When did Clean Truck Check start?

CARB phased in Clean Truck Check (HD I/M) over several years with registration, fee collection, and testing requirements rolling out by vehicle population. Exact milestone dates are documented in CARB board materials and program FAQs on arb.ca.gov.

When does quarterly testing begin?

CARB has announced a path toward quarterly testing for many heavy-duty fleets, with expanded frequency targeting October 2027 for broad implementation. Your specific VIN schedule appears in CTC-VIS—program-wide announcements on arb.ca.gov explain phase-in by fleet size and vehicle type.

How do I know which timeline applies to my fleet?

Log in to CTC-VIS and review each VIN’s assigned testing frequency and open window. CARB may stagger requirements by registration date, fleet size, or vehicle category. Do not assume your neighbor fleet’s schedule matches yours.

Clean Truck Check compliance timeline

Clean Truck Check did not arrive overnight. CARB phased in registration, fees, and testing requirements over several years—and continues tightening frequency toward quarterly inspections for many operators by October 2027. Use this page for orientation; use CTC-VIS for your actual due dates.

Program milestones (high level)

CARB developed the Heavy-Duty Inspection and Maintenance (HD I/M) program to address in-use diesel emissions from California’s freight sector. Key public milestones—board approvals, CTC-VIS launch, initial registration periods, and enforcement ramp-up—are chronicled in official CARB documents on arb.ca.gov. Third-party summaries may omit nuance or reflect outdated dates.

CTC-VIS becomes the system of record for registration, fees, and test results
Credentialed private testers perform OBD and opacity inspections statewide
Annual testing cycles assigned to registered VINs with multi-month compliance windows
Phase-in toward more frequent testing for applicable fleet categories

Annual today, quarterly tomorrow

Most operators currently see annual testing requirements in CTC-VIS. CARB’s published roadmap moves many fleets toward quarterly testing, with broad implementation targeted around October 2027. Increased frequency materially affects shop capacity, mobile tester availability, and annual compliance budgets—start planning before the rule change hits your VIN list.

Read our testing frequency guide and 2026 deadline calendar for operational planning templates. Confirm any announced dates on arb.ca.gov when building multi-year fleet budgets.

Your VIN-level timeline in CTC-VIS

Program-wide milestones matter for policy teams; dispatchers need VIN-level due windows. After registration, CTC-VIS displays each unit’s open testing period, required test type, fee status, and last pass/fail result. Export or screenshot these fields when building internal compliance calendars.

Build recurring reminders at 90, 60, and 30 days before each window closes. Pair calendar alerts with a weekly CTC-VIS review so newly acquired trucks do not slip through onboarding. Zurfex helps execute the testing step—search credentialed testers once your window opens.