STAR stations are California's official smog test network, and you find them by county and location through the official STAR program website

California's STAR (Smog Test And Repair) program runs the state's official smog testing network. If you need a smog test in California, a STAR station is where you go — these are the only stations that can issue the smog certificates the state requires for vehicle registration and transfers. You locate a STAR station by entering your ZIP code or county into the STAR program locator on the California Bureau of Automotive Repair website.

STAR stations are private businesses — repair shops, tire shops, and independent testing facilities — that have been certified by the state to perform smog tests. They are not government offices. When you arrive at a STAR station, you bring your vehicle and your registration documents, the technician runs the test, and you receive a certificate on the spot if your vehicle passes. The test itself takes 10 to 30 minutes depending on the station's workload.

Key Takeaways

  • Find STAR stations through the official locator at the California Bureau of Automotive Repair website by entering your ZIP code or county.
  • STAR stations are private certified businesses, not government facilities, and they are the only places that can issue state-required smog certificates.
  • Test costs vary by station and vehicle type, typically ranging from $30 to $70, and you receive your certificate when ready if you pass.
  • You need your vehicle registration and proof of current insurance to bring to the test, and some stations require an appointment while others accept walk-ins.
  • If your vehicle fails, the station provides a report showing which emissions standards were not met, and you can take it to any repair shop to fix the problems.

How to locate a STAR station in your area

The California Bureau of Automotive Repair maintains the official STAR station locator at smogcheck.ca.gov. On that site, you enter your ZIP code or select your county, and the tool displays all certified STAR stations near you, including their addresses, phone numbers, and hours. Some stations show whether they accept appointments or walk-ins, though you may need to call to confirm current availability.

If you cannot access the website, you can call the Bureau of Automotive Repair directly at 1-800-622-7733 to ask for STAR stations in your area. They can also tell you whether a specific station is currently operating, since some close or change hours seasonally. When you call a station directly, ask whether they test your vehicle type — some stations specialize in light-duty vehicles while others also test heavy-duty trucks or motorcycles.

What documents and information to bring

Bring your vehicle registration and proof of current insurance. The technician will need to see both before running the test. If you are testing a vehicle you recently purchased, bring the bill of sale or purchase agreement along with the registration. Some stations also ask for your driver's license, though this is not required by the state.

If your vehicle has had recent repairs or modifications, bring documentation of that work — particularly if you had emissions-related repairs done. This can help the technician understand the vehicle's history if it is close to passing or failing. You do not need to bring your smog certificate from a previous test, though having it can be useful if you are tracking your vehicle's emissions trend over time.

Test costs and what affects the price

STAR station fees vary by location and vehicle type. Most stations charge between $30 and $70 for a basic smog test on a light-duty passenger vehicle. Diesel vehicles, motorcycles, and heavy-duty trucks often cost more — sometimes $50 to $100 — because the test procedure is different. Some stations charge extra if you need a retest after failing, though many include one retest in the original fee.

The state does not set a fixed price for smog tests; each STAR station sets its own fee. If you want to compare prices, call two or three stations in your area before you go. Payment methods vary by station — some accept cash only, while others take credit cards or checks. Ask about payment options when you call to confirm they can test your vehicle type.

What happens during the test and after you pass or fail

When you arrive, the technician will inspect your vehicle's emissions equipment — the catalytic converter, oxygen sensors, and related systems — to make sure nothing is obviously damaged or missing. Then they connect your vehicle to a dynamometer (a machine that simulates driving) or a tailpipe probe, depending on your vehicle's age and type. The machine measures your vehicle's emissions output and compares it to state standards for your vehicle's year and model.

If your vehicle passes, you receive a smog certificate when ready, either printed or digital depending on the station. That certificate is valid for 30 days, and you use it to register or transfer your vehicle. If your vehicle fails, the station provides a detailed report showing which emissions standards were not met and which systems are likely causing the problem. You can take that report to any repair shop — not necessarily the STAR station — to have the problems fixed, then return for a retest.

What to do if your vehicle fails the smog test

A failed smog test report identifies which emissions standards your vehicle exceeded — usually nitrogen oxides, particulate matter, or hydrocarbons — and which systems may need attention. Common causes include a faulty oxygen sensor, a failing catalytic converter, a clogged air filter, or an engine misfire. The report does not diagnose the exact problem, but it narrows the field for a repair shop.

You can take your vehicle to any repair shop, not just the STAR station where you failed. Many independent shops and dealerships can diagnose and repair emissions problems. After repairs are complete, you return to any STAR station for a retest. Some stations waive or reduce the retest fee if you failed there originally, though this varies by location. Keep your failed smog certificate and repair receipts together in case you need to show the state that you made a good-faith effort to repair the vehicle.

Appointment scheduling and wait times

Some STAR stations operate by appointment only, while others accept walk-ins on a first-come, first-served basis. Call ahead to ask which applies to the station you plan to visit. During peak registration periods — typically the end of each month and the end of the year — wait times can stretch to several hours at busy stations. Scheduling an appointment, when available, usually cuts your wait time to 15 to 30 minutes.

If you are on a tight timeline because your registration is expiring, schedule your test at least two weeks before the expiration date. This gives you time to fix any problems and retest if needed. If your registration has already expired, you can still get a smog test, but you cannot legally drive the vehicle to the test station — you will need to have it towed or transported on a flatbed.

Frequently Asked Questions

Can I get a smog test at a non-STAR station?

No. Only STAR-certified stations can issue the smog certificate California requires for registration and transfers. Tests performed at non-certified shops are not valid for state purposes. If you see a station advertising smog tests but it is not listed on the STAR locator, call the Bureau of Automotive Repair to verify its status before going.

How long is a smog certificate valid?

A smog certificate is valid for 30 days from the date of issue. You must complete your vehicle registration or transfer within that window. If your certificate expires before you register, you will need to get a new test. Some vehicles are exempt from smog testing — typically those under six years old or those registered as classic cars — so check your registration notice to see if a test is required.

What if I just moved to California and need a smog test?

If you are registering an out-of-state vehicle in California for the first time, you need a smog test unless the vehicle is brand new or qualifies for an exemption. Use the STAR locator to find a station in your new county. Bring your out-of-state registration, proof of insurance, and your driver's license. The test is the same as for any other vehicle.

Can I retest at a different STAR station if I fail?

Yes. You can take your vehicle to any STAR station for a retest, not just the one where you failed. Some stations offer a reduced retest fee if you failed there originally, but you are not required to return to the same location. Shop around if you want to compare retest prices.

What if my vehicle is too old or too new to test?

Vehicles manufactured before 1976 and some vehicles under six years old are exempt from smog testing in California. Check your registration notice or call the Bureau of Automotive Repair to confirm whether your vehicle needs a test. If you are unsure, a STAR station can tell you when you call — they test vehicles every day and know the exemption rules.