Zero-Emission Vehicle Program
To meet California's health-based air quality standards and greenhouse gas emission reduction goals, the cars we drive and the fuel we use must get as close as possible to zero emission. The Zero-Emission Vehicle (ZEV) program is part of CARB's Advanced Clean Cars package of coordinated standards that controls smog-causing pollutants and greenhouse gas emissions of passenger vehicles in California.
The Zero-Emission Vehicle Regulation
The Zero-Emission Vehicle regulation is designed to achieve the state’s long-term emission reduction goals by increasing the requirements for zero-emission vehicles through both increased stringency of zero-emission vehicle sales and associated actions to support wide-scale adoption and use of zero-emission vehicles. Zero-emission vehicle requirements within ACC II are designed for new vehicles to reach 100% zero-emission and clean plug-in hybrid-electric in California by the 2035 model year. At present, zero-emission vehicle technologies are battery electric vehicles and hydrogen fuel cell electric vehicles. The Zero-Emission Vehicle regulation also includes innovative charging and zero-emission vehicle assurance measures, which include zero-emission vehicle warranty and durability requirements, serviceability, and battery labeling requirements, to help ensure consumers can successfully replace their conventional vehicles within California households with new or used zero-emission and plug-in hybrid electric vehicles that meet their needs for transportation and protect the emission benefits of the program. This will ensure that zero-emission vehicles permanently reduce and displace the emissions from conventional vehicles.
The California Air Resources Board (CARB) first adopted the Zero-Emission Vehicle requirement in 1990 as part of the Low-Emission Vehicle regulation. Over the last 30 years, the Zero-Emission Vehicle regulation has been modified to reflect the state of technology. Modifications adopted in 2012, along with the other two Advanced Clean Car Regulations, have set California on a path toward zero-emission vehicle commercialization enabling auto manufacturers to offer moderately priced zero-emission vehicles to consumers.
Zero-Emission Vehicles are Critical in California
Vehicles and transportation fuels are the dominant sources of carbon emissions in California. While California has made substantial improvements in air quality, the greater Los Angeles region and the San Joaquin Valley are classified by the United States Environmental Protection Agency as “extreme” ozone non-attainment areas, meaning the regions do not meet health-based air quality standards. The Zero-Emission Vehicle regulation is an integral part of California’s long-term solutions to improve air quality and reduce the state’s impact on climate change.
Zero-Emission Vehicles Dramatically Lower Smog and Greenhouse Gas Emissions
Zero-emission and near-zero emission vehicles such as battery-electric vehicles, hydrogen fuel cell vehicles and plug-in hybrid electric vehicles have ultra-low smog-forming and GHG pollutants, even over the life of a vehicle, which includes the vehicle’s fuel production emissions. Even compared to 2025 vehicles meeting the strictest smog and GHG fleet standards, zero-emission and plug-in hybrid-electric vehicles are significantly lower emitting and will be essential in order for the light-duty vehicle fleet to achieve long term emission reduction goals.
Manufacturers Subject to the Zero-Emission Vehicle Requirements
The Zero-Emission Vehicle Regulation requires large volume and intermediate volume vehicle manufacturers to bring to and/or operate in California a certain proportion of their sales as plug-in hybrid electric vehicles or zero-emission vehicles. BMW, Stellantis, Ford, General Motors, Honda, Hyundai, Kia, Mercedes, Nissan, Toyota, and Volkswagen must comply with the new requirements. Six smaller manufacturers (Jaguar Land Rover, Mitsubishi, Mazda, Subaru, Tesla and Volvo) are also required to comply with the ZEV requirements but may meet their obligation with plug-in hybrids. Credits generated by these manufacturers are reported annually.
Zero-Emission Vehicle Credits
CARB releases annual credit bank balances each year, as well as the total number of vehicles produced for that model year and the total number of zero-emission vehicles and plug-in hybrids.
Other States Have Adopted the Zero-Emission Vehicle Regulation
Other states have the ability to adopt California’s standards through Section 177 of the Clean Air Act, hence why they are often called the Section 177 states. See the latest states that have adopted the ZEV regulation.
Timeline of Regulatory Activities
|The Advanced Clean Cars II regulations were adopted in 2022, imposing the next level of low-emission and zero-emission vehicle standards for model years 2026-2035 that contribute to meeting federal ambient air quality ozone standards and California’s carbon neutrality targets.
|In March 2017 CARB staff presented the Board with the results of CARB's Midterm Review. In addition, staff already provided yearly status updates to the Board since the ACC regulations were first adopted in January 2012.
2015 Regulatory Activities | The 2015 modifications were developed to ensure that any additional ZEV credits awarded to fast refueling ZEVs were awarded on a one-to-one basis. The proposed rulemaking action was withdrawn on December 1, 2015.
2014 Regulatory Activities | The 2014 amendments provided greater flexibility to intermediate volume manufacturers in complying with their ZEV credit obligations, while still maintaining the Board’s commitment to a strengthened ZEV regulation. On October 12, 2015, Office of Administrative Law (OAL) approved amendments to the ZEV regulation that were adopted by the Board on May 21, 2015. The rulemaking became effective on January 1, 2016.
