The California smog check is a periodic emissions inspection that most gasoline vehicles must pass to renew registration, change ownership, or be registered in the state for the first time. Inspections are run every two years for renewal, and the certificate stays valid for 90 days after the test.1Bureau of Automotive Repair. Smog Check: When You Need One and What’s Required The program is administered by the Bureau of Automotive Repair (BAR), and results are transmitted electronically to the DMV.
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.1Bureau of Automotive Repair. Smog Check: When You Need One and What’s Required For renewals, the DMV prints a notice on your renewal statement when a check is due, and the cycle is biennial.
Selling a vehicle? You, the seller, must give the buyer a valid smog certification at the time of sale. Without it, the buyer cannot complete the title transfer.2California State Department of Motor Vehicles. Smog Inspections
What the Inspection Actually Tests
The check has up to three parts depending on the vehicle’s model year, fuel, and where it’s registered.
For model year 2000 and newer gasoline vehicles, the core of the inspection is an OBD-II electronic test. The technician plugs into the vehicle’s diagnostic port and confirms that the on-board readiness monitors have completed and that no emissions trouble codes are stored. On gasoline vehicles from 2000 forward, only the evaporative system monitor is permitted to be incomplete for the vehicle to still pass.3Bureau of Automotive Repair. On-Board Diagnostic Test Reference If you recently disconnected the battery or had repair work done, expect to drive the car through a normal drive cycle before those monitors reset.
Older vehicles from model years 1976 through 1999 get a more physical test. In “enhanced” areas of the state that have not met federal ozone and carbon monoxide standards, they run on a dynamometer that measures tailpipe emissions under simulated driving load.4Bureau of Automotive Repair. Smog Check Reference Guide 2025 In “basic” areas, a simpler two-speed idle test is used.
Every inspection also includes a visual check of emissions control components — the catalytic converter, the EGR system, and the under-hood emissions label among them. A missing, disconnected, or modified part fails the vehicle regardless of what the OBD scan or tailpipe numbers show.
Where to Go and What It Costs
Only stations licensed by BAR can perform the inspection.5Bureau of Automotive Repair. About the Bureau of Automotive Repair They come in a few flavors:
- Test-Only stations inspect but do not repair.
- Test and Repair stations do both.
- STAR-certified stations meet higher performance standards and are the only shops authorized to inspect vehicles the DMV has “directed” there, including suspected gross polluters. Your renewal notice will tell you if your vehicle must go to a STAR station.
There is no state-set price ceiling. The statewide average inspection ran about $68 in early 2026, with individual stations charging roughly $50 at budget test-only locations and $77 or more at full-service shops.6Bureau of Automotive Repair. Smog Check Executive Summary Report February 2026 A certificate fee of $8.25 is added on top.
Which Vehicles Are Exempt
Not every vehicle needs an inspection, and the exemptions depend on both the transaction and the vehicle itself.
For registration renewals, vehicles eight model years old or newer skip the biennial test. In place of the inspection, owners pay an annual smog abatement fee of roughly $20 to $25 with registration.1Bureau of Automotive Repair. Smog Check: When You Need One and What’s Required For ownership transfers, vehicles four model years old or newer are exempt; the new owner pays a one-time $8 smog transfer fee instead.7California State Department of Motor Vehicles. Registration Fees
Several categories are permanently exempt no matter the transaction:
- Gasoline vehicles of model year 1975 and older
- Diesel vehicles of model year 1997 and older, or with a gross vehicle weight rating over 14,000 pounds
- Electric vehicles
- Motorcycles
Hybrids with a gasoline engine are not exempt. Because plug-in and conventional hybrids still produce tailpipe emissions when the engine runs, they follow the same schedule as any other gasoline vehicle.2California State Department of Motor Vehicles. Smog Inspections
What Happens If Your Vehicle Fails
A failed inspection blocks registration renewal, sale, or initial registration until the vehicle is repaired and passes a retest. Repair costs vary widely: an oxygen sensor may run $100 to $300, while a catalytic converter can exceed $1,000. California offers three routes that can reduce that bill.
Repair Assistance Through CAP
BAR’s Consumer Assistance Program (CAP) helps income-eligible owners pay for emissions repairs after a failed smog check.8Bureau of Automotive Repair. Repair or Retire Your Vehicle with the Consumer Assistance Program Assistance is capped by model year:
- Model year 1996 and newer: up to $1,450
- Model year 1976 to 1995: up to $1,100
You pay a co-payment equal to 20% of the total repair cost, or the amount exceeding the program maximum, whichever is greater.9Bureau of Automotive Repair. Apply for Repair Assistance Work must be done at a CAP-approved station.
Vehicle Retirement Payments
If repairs don’t make sense, CAP will pay you to take the vehicle off the road permanently.10Bureau of Automotive Repair. Retire Your Vehicle The payment depends on your income and the vehicle’s inspection status:
- $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 do not meet income requirements but whose vehicle failed its most recent inspection
The Repair Cost Waiver
If you have already spent a threshold amount on emissions repairs and the vehicle still won’t pass, you may qualify for a waiver that lets you register the vehicle anyway. The regulation sets a minimum repair expenditure starting at $650, adjusted every two years by the Consumer Price Index.11New York Codes, Rules and Regulations. 16 CCR 3340.43 – Repair Cost Limit The current minimum runs about $850. A BAR Referee reviews the application, and a granted waiver allows registration for up to two years while you keep working toward compliance. Vehicles that fail the visible smoke portion of the inspection face additional waiver restrictions.
Check Your Federal Emissions Warranty First
Before paying anything out of pocket, look at whether the failed part is under warranty. The Clean Air Act requires manufacturers to cover emissions components, and the warranty runs from the original sale date, so it can still apply to a used vehicle.12U.S. Environmental Protection Agency. Frequent Questions Related to Transportation, Air Pollution, and Climate Change
Most emissions-related parts carry a basic warranty of 2 years or 24,000 miles. The components most likely to cause a smog failure carry an extended warranty of 8 years or 80,000 miles, including the catalytic converter, the electronic emissions control module, and the onboard diagnostic computer.13eCFR. 40 CFR 85.2103 – Emission Warranty Inside that window, the manufacturer must repair a covered component at no cost to you.
Bringing a Vehicle from Out of State
New California residents have 20 days after establishing residency to apply for California registration.14California Legislative Information. California Vehicle Code 4152.5 Any non-exempt vehicle must pass a smog check as part of that initial registration.
There is one extra hurdle for newer out-of-state vehicles. If yours has fewer than 7,500 miles on the odometer and was built to meet federal emissions standards only, it generally cannot be registered in California unless a specific exemption applies.15California State Department of Motor Vehicles. California Noncertified/Direct Import Vehicle Exemptions Check the Vehicle Emission Control Information (VECI) label under the hood; a 50-state-certified vehicle will say so on the label. Once the odometer passes 7,500 miles, the CARB certification requirement drops away and the vehicle just needs to pass a standard smog check.
Tampering Is a Separate Problem
Removing a catalytic converter, installing a defeat device, or disabling the OBD-II system to pass an inspection is illegal under federal and California law. The federal Clean Air Act prohibits removing or disabling any emissions control device and prohibits selling or installing parts designed to bypass one, with civil penalties reaching up to $2,500 per violation for individuals and up to $25,000 per vehicle for manufacturers and dealers.16Office of the Law Revision Counsel. 42 U.S. Code 7524 – Civil Penalties The visual portion of the smog check is designed to catch these modifications, and a vehicle that fails visual inspection is not eligible for the repair cost waiver and cannot pass until the original equipment is restored.