California smog check requirements: what to bring and who needs one

For a California smog check you need the vehicle and, if you have it, the DMV renewal notice, which says whether a STAR station is required. You pay the station’s price plus the $8.25 state certificate when the car passes. The check engine light must be off, and after battery work the car needs a week or two of normal driving first.

• The renewal notice, if you have one. It says whether the vehicle must go to a STAR station.
• Payment for the inspection and the $8.25 certificate. Prices aren’t regulated, so compare first or bring a coupon.
• No check engine light. Fix the cause before the test; the car will not pass with it on.
• A normal week of driving after any battery replacement, dead battery or cleared codes, so the readiness monitors can finish. BAR suggests a week or two.
• Legal parts only. Aftermarket parts that affect emissions need a CARB exemption to pass the visual inspection (CARB).

The station must give you an estimate, and you approve it before the inspection starts (BAR).

In California, gasoline, hybrid and alternative-fuel vehicles from the 1976 model year on need smog checks, and so do diesels from 1998 on with a gross vehicle weight rating of 14,000 pounds or less. That covers motorhomes, collector cars and government vehicles too. Electric cars, motorcycles and trailers never need one.

Source: BAR, Smog Check.

You need a California smog check every other year at registration renewal once a gasoline car is more than eight model years old, when a vehicle more than four model years old changes owners, and when any covered vehicle is registered in California for the first time. Diesels get no new-vehicle exception. Your DMV renewal notice says when one is due.

A few rural areas require the check only at a change of ownership; your renewal notice is the final word. A certificate is valid for 90 days (how long a smog check takes and lasts).

For a registration expiring in 2026, gasoline and hybrid cars from the 2019 model year and newer skip the renewal smog check and pay the smog abatement fee instead, and those from 1975 and earlier are exempt for good. Cars from 1976 to 2018 need one every other year. Electric vehicles, motorcycles and trailers are always exempt.

Model years follow the DMV’s rule for the smog abatement fee (DMV). The full list of exemptions:

• Gasoline, hybrid and alternative-fuel vehicles from 1975 and earlier.
• Diesel vehicles from 1997 and earlier, or over 14,000 pounds GVWR.
• Natural gas vehicles over 14,000 pounds.
• Fully electric vehicles, motorcycles and trailers.
• Transfers between immediate family members, unless a relative bought the car for you without first titling it in their name.

Sources: BAR and DMV. More detail on edge cases in cars exempt from smog check in California.

Yes, in most cases. When you sell a car in California, you must give the buyer a smog certificate from a test passed within the last 90 days. You don’t need one for a gasoline, hybrid or alternative-fuel vehicle four model years old or newer, where the buyer pays an $8 smog transfer fee instead, or for a sale to an immediate family member. Diesels always need one.

The seller, not the buyer, is responsible for the certificate (DMV, BAR). A relative who bought the car for you without first titling it in their own name doesn’t count as a family transfer. If the car fails, see what to do after a failed smog check.

Yes, for vehicles California tests: gasoline and hybrid from 1976 on and diesel from 1998 on. One is required to register the vehicle here for the first time, including one bought in or previously registered in another state, at a licensed California station. If your California-registered car is out of state at renewal time, the DMV can grant a temporary exemption until it returns.

The first-registration rule is BAR’s (BAR, Smog Check). For a car temporarily outside California, file the DMV’s Application for Temporary Smog Exemption for a Vehicle Located Out-of-State (REG 5103) and get the smog check once the car is back.

Smog Check rules for ordinary cars didn’t change in 2026. The changes: a BAR regulation in effect since October 1, 2025 requires feasible readiness monitors to be complete to pass, phased in vehicle by vehicle; SB 1392 exempts qualifying pre-1981 collector cars from January 1, 2028; and repair help rose to $1,450 in 2025.

• Readiness monitors. A BAR regulation in effect since October 1, 2025 requires all readiness monitors that can feasibly be set to be complete for a vehicle to pass. BAR is phasing it in gradually, by vehicle, as data comes in (BAR).
• Collector cars, from 2028. SB 1392, signed September 16, 2026 (Chapter 245, Statutes of 2026), exempts qualifying collector vehicles built before the 1981 model year starting January 1, 2028. The cutoff moves up one model year each year until it covers vehicles built before 1986, from 2033 (SB 1392). Nothing changes for an ordinary car.
• Repair help went up. Since January 1, 2025, BAR’s Consumer Assistance Program pays up to $1,450 toward repairs on 1996-and-newer vehicles.

Most cars that fail a California smog check have a lit check engine light, readiness monitors that haven’t finished after battery work or cleared codes, missing or modified emissions parts, or, on older cars, high tailpipe readings. In BAR’s August 2026 report, 8.26% of initial inspections failed.

In BAR’s August 2026 report, 8.26% of initial inspections failed. The usual causes are a lit check engine light, monitors that haven’t finished, missing or modified emissions parts, and on older cars high tailpipe readings. The detail is in common smog check failures. If the car fails, here is what to do after a failed smog check; the state may help pay for repairs, and the vehicle’s past results are in its smog check history.