California Air Resources Board

What are high priority and federal fleets and what vehicles are affected by this regulation?

High priority fleets are entities that own, operate, or direct the operation of at least one vehicle in California, and that have either $50 million or more in gross annual revenue, or that own, operate, or direct the operation of a total of 50 or more vehicles. Federal government agencies that own, operate, or direct the operation of at least one vehicle in California are also subject to this regulation. References in this document to high priority fleets will also apply to federal government fleets, because both are covered by the same requirements. Vehicles affected are those with a gross vehicle weight rating greater than 8,500 pounds, light-duty package delivery vehicles, or off-road yard tractors that are operated in California.

What are the compliance and reporting requirements for high priority fleets?

The first compliance requirement is to submit a compliance report--the initial report must be submitted by February 1, 2024. Fleet owners must annually submit a compliance report for their California fleet, as it is composed as of January 1 of the corresponding calendar year. The annual reporting period is during the month of January and reports must be submitted no later than February 1 of each year until February 1, 2045, through the Truck Regulation Upload, Compliance, and Reporting System. For further information, see the Reporting Requirements Overview. Fleet owners must keep records of reported information and required documentation for a period of at least five years. In addition to reporting, high priority fleets must comply with the Model Year Schedule OR may choose to use the ZEV Milestones Option to phase zero-emissions vehicles (ZEV) into their fleets.

How do I comply with the Model Year Schedule?

Beginning January 1, 2024, fleet owners complying with the Model Year Schedule may add only ZEVs to their California fleet. The California fleet includes those vehicles operated in California by a fleet owner or controlling party during a calendar year and includes those vehicles under common ownership or control. Beginning January 1, 2025, fleet owners must begin removing internal combustion engine (ICE) vehicles from their California fleets by January 1 of the calendar year after those vehicles exceed their minimum useful life mileage thresholds, or January 1 of the calendar year the engine model year is 18 years old or older, whichever occurs first. Starting in 2024, any new ICE vehicle, 2024 or newer, added to the California fleet must have an engine certified to applicable California emissions standards and emissions related requirements, and any used ICE vehicle added to the California fleet must have a 2010 or newer model year engine. Visit Internal Combustion Engine Purchase Requirements fact sheet for additional information.

How do I comply with the ZEV Milestones Option?

Until January 1, 2030, instead of the Model Year Schedule, fleet owners may elect to meet ZEV targets as a percentage of their California fleet starting with vehicle types that are most suitable for electrification. This option allows for phasing ZEVs into the fleet between 2025 and 2042 based on the vehicle type. When opting into the ZEV Milestones Option, the fleet owner must report this intention. For more information on this option, visit ZEV Milestone Option.

Can a fleet switch between compliance options?

Until January 1, 2030, fleet owners may switch between the compliance options if their California fleet is in compliance with both the requirements of the currently elected compliance option and the desired alternative compliance option. They must also be in compliance with the desired alternative compliance option from January 1, 2024 through the date the option is switched.

Are any vehicles exempt from the requirements?

School buses, military tactical vehicles, vehicles awaiting sale, emergency vehicles, historical vehicles, dedicated snow removal vehicles, two-engine vehicles, heavy cranes, and vehicles in a test fleet are exempt from the regulation. See Section 2015(c) of the Final Regulation Order for further information regarding each of these and other exempt vehicle types.

Can a fleet get exemptions or extensions?

A fleet owner may qualify for one or more exemptions and extensions by requesting and receiving approval from CARB, though some extensions like the Backup Vehicle Exemption and adding vehicles that appear on the ZEV Purchase Exemption List do not require pre‑approval, but do require reporting. Any exemptions or extensions granted to a fleet owner are not transferrable to another fleet owner. Fleet owners requesting or using any exemptions or extensions must meet applicable reporting and recordkeeping requirements for each exemption or extension. Further details on these exemptions and extensions can be found on the Exemptions and Extensions page.

This document is provided to assist regulated entities in complying with the Advanced Clean Fleets regulation. In the event any discrepancy exists between this document and the Advanced Clean Fleets regulation, the regulatory text of the Advanced Clean Fleets regulation applies.