CARB Clean Truck Check Compliance Begins Jan. 1
Starting January 2024, all trucks driving in California will need proof of compliance with CARB’s Clean Truck Check to continue operating in the state. Operating in California without registration in the compliance database could result in violations from CARB and/or the California Highway Patrol.

Remote Emissions Monitoring Devices monitor the exhaust emissions of passing heavy-duty vehicles and flag potential high emitters.
Photo: CARB
Beginning on January 1, 2024, all trucks operating in California will need proof of compliance with California Air Resources Board (CARB) regulations to continue operating in the state. Vehicles must be registered in the Clean Truck Check database by Dec. 31.
Clean Truck Check, formerly known as the Heavy-Duty Inspection and Maintenance Program, was approved by CARB in 2021. CARB said the program ensures heavy-duty vehicles operating in California are well-maintained and repaired quickly when needed to reduce emissions and improve public health statewide, especially in disadvantaged communities disproportionately impacted by air pollution.
It also provides a level playing field for the businesses that operate these vehicles as it applies to both in-state and out-of-state registered heavy-duty vehicles, according to CARB.
The program includes nearly all non-gasoline vehicles with a gross vehicle weight rating over 14,000 pounds that operate in California. This includes public vehicles, trucks, buses, personal vehicles, California-registered motorhomes, single-vehicle fleets, and vehicles registered outside of California (not including motorhomes).
Clean Truck Check is being implemented in three phases.

Clean Truck Check rolls out starting in 2023 and into 2024.
Source: CARB
Phase 1 of Clean Truck Check
This initial phase, which started Jan. 1, began with the deployment of Remote Emissions Monitoring Devices (REMD).
REMDs monitor the exhaust emissions of passing heavy-duty vehicles and flag potential high emitters that may receive a Notice to Submit to Testing (NST).
NST’s require vehicle owners to submit a passing compliance test to CARB after any necessary emissions-related repairs are made, within 30 days of receipt of the notice. Failure to comply and remedy emissions-related concerns could result in DMV registration holds and/or removal from the compliance database.
Phase 2 of Clean Truck Check
This phase, which started Oct. 1, requires vehicle owners who are subject to the program to enter their vehicles in CARB’s Clean Truck Check database and pay an initial annual compliance fee of $30 dollars per vehicle by December 31.
Phase 2 also includes freight contractor, broker, and applicable freight facility requirements for hiring compliant fleets, allowing access to the facility, and record keeping.
Starting January 2024, all trucks driving in California will need proof of compliance with these requirements to continue operating in the state. Operating in California without registration in the compliance database could result in violations from CARB and/or the California Highway Patrol.
Phase 3 of Clean Truck Check
Phase 3 of Clean Truck Check requires heavy-duty vehicle owners to conduct periodic emissions testing on their vehicles.
This is similar to California’s Smog Check program for cars, according to CARB.
Periodic testing begins in 2024 and applies to all compliance deadlines after July 1, 2024.
Compliant tests may be submitted as early as April 2024. Periodic testing initially will be required twice per year for nearly all vehicles in the program.
Agricultural vehicles and California-registered motorhomes are required to test once annually. Testing requirements vary based on whether the vehicle is equipped with onboard diagnostics (OBD).

CARB reports Clean Truck Check will save more than 7,500 lives and prevent 2,500 hospital visits.
Source: CARB
For California-registered vehicles, the compliance testing deadlines are linked to each vehicle’s DMV registration expiration/renewal date.
For vehicles registered outside of California and for vehicles exempt from DMV registration requirements, compliance deadlines are based on the last number of a vehicle’s VIN.
Passing test results may be submitted up to 90 days before a compliance deadline. Testing should be performed in a timely manner to avoid penalties and possible DMV registration holds.

A truck passes an emissions monitoring station in California.
Photo: CARB
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