If you run a heavy-duty vehicle in California and you are not sure what Clean Truck Check requires of you, this is the starting point. Who it covers, what you have to do, what it costs, and the dates that matter.
Clean Truck Check is the common name for California's Heavy-Duty Inspection and Maintenance (HD I/M) program, run by the California Air Resources Board. It came out of Senate Bill 210 in 2019, the Board approved the regulation in December 2021, and it phased in starting in 2023. The goal is to make sure heavy-duty emissions control systems keep working over a vehicle's life.
The program covers almost all diesel, alternative fuel, and hybrid vehicles with a gross vehicle weight rating over 14,000 lbs that operate on California public roads. That includes commercial and private vehicles, buses, and vehicles registered outside California when they operate in the state. A single owner-operator and a large fleet are subject to the same core rules.
There are three obligations, all handled through CARB's CTC-VIS portal.
| Obligation | Detail |
|---|---|
| Report | Register each subject vehicle in the CTC-VIS system. |
| Pay the annual fee | $32.13 per vehicle for 2026, effective January 1, 2026, by your compliance deadline. |
| Test | Submit a passing emissions test from a CARB-credentialed tester, no more than 90 days before your deadline. |
Most vehicles are on a semi-annual schedule, meaning a passing test twice a year. Starting October 1, 2027, vehicles equipped with on-board diagnostic systems move to four submissions per year. Your specific deadlines appear on your entity page in CTC-VIS.
Testing has to be performed by a CARB-credentialed tester and the results submitted to CARB. This is where a mobile tester helps a small fleet: rather than driving each truck to a shop, a credentialed tester comes to your yard, runs the test on-site, and submits the result. A failed test still counts as a completed test for reporting; you then handle repairs and a re-test.
The first consequence most operators feel is a DMV registration hold that blocks renewal until the vehicle passes. CARB also screens for high emitters with roadside monitoring and license plate readers, and a flagged vehicle gets 30 days to submit a passing test. Operating an uncertified or tampered vehicle carries a penalty of up to $37,500 per violation under California Health and Safety Code.
The cheapest path is the boring one: register your vehicles, pay the fee, and keep a passing test on file ahead of each deadline. The cost of staying current is small next to a grounded truck.
For your actual deadlines and status, use the CTC-VIS portal. For program questions, CARB's hotline is 1-866-634-3735. To check your federal carrier record, use FMCSA SAFER.
Sources: CARB Clean Truck Check program page · CARB Clean Truck Check FAQ · 2026 fee of $32.13 per vehicle · quarterly testing for OBD-equipped vehicles effective October 1, 2027. CarbAudit is an independent referral service and does not provide legal advice.
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