Smog Check in California
Gas, hybrid, and diesel cars are tested in 34 California counties through Smog Check. For 2026, that covers model years 1976 to 2018. Testing comes up every 2 years with registration renewal, and again when a car changes owners or is registered in California for the first time.
What cars have to get the test?
Model years that California tests in 2026 appear in the green band. Cars in the 8 most recent model years don't take the renewal test (they pay a smog abatement fee instead); diesels get no new-car exemption. Gas cars from 1975 and earlier and diesels from 1997 and earlier are exempt.
Look up your own car: enter its model year and fuel type.
California emissions test: the basics
| Program | Smog Check |
|---|---|
| Where | All 34 counties, listed in reverse: Yuba County, Yolo County, Ventura County, Tulare County, Tehama County, Sutter County, Stanislaus County, Solano County, Shasta County, Santa Cruz County, Santa Clara County, Santa Barbara County, San Mateo County, San Luis Obispo County, San Joaquin County, San Francisco County, San Benito County, Sacramento County, Orange County, Nevada County, Napa County, Monterey County, Merced County, Marin County, Madera County, Los Angeles County, Kings County, Kern County, Glenn County, Fresno County, Contra Costa County, Colusa County, Butte County, Alameda County |
| Fuels tested | Gas, hybrid, diesel |
| Model years tested in 2026 | 1976 to 2018 (diesels from 1998) |
| How often | Needed every 2 years when you renew the registration, and also at a sale or first registration in California |
| The test | A visual and functional inspection plus an OBD check for most cars from 2000 on, or a tailpipe test for older cars |
| Fee | Each station sets its own price, plus the $8.25 certificate fee |
| New cars | For the 8 newest model years, a smog abatement fee takes the place of the renewal test; diesels get no new-car exemption |
| Older cars | Gas cars from 1975 or earlier, and diesels from 1997 or earlier, are exempt |
| What to bring | If you have it, bring your DMV registration renewal notice |
| Waiver | Once emissions work totals at least $650 through a licensed smog check station, a one-time waiver for repair costs is available. |
How the test works, and what if the car fails?
For an OBD test, the inspector connects a reader to the port under the dashboard and pulls up what the car's computer has stored. The self-checks (readiness monitors) need to be complete, and the check engine light can't be on.
Mostly on older cars, a tailpipe test uses a probe in the exhaust to measure what comes out.
When a car fails, the report lists what failed. Fix the problem first, then return for a retest.
When the car still fails after repairs, California offers a waiver: a one-time waiver of repair costs once at least $650 in emissions repairs is done at a licensed smog check station.