How Often Do You Need a Smog Check in California?

In California, most vehicles need a smog check every two years to renew their registration. That biennial cycle is the short answer to how often you need a smog check in California, but two other events also trigger an inspection: selling the vehicle and registering it in the state for the first time. A passing certificate is good for 90 days, and your DMV renewal notice will tell you whether a smog certification is required for that cycle.1Bureau of Automotive Repair. Smog Check: When You Need One and What’s Required

The Three Times a Smog Check Is Required

Three situations put a smog check on your calendar:

  • Registration renewal every two years. If your DMV renewal notice says “Smog Certification Required,” you need a passing inspection before you can renew. Non-exempt vehicles hit this every other year.
  • Change of ownership. The seller has to give the buyer a valid smog certificate at the time of sale. Vehicles four model years old or newer skip the inspection; the new owner pays a smog transfer fee instead.
  • Initial California registration. A vehicle moving in from another state needs a smog check before it can be registered here, no matter how old it is or how recently it was tested elsewhere.

The 90-day validity window matters. If you test too early, the certificate can expire before your registration deadline and you’ll have to test again.1Bureau of Automotive Repair. Smog Check: When You Need One and What’s Required

Which Vehicles Are on the Biennial Schedule

The every-two-years rule applies to:

  • Gasoline, hybrid, and alternative-fuel vehicles from model year 1976 and newer
  • Diesel vehicles from model year 1998 and newer with a gross vehicle weight rating of 14,000 pounds or less

RVs, motorhomes, collector cars, and government vehicles within those ranges are included.1Bureau of Automotive Repair. Smog Check: When You Need One and What’s Required

Vehicles That Never Need a Smog Check

Some vehicles are permanently exempt and never appear on the biennial schedule:

  • Gasoline-powered vehicles from 1975 or older, including motorcycles and trailers of any year
  • Diesel vehicles from 1997 or older, and any diesel with a GVWR over 14,000 pounds
  • All electric vehicles

The Eight-Year Break for Newer Vehicles

If your gasoline, hybrid, or alternative-fuel vehicle is eight model years old or newer, you don’t get a smog inspection at all. Instead, you pay a smog abatement fee with your registration. In 2026, that covers model year 2018 and newer. Once the vehicle enters its ninth model year, the biennial cycle begins and you’re back to a smog check every two years.2California State Department of Motor Vehicles. Smog Inspections

Family Transfers

Transferring a vehicle between immediate family members doesn’t require a smog check. That covers a spouse, domestic partner, sibling, child, parent, grandparent, or grandchild. One exception: if a family member bought the car specifically for you but never titled it in their own name first, the DMV treats it as a standard purchase and an inspection is required.2California State Department of Motor Vehicles. Smog Inspections

What If Your Car Is Temporarily Out of State

When your renewal comes due and the vehicle is temporarily outside California, you can apply for a temporary smog exemption using DMV Form REG 5103. You’ll need to state where the vehicle is, why it can’t be registered in that state, and confirm you’ll get it tested once it returns. Vehicles garaged in certain border cities in Nevada (including Reno, Sparks, and Carson City) and in Tijuana and Tecate, Mexico, are not eligible.3California DMV. Application for Temporary Smog Exemption for a Vehicle Located Out-of-State

Where to Get the Inspection

Smog checks are done at stations licensed by the Bureau of Automotive Repair (BAR), which runs a station locator. Some vehicles are directed to STAR-certified stations, which meet higher performance standards; if that applies to you, your DMV renewal notice will say so.4CA.gov. Find an Auto Shop When a vehicle passes, the station sends the certificate of compliance to the DMV electronically, so you don’t have to hand-carry paperwork to complete your renewal.5Bureau of Automotive Repair. Check a Vehicle’s Inspection History

What Happens If You Miss It

Skipping your smog check means you can’t renew your registration, and California’s late penalties escalate fast:

  • 1–10 days late: 10% of the vehicle license fee plus $20 in flat fees
  • 11–30 days late: 20% of the license fee plus $30
  • 31 days to one year late: 60% of the license fee plus $60
  • More than one year late: 80% of the license fee plus $100
  • More than two years late: 160% of the license fee plus $200

Driving with expired registration is also a citable offense on its own.6California State Department of Motor Vehicles. Penalties The inspection takes less than an hour, so the practical rhythm for most drivers is straightforward: watch for the “Smog Certification Required” line on your renewal notice, get tested within the 90-day window before your registration is due, and keep the two-year cadence going for as long as you own the vehicle.