A California smog check is the state’s periodic vehicle emissions inspection, and you need to pass one to renew your registration every two years, to sell a vehicle, or to register a vehicle in California for the first time. The Bureau of Automotive Repair (BAR) runs the program under emissions standards set by the California Air Resources Board, which are stricter than the federal rules.1California Air Resources Board. About Most gasoline-powered cars more than eight model years old are in the program; electric cars, motorcycles, and the oldest vehicles are not.
When You Need a Smog Check
Three transactions trigger the requirement: renewing your registration, transferring ownership, and registering a vehicle in California for the first time.2Bureau of Automotive Repair. Smog Check: When You Need One and What’s Required For renewals, the inspection is biennial. The DMV marks your renewal notice when one is due, so you don’t have to track the two-year cycle yourself.
If you’re selling a vehicle, you as the seller must give the buyer a valid smog certification at the time of sale.3California State Department of Motor Vehicles. Smog Inspections Without one, the buyer can’t complete the title transfer. A smog certificate stays valid for 90 days, and the station sends the result electronically to the DMV, so you don’t need to carry a paper copy to the registration counter.2Bureau of Automotive Repair. Smog Check: When You Need One and What’s Required
Which Vehicles Are Exempt
Age is the biggest exemption. For renewals, vehicles eight model years old or newer skip the inspection and instead pay a smog abatement fee of roughly $20 to $25 with annual registration.2Bureau of Automotive Repair. Smog Check: When You Need One and What’s Required For ownership transfers, the cutoff is four model years old or newer; the new owner pays a one-time $8 smog transfer fee instead.4California State Department of Motor Vehicles. Registration Fees
Several categories are permanently exempt, no matter the transaction:
- Gasoline vehicles model year 1975 and older
- Diesel vehicles model year 1997 and older, or with a gross vehicle weight rating over 14,000 pounds
- Electric vehicles
- Motorcycles
Hybrids are not exempt. Both plug-in and conventional hybrids still burn gasoline, so they follow the same smog check schedule as any other gas-powered car.3California State Department of Motor Vehicles. Smog Inspections
What It Costs and Where to Go
The state doesn’t cap smog check prices. As of early 2026, the statewide average runs about $68, with individual stations charging roughly $50 at budget test-only shops and $77 or more at full-service garages.5Bureau of Automotive Repair. Smog Check Executive Summary Report February 2026 A certificate fee of $8.25 is added on top.
Every station performing the inspection has to be licensed by BAR.6Bureau of Automotive Repair. About the Bureau of Automotive Repair Stations come in three varieties. Test-Only stations inspect but can’t repair. Test and Repair stations can do both. STAR-certified stations meet higher performance standards and are the only places authorized to test vehicles the DMV has flagged, including suspected gross polluters. If your vehicle has been directed to a STAR station, your renewal notice will say so.
What the Test Actually Checks
The inspection combines up to three parts depending on your vehicle’s age and where you live. Vehicles from model year 2000 and newer run primarily through an on-board diagnostic (OBD-II) test, which plugs into the car’s computer and reads emissions-related trouble codes and readiness monitors.7Bureau of Automotive Repair. On-Board Diagnostic Test Reference If you recently disconnected the battery or had work done, those monitors may need time to reset by driving normally before the vehicle can pass.
Older vehicles, roughly model years 1976 through 1999, get a tailpipe test. In parts of the state that haven’t met federal air quality standards, that means a dynamometer run that measures emissions under simulated driving load; elsewhere, a simpler two-speed idle test.8Bureau of Automotive Repair. Smog Check Reference Guide 2025
Every smog check also includes a visual inspection of emissions components: the catalytic converter, exhaust gas recirculation system, and the underhood emissions control label, among others. If something is missing, modified, or disconnected, the vehicle fails on the spot, regardless of what the OBD or tailpipe numbers say.
If Your Vehicle Fails
A failure blocks your registration or sale until the vehicle is repaired and passes a retest. Costs run anywhere from $100 to $300 for an oxygen sensor to over $1,000 for a catalytic converter. California offers three paths that can reduce what you pay out of pocket.
