Star Smog Check is California's voluntary emissions testing program for vehicles that would otherwise fail a standard smog check
Star Smog Check is a repair information program run by the California Bureau of Automotive Repair. If your vehicle fails its regular smog inspection, Star allows you to take it to a participating repair shop where technicians diagnose the problem and perform repairs at a reduced cost. You then return to the smog station for a retest. The program exists because some vehicle owners face genuine barriers to fixing emissions problems—the repair cost can be steep, and without help, the car stays off the road.
The key difference between Star and a standard smog check is that Star is optional. You do not have to use it. But if your vehicle fails and you want to keep driving it legally, Star is often the most affordable path forward.
Key Takeaways
- Star Smog Check is available only after your vehicle fails a regular smog inspection; you cannot use it preemptively.
- You must take your vehicle to a Bureau-certified Star repair shop, not just any repair facility, and the shop performs the diagnosis and repair work.
- Star covers the cost of diagnosis and repair up to a set limit (currently $500 for most vehicles, $700 for heavier vehicles), and you pay any amount above that.
- After repairs are completed, you return to a smog station for a retest; if the vehicle passes, your registration can proceed.
- The program is free to join, but you must enroll before taking your vehicle to a Star shop.
How to enroll and find a participating repair shop
Enrollment happens through the California Bureau of Automotive Repair website. You will need your vehicle's VIN, license plate number, and the smog inspection report showing the failure. The Bureau's website has a searchable database of certified Star repair shops organized by county. Call ahead to confirm the shop is currently accepting Star cases, because some shops rotate in and out of the program or reach capacity during busy seasons.
When you contact a shop, have your smog report ready. The shop will tell you whether they can diagnose and repair your specific vehicle's emissions problem. Not every shop handles every type of vehicle—some specialize in certain makes or model years. Once you have chosen a shop and confirmed they are enrolled, you can schedule your appointment.
What Star covers and what you pay
Star reimburses repair shops for diagnosis and repair work up to a cap. For most passenger vehicles, that cap is $500. For heavier vehicles (trucks and SUVs over a certain weight), the cap is $700. The shop performs the work and bills the program directly for the covered amount. If the repair costs more than the cap, you pay the difference out of pocket.
The program covers only repairs needed to fix the emissions failure shown on your smog report. It does not cover routine maintenance, unrelated repairs, or work the shop recommends but that is not tied to the smog failure. Before the shop begins work, they should give you an estimate and explain which repairs are covered under Star and which are not.
The repair and retest process
Once you drop off your vehicle at the Star shop, the technicians will perform the diagnosis and any necessary repairs. Turnaround time varies—some shops complete work in a few days, others may take a week or longer depending on parts availability and workload. The shop will contact you when the work is done.
After repairs are finished, you take your vehicle back to a smog station for a retest. This retest is a separate transaction from the original inspection, and you will pay the standard smog check fee (which varies by county but is typically $30 to $50). If your vehicle passes the retest, the smog certificate is issued and your registration can proceed. If it fails again, you have the option to return to the Star shop for additional diagnosis, though the program's cost cap still applies.
When Star does not cover your vehicle
Star has age and mileage limits. Vehicles must be at least four model years old to be may be able to access. Very new cars are covered under manufacturer warranty and are not part of the Star program. Additionally, some vehicle types—such as motorcycles, off-road vehicles, and vehicles registered in other states—are not covered.
If your vehicle does not meet Star's criteria, you have two other options. You can pay for repairs out of pocket at any repair shop and then retest. Or, if your vehicle is very old or the repair cost is prohibitive, you may be able to request a Gross Polluter Abatement Program inspection, which can sometimes result in a waiver or alternative compliance path, though this depends on your specific situation and your county's rules.
What happens if repairs do not fix the problem
If your vehicle fails the retest after Star repairs, the program does not automatically pay for a second round of work. However, you can return to the Star shop and request additional diagnosis. The shop may identify a different or additional problem that was not caught in the first diagnosis. If that second repair is needed to pass smog, the shop can submit it to the program, and the cost cap applies to the total of all Star-covered work, not per visit.
If the vehicle continues to fail after multiple attempts, you may reach a point where the repair cost exceeds what Star will cover and what you can afford. At that stage, you would need to decide whether to pay out of pocket for additional repairs, seek a second opinion from another Star shop, or explore whether your vehicle qualifies for a waiver or retirement program through your county.
Differences between Star and a regular smog retest
A regular smog retest is what you do if you pay for repairs yourself at any shop and want to verify the vehicle now passes. You straightforward take it to any smog station, pay the retest fee, and if it passes, you are done. Star is different because it guarantees that a certified technician will diagnose the problem and perform repairs within a set cost limit before you pay for the retest.
The trade-off is that with Star, you must use a program-certified shop and follow the program's process. You cannot choose an independent mechanic you already trust unless they happen to be a Star participant. For many vehicle owners, especially those unfamiliar with emissions systems, Star's structured approach and cost cap make it worth the constraint.
Frequently Asked Questions
Can I use Star if my vehicle failed smog more than once?
Yes. Star covers any vehicle that has failed a smog inspection, regardless of how many times it has failed. Each time you fail, you can enroll in Star again and work with a repair shop to address the failure. The cost cap applies to each enrollment period.
What if the Star shop says my vehicle cannot be fixed?
If a Star shop determines the vehicle cannot be repaired or the repair is not feasible, they should document this and notify the Bureau. You may then be able to request a waiver or explore other options through your county's gross polluter program. Contact your local air quality management district for guidance.
Do I have to use the same Star shop if I fail the retest?
No. You can choose a different Star shop for a second attempt if you wish. However, the total cost cap still applies across all Star repairs for that vehicle, so a second shop will know what was already spent and what remains available.
Is there a time limit to complete Star repairs after I enroll?
Yes. You typically have 30 days from enrollment to have the repairs completed and the vehicle retested. If you do not complete the process within that window, you will need to re-enroll. Check your enrollment paperwork or contact the Bureau for the exact important date in your case.
What if I cannot afford the amount Star does not cover?
If the repair exceeds Star's cost cap and you cannot pay the difference, contact your county's air quality management district. Some counties have additional hardship programs or may offer guidance on other options, such as vehicle retirement programs for older vehicles.