Short answer: Your vehicle needs Clean Truck Check if it has a manufacturer's GVWR over 14,000 lbs, runs on diesel or an alternative fuel (natural gas, propane, hybrid diesel, etc.) and operates on California roads, wherever it is registered. Gasoline vehicles are not covered. Exempt: zero-emission vehicles, emergency vehicles, military tactical vehicles, historical vehicles, motorhomes registered outside California, vehicles under an experimental permit and new engines certified to the optional 0.01 g/bhp-hr NOx standard (2023–2027 only).
Quick check: does my vehicle need it?
| Question | If yes | If no |
|---|---|---|
| Is the manufacturer's GVWR over 14,000 lbs? | Keep going | Not covered |
| Does it run on gasoline only? | Not covered | Keep going |
| Is it zero-emission (battery-electric or hydrogen fuel cell)? | Exempt | Keep going |
| Does it ever operate on California public roads? | Covered | Not covered |
| Is it on CARB's exemption list (below)? | Exempt | Covered |
Use the GVWR on the door-jamb label, not the actual load or registered weight.
Covered vehicles
CARB says the program covers "nearly all diesel and alternative fuel heavy-duty vehicles" over 14,000 lbs GVWR, including:
- commercial trucks, tractors and buses, including hybrids;
- government vehicles (state, county, city and federal plates);
- transit buses and school buses;
- personal (non-commercial) vehicles in that weight class;
- out-of-state and out-of-country vehicles while operating in California, including trucks from Mexico and Canada;
- California-registered motorhomes (tested once a year);
- agricultural vehicles (tested once a year).
Exempt vehicles
CARB's overview fact sheet lists these exemptions:
| Exempt vehicle | Legal reference |
|---|---|
| Zero-emission vehicles | — |
| Military tactical vehicles | 13 CCR § 1905 |
| Emergency vehicles | Vehicle Code § 165 or Health and Safety Code § 1797.84 |
| Historical vehicles | Vehicle Code § 5004 |
| New engines certified to the optional 0.01 g/bhp-hr NOx standard | 2023–2027 only |
| Motorhomes registered outside California | — |
| Vehicles operating under an experimental permit | Health and Safety Code § 43014 |
There is no low-mileage exemption. SB 1064, which would have allowed once-a-year testing for trucks under 1,000 miles a year, was vetoed in September 2026. There is also no exemption for trucks that only occasionally enter California.
Special cases
Motorhomes and RVs
California-registered motorhomes over 14,000 lbs GVWR (diesel or alternative fuel) test once a year. Motorhomes registered in another state are exempt. A motorhome used commercially (not for recreation or emergency occupancy) follows the normal twice-a-year schedule. 2,007 of the testers we list say they test motorhomes.
Agricultural vehicles
A vehicle owned or operated by a farming business and used only in agricultural operations tests once a year. If it also hauls for hire, the normal schedule applies.
Pickups and medium-duty trucks
Most full-size pickups (including heavy-duty 3500 models) have a GVWR under 14,000 lbs and are not covered. Class 4 and up trucks (box trucks, dump trucks, bucket trucks) usually are, if they are diesel or alternative fuel.
Out-of-state trucks
Covered whenever they operate in California. Deadlines for non-California plates are set by the last digit of the VIN. EPA's January 2026 decision approved the rule into California's air plan only for in-state vehicles, but CARB says it still enforces the program for all vehicles. See out-of-state trucks.
What covered vehicles must do
- Be reported in CTC-VIS (how to register).
- Pay the annual fee ($32.13 in 2026, $33.12 in 2027).
- Pass a test by a CARB-credentialed tester before each deadline (find one).
- Clear any outstanding violations.
Sources
- CARB, Clean Truck Check overview fact sheet
- CARB, Clean Truck Check FAQ
- CARB, Agricultural vehicles and California motorhomes (annual)
- 13 CCR § 2195.1, definitions
- California Senate, SB 1064
Frequently asked questions
Do gasoline trucks need Clean Truck Check?
No. Clean Truck Check covers diesel and alternative-fuel vehicles over 14,000 lbs GVWR. Gasoline vehicles are not covered.
Are electric trucks exempt from Clean Truck Check?
Yes. Zero-emission vehicles are exempt.
Do school buses and government trucks need Clean Truck Check?
Yes. Government, transit and school vehicles over 14,000 lbs GVWR that are diesel or alternative fuel are covered. Government vehicles with DMV-exempt plates follow a VIN-based deadline schedule.
Is there an exemption for low-mileage trucks?
No. SB 1064 proposed once-a-year testing for trucks under 1,000 miles a year, but it was vetoed in September 2026.
Does Clean Truck Check apply to trucks from Mexico?
Yes. CARB says the program covers out-of-state and out-of-country vehicles when they operate in California.
CTC Finder is an independent directory and is not affiliated with CARB. Rules change; check CARB's Clean Truck Check pages for the official version.