Updates to CARB’s Advanced Clean Fleet Regulations

At a recent meeting, the California Air Resources Board (CARB) made notable changes to their Advanced Clean Fleet regulations. Actions throughout 2025 at the federal level limited the applicability of the ACF to state and local government fleets. Additionally, state legislation (AB 1594) in 2024 required CARB to provide flexibility in the ACF regulations to  public agency utilities that use highly specialized vehicles in carrying out their work. As a result of these two requirements, the board voted to:  

• Repeal their ability to enforce the ACF’ regulations on private and federal vehicle fleets. This was necessary as CARB was unable to secure a waiver from the federal government for these vehicles 
• Expand exemptions for public agency utility fleets, including allowing these fleets purchase of combustion engine vehicles when ZEVs are not available or do not meet the fleet’s needs. 
• Delay the existing 100% ZEV purchase requirement that applies to all remaining fleets from 2027 to 2030.  

However, we note that while CARB voted for this course of action, it did not have regulatory language drafted at the time they voted to make these changes. CSAC provided written and verbal comments at the Board meeting requesting additional modifications to the ACF regulations to assist counties. Meanwhile, polling conducted by the California Special Districts Association indicates that 70% of state voters support exempting a broader range of emergency vehicles from the ACF. CSAC will continue to advocate on behalf of counties as CARB continues to consider making changes to the ACF regulations.