---
title: "Clean Truck Check Deadlines 2026–2027 (Testing Twice, Then 4 Times a Year)"
description: "When is my Clean Truck Check test due? Deadlines follow your DMV registration date, every six months, with a 90-day testing window. OBD trucks move to…"
url: "https://ctcfinder.com/guide/deadlines-2026-2027/"
updated: "2026-10-30"
publisher: "CTC Finder (independent directory, not affiliated with CARB)"
---

# Clean Truck Check deadlines for 2026 and 2027

Updated 2026-10-30. Source: CTC Finder (https://ctcfinder.com/guide/deadlines-2026-2027/). Independent; not affiliated with CARB.

**Short answer:** In 2026 most heavy-duty trucks must pass a Clean Truck Check test **twice a year**. For California-registered trucks, the deadlines are the DMV registration expiration date and six months after it. You may test up to **90 days before** each deadline. Beginning **October 2027**, trucks with onboard diagnostics (OBD: 2013+ diesel and 2018+ alternative fuel) move to **four tests a year**. California-registered (non-commercial) motorhomes and agricultural vehicles stay at once a year.

> Some websites say quarterly testing starts January 1, 2027. CARB's FAQ and the regulation say **October 2027**.

## How your deadline is set

| Vehicle | Deadline schedule |
|---|---|
| Registered in California | DMV registration expiration date, then every six months |
| Registered outside California, or DMV-exempt (government) plates | Set by the last digit of the VIN (CARB's Table II) |
| California-registered motorhome | Once a year |
| Agricultural vehicle (farm business, used only in agriculture) | Once a year |

Your exact dates are shown in your CTC-VIS account. Check them there; CARB is the only official source.

## The 90-day testing window

CARB accepts a test submitted **no more than 90 days before** a compliance deadline. Example from CARB: for a February 1, 2025 deadline, testing could start November 3, 2024. A test inside the 90-day window covers that deadline; a test earlier than that does not count toward the next one, so plan your test dates.

> **Free reminders:** enter your next deadline on [CTC Finder reminders](https://ctcfinder.com/reminders/) and get an email 30 days and 7 days before each test is due.

## Timeline

| Date | What changed |
|---|---|
| January 1, 2023 | Regulation operative; roadside emissions screening (REMD) begins |
| October 1, 2023 | CTC-VIS opens for vehicle reporting and fees (initial deadline extended to January 31, 2024) |
| October 1, 2024 | Periodic emissions testing takes effect |
| January 1, 2025 | Deadlines from this date require a passing test |
| January 1, 2026 | Annual compliance fee rises to $32.13 per vehicle |
| January 1, 2027 | Annual compliance fee rises to $33.12 per vehicle |
| October 2027 | OBD vehicles move to four tests a year; non-OBD trucks stay twice a year |

## What quarterly testing means for fleets

Doubling the number of tests doubles the number of tester visits. For a fleet of 20 OBD trucks that is 80 tests a year instead of 40. Two ways fleets keep the cost down:

- **Mobile testers** who test many trucks per visit and offer fleet pricing. 2,543 businesses on CTC Finder offer mobile testing.
- **Telematics devices** certified by CARB (for example from Geotab, Samsara, Motive or Zonar) that a credentialed tester can use to upload OBD tests automatically.

## Missed a deadline?

Get the test done as soon as possible and check CTC-VIS for notices. Non-compliance can lead to a DMV registration hold, notices of violation and civil penalties. See [fines and penalties](https://ctcfinder.com/guide/fines-and-penalties/).

## Frequently asked questions

### How often does a truck need Clean Truck Check in 2026?

Twice a year for most heavy-duty diesel and alternative-fuel trucks; once a year for California-registered motorhomes and agricultural vehicles.

### When does Clean Truck Check go to 4 times a year?

CARB says OBD-equipped vehicles must test four times per year beginning October 2027. Older non-OBD trucks stay on twice-a-year smoke opacity tests.

### How early can I do my Clean Truck Check test?

Up to 90 days before the compliance deadline.

### Where do I find my Clean Truck Check due date?

Log in to CTC-VIS at cleantruckcheck.arb.ca.gov. For California trucks the deadlines are tied to the DMV registration expiration date.

### Is there a once-a-year option for low-mileage trucks?

Not under current rules. A 2026 bill (SB 1064) proposed annual testing for very low-mileage trucks, but the Governor vetoed it on September 20, 2026, so it is not law. Check CARB for updates.

## Sources

- CARB, [Requirements for vehicles subject to semi-annual compliance](https://ww2.arb.ca.gov/clean-truck-check-requirements-vehicles-subject-semi-annual-compliance)
- CARB, [Clean Truck Check FAQ](https://ww2.arb.ca.gov/resources/fact-sheets/clean-truck-check-faq-0)
- 13 CCR § 2196.1, [periodic testing requirements](https://www.law.cornell.edu/regulations/california/13-CCR-2196.1)
- CARB, [Annual vehicle compliance fee update for 2027](https://ww2.arb.ca.gov/annual-vehicle-compliance-fee-update-2027)
- CalMatters Digital Democracy, [SB 1064 bill history](https://calmatters.digitaldemocracy.org/bills/ca_202520260sb1064) (checked October 30, 2026)