMV says a car given by a spouse, domestic partner, sibling, child, parent, grandparent or grandchild is generally exempt. A smog check is still required if the relative bought the car for you without first titling it in their own name.
Can I renew my registration before I pass a smog check?
You can pay your fees on time, but DMV won't finalize the renewal until it gets your smog certification. Paying first avoids late penalties. See how to renew your registration.
Sources
We use primary sources: statutes, court rules, official forms and government pages. Read our editorial standards.