CARB Clean Truck Check Deadlines 2025-2026: What Northern California Truckers Need to Know

Through 2026, most heavy-duty diesel vehicles must pass a CARB Clean Truck Check twice a year, and beginning October 2027, OBD-equipped vehicles move to quarterly testing. Miss a deadline and CARB places a hold on your DMV registration until you test and pass.

Fast facts (2026)

• 2025-2026 frequency: Semi-annual (twice per year) for subject vehicles.
• October 2027 change: OBD-equipped vehicles (2013+ diesel, 2018+ alternative fuel) move to quarterly testing (four times per year). Non-commercial motorhomes and agricultural vehicles stay annual.
• 2026 compliance fee: $32.13 per vehicle, paid to CARB (up from $31.18 in 2025).
• Miss a deadline: DMV registration hold until compliance is confirmed.
• Look up your date: CARB Clean Truck Check portal at cleantruckcheck.arb.ca.gov.

Why deadlines matter

The CARB Clean Truck Check program requires periodic emissions testing for most heavy-duty diesel vehicles in California. When you miss your testing deadline, CARB notifies the DMV and a hold is placed on your vehicle registration. You cannot renew registration or legally operate the vehicle on California public roads until compliance is confirmed.

How testing frequency is determined

Your required frequency depends on your vehicle’s model year, engine model year, compliance history, and whether the vehicle has previously failed testing. Exact deadlines are assigned by VIN and registration type, so two trucks in the same fleet can carry different dates.

For current, vehicle-specific deadlines, register in the CARB Clean Truck Check portal at cleantruckcheck.arb.ca.gov. The portal shows your compliance status and upcoming deadlines.

What is changing: quarterly testing in October 2027

The most important change on the horizon: beginning October 2027, OBD-equipped vehicles will be required to test four times per year instead of twice. This applies to 2013 and newer diesel engines and 2018 and newer alternative-fuel engines. Non-commercial motorhomes and agricultural vehicles are exempt from the quarterly schedule and remain annual. If you run a modern OBD fleet, plan now for four testing windows a year starting in late 2027.

What to do before your deadline

Do not wait for a DMV hold notice to schedule testing. Book your test at least 2 to 4 weeks before your deadline to leave room for repairs if the vehicle fails its first test. If your truck does fail, here is exactly what to do next.

For Sacramento and Northern California operators, mobile testing is the fastest and most convenient option. We schedule same-day or next-day appointments across Sacramento, the Sacramento Region, and the SF Bay Area, and OBD results upload immediately so your compliance status updates without a waiting period.

Need help understanding your deadline? Call us at (916) 538-7777.