California Air Resources Board

Until January 1, 2030, High Priority and Federal Fleets and State and Local Government Agency Fleets may opt-in to the ZEV Milestones Option and meet zero-emissions vehicle (ZEV) targets as a percentage of their California fleets, as an alternative compliance option to the Model Year Schedule. This option allows for phasing ZEVs into the fleet between 2025 and 2042, depending on the type of vehicle and its usage. If choosing this option, starting January 1, 2025, fleet owners must continuously meet or exceed the ZEV Fleet Milestone percentage requirements, shown in Table A, for their California fleets. The California fleet includes vehicles operated in California by a fleet owner or controlling party during a calendar year and includes vehicles under common ownership or control. The ZEV Fleet Milestone percentages must be maintained each year until the next compliance milestone; for example, from January 1, 2025, until December 31, 2027, at least 10 percent of Milestone Group 1 vehicles in the California fleet must be ZEVs.

Please note that if a vehicle is operated in California at any time during a calendar year, it must be included in the California fleet when determining compliance for that calendar year. Vehicles that are sold or scrapped will reduce the California fleet size for purposes of the Milestones calculation at the time of selling or scrapping. However, transferring a vehicle out of state without selling or scrapping it would still count as part of the California fleet size for the entire calendar year the vehicle had operated in California.

Table A: ZEV Fleet Milestones by Milestone Group and Year

How do we calculate the number of ZEVs we must have?

The annual ZEV Fleet Milestone is calculated by counting the vehicles in the California fleet for each of the three Milestone Groups listed in Table A, then multiplying the number of vehicles in each Milestone Group by the ZEV percentage requirement for that year. Here is an example calculation for a fleet for the calendar year 2030. For this example, the California fleet consists of 100 Group 1 vehicles, 50 Group 2 vehicles, and 30 Group 3 vehicles:

Milestone Group 1: 100 vehicles x 25% = 25 ZEVs

Milestone Group 2: 50 vehicles x 25% = 12.5 ZEVs

Milestone Group 3: 30 vehicles x 10% = 3 ZEVs

Total ZEV Fleet Milestone = 40.5 ZEVs, which rounds up to 41 ZEVs needed that year.

The following additional example shows how a fleet might change over time.

Will any ZEV count toward compliance?

A ZEV from any Milestone Group can count toward the fleet’s ZEV Fleet Milestone requirement. In the first example, the fleet might choose to have 30 ZEV vans, 10 ZEV work trucks, and 1 ZEV sleeper cab tractor in 2030. In the second example, the total in the bottom row is what CARB considers for compliance purposes. Any ZEV may count toward this total (e.g. pickups, yard trucks, box trucks, tractors, or any combination of any vehicles from these groups) as long as they are vehicles within the scope of the regulation (typically gross vehicle weight rating 8,500+ lbs.; light-duty cars would not count). 

Can fleets using this option still add internal combustion engine vehicles to the California Fleet?

Any new internal combustion engine (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. Please see Internal Combustion Engine Purchase Requirements.

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.