Consumer Assistance Program Repairs
BAR’s Consumer Assistance Program (CAP) helps income-eligible owners pay for emissions repairs after a failure.9Bureau of Automotive Repair. Repair or Retire Your Vehicle with the Consumer Assistance Program The maximum depends on model year:
- Model year 1996 and newer: up to $1,450 in repair assistance
- Model year 1976 to 1995: up to $1,100 in repair assistance
You pay a 20% co-payment of the total repair cost, or the amount over the program maximum, whichever is greater, and the work has to be done at a CAP-approved station.10Bureau of Automotive Repair. Apply for Repair Assistance
Vehicle Retirement
If repair isn’t worth it, CAP will pay you to retire a high-polluting vehicle permanently.11Bureau of Automotive Repair. Retire Your Vehicle The payment depends on income and recent smog history:
- $2,000 for income-eligible owners whose vehicle failed its most recent smog check
- $1,500 for income-eligible owners whose vehicle had a completed smog check (pass or fail) within the last 180 days
- $1,350 for owners who don’t meet income limits but whose vehicle failed its most recent smog check
Repair Cost Waiver
If you’ve already spent a significant amount trying to pass and the vehicle still won’t, a repair cost waiver can let you register anyway. The regulation sets a minimum repair expenditure starting at $650, adjusted every two years to the Consumer Price Index; recent adjustments put it near $850.12New York Codes, Rules and Regulations. 16 CCR 3340.43 – Repair Cost Limit A BAR Referee reviews the request, and if granted, the waiver allows registration for up to two years. Vehicles that fail the visible smoke portion of the test face added restrictions on eligibility.
Check the Federal Emissions Warranty First
Before you pay for any repair, check whether the part is still under federal warranty. The Clean Air Act requires manufacturers to warrant most emissions components for 2 years or 24,000 miles, and major components (including catalytic converters, the electronic emissions control module, and the onboard diagnostic computer) for 8 years or 80,000 miles.13eCFR. 40 CFR 85.2103 – Emission Warranty These warranties count from the original sale date and transfer with the vehicle, so used-car owners qualify too.14U.S. Environmental Protection Agency. Frequent Questions Related to Transportation, Air Pollution, and Climate Change If a covered part caused your failure and you’re within the window, the manufacturer must repair it at no cost.
Bringing a Vehicle from Out of State
If you move to California with a vehicle registered elsewhere, you have 20 days after establishing residency to apply for California registration.15California Legislative Information. California Vehicle Code 4152.5 Any non-exempt vehicle must pass a smog check as part of that registration.
There’s one wrinkle for newer vehicles. If your car has fewer than 7,500 miles on the odometer and was built only to federal emissions standards rather than California’s, you generally can’t register it here unless a specific exemption applies.16California State Department of Motor Vehicles. California Noncertified/Direct Import Vehicle Exemptions The Vehicle Emission Control Information label under the hood will say whether the vehicle is certified for all 50 states. Once the odometer passes 7,500 miles, that requirement drops away and a standard smog check is enough. Most used vehicles coming into California fall into this easier category.
Missing the 20-day deadline, or a renewal deadline, triggers immediate penalties that stack with time:17California State Department of Motor Vehicles. Penalties
- 1 to 10 days late: 10% of the vehicle license fee, plus $10 registration late fee, plus $10 CHP late fee
- 11 to 30 days late: 20% of the vehicle license fee, plus $15 in combined late fees
- 31 days to one year late: 60% of the vehicle license fee, plus $30 in combined late fees
- Over one year late: 80% of the vehicle license fee, plus $50 in combined late fees
- Over two years late: 160% of the vehicle license fee, plus $100 in combined late fees
Waiting for a smog check repair does not pause this clock. If the car needs emissions work that takes weeks, penalties keep accumulating in the background.
Why Tampering Isn’t a Shortcut
Removing a catalytic converter, installing a defeat device, or disabling the OBD-II system to pass a smog check violates both federal and California law. The federal Clean Air Act prohibits removing or disabling any emissions control device, and prohibits selling or installing parts meant to bypass them.18Office of the Law Revision Counsel. 42 U.S. Code 7524 – Civil Penalties Civil penalties reach up to $2,500 per violation for individuals and up to $25,000 per vehicle for manufacturers and dealers, and each vehicle or part counts separately.
The visual portion of the smog check exists specifically to catch this. A vehicle that fails the visual inspection cannot receive a repair cost waiver and will not pass until the original equipment is back in place.