2013 Regulatory Activities | Staff proposed minor modifications for the ZEV regulation to include clarifying the Section 177 state optional compliance path provision, defining how caps apply to a auto manufacturer's requirement, and excluding battery swapping as a "fast refueling" technology. OAL approved the 2013 rulemaking and filed it with the Secretary of State on July 10, 2014. The rulemaking became effective the same day.
2010 - 2012
2010-2012 Regulatory Activities | The Board adopted regulatory changes to the ZEV program in 2012 that substantially increased and simplified requirements for 2018 and subsequent model years. California's Low-Emission Vehicle (LEV) regulations were amended, known as LEV III, to increase the stringency of tailpipe and greenhouse gas emission standards for new passenger vehicles. The 2012 modifications combined the control of smog-causing pollutants and greenhouse gas emissions into a single coordinated package of standards called Advanced Clean Cars. OAL approved the 2012 rulemaking and filed it with the Secretary of State on August 7, 2012. The regulation became effective the same day.
2009 ZEV Program Review | Staff went to the Board in December 2009 per Resolution 08-23. The Board directed staff to review the ZEV regulation, keeping in mind California’s long-term air quality and greenhouse gas (GHG) emission reduction goals. Staff held a 2009 ZEV Technology Symposium to learn about the status of ZEV technologies, and investigated infrastructure as part of the 2009 ZEV program review. (Documents available by request)
2008 Regulatory Activities | Staff went to the Board in early 2007 with the information gathered from the 2006 ZEV Technology Symposium as well as the report from the Independent Expert Review Panel. The Board determined that staff should recommend changes to the regulation for the 2009 and subsequent model years. The Board approved modifications to the regulation at the March 27, 2008 hearing. The Board also directed staff to redesign the ZEV program so it would affect the 2015 and subsequent model years. OAL approved the final 2008 rulemaking and filed it with the Secretary of State on March 18, 2009. The regulation became effective on April 17, 2009.
CARB held a technology symposium in 2006 and an Independent Expert Review Panel submitted their report on the status of all ZEV technologies. (Documents available by request)
2003 Regulatory Activities | Due to a lawsuit filed against the Board in January 2002, a federal district judge issued a preliminary injunction that prohibited the Board from enforcing the 2001 ZEV amendments with respect to the sale of new motor vehicles in model years 2003 or 2004. In order to address the preliminary injunction and better align the program requirements with the status of technology development, staff proposed additional modifications to the ZEV regulation in March 2003. Once the Board adopted the 2003 amendments to the ZEV regulation, the parties to the lawsuits agreed to end the litigation. On February 25, 2004, the Final Regulation Order and Supplement to the Final Regulation Order were approved by OAL and filed with the Secretary of State. The amendments become operative March 26, 2004.
Application of Early Introduction Multipliers to ZEVs - Rescission of November 21, 2002 Letter:
2001 ZEV Program Rulemaking | 2001 ZEV Infrastructure Rulemaking | The challenge at this time was to maintain progress toward commercialization of ZEVs, while recognizing constraints due to cost, lead-time and technical challenges. The 2001 ZEV rulemaking modifications allowed large auto manufacturers to meet their ZEV requirement with 2 percent pure ZEVs, 2 percent Advanced Technology PZEVs and 6 percent PZEVs. On May 24, 2002, OAL approved the 2001 regulatory amendments as set forth in the Final Regulation Order adopted April 12, 2002. In addition, the 2001 rulemaking on the amendments to the ZEV regulation regarding treatment of majority-owned small or intermediate volume auto manufacturers and infrastructure standardization was approved by OAL and filed with the Secretary of State on June 24, 2002, effective on July 24, 2002.
2000 ZEV Program Review | As part of the biennial review in 2000, staff was directed to review the regulation and propose appropriate modifications to address issues of ZEV availability, market demand, cost and incentives that would assure successful penetration of ZEVs into the market.
The ZEV mandate was adjusted again as part of the biennial review in 1998 to allow partial ZEV (PZEV) credits for extremely clean vehicles that were not pure ZEVs. The underlying goal never changed. California remained committed to seeing increasing numbers of ZEVs in the vehicle fleet. The challenge was determining how to reach this goal.
1996 ZEV Program Rulemaking | As part of the biennial review, the ZEV mandate was adjusted in 1996 to eliminate the “ramp up” years, but left in place the 10 percent ZEV requirement for 2003. The amendments were approved by the California Office of Administrative Law (OAL) on January 3, 1997, and became effective the same date.
Zero-Emission Vehicle (ZEV) Program | When CARB first adopted the Low Emission Vehicle regulation in 1990, it was noted that 10 percent of new vehicle sales would need to be zero-emission in order to meet tailpipe standards. Quickly, it became its own requirement. At that time, the Board required that in 1998, 2 percent of the vehicles that large auto manufacturers produced for sale in California had to be ZEVs, increasing to 5 percent in 2001 and 10 percent in 2003. When the ZEV requirement was adopted, the Board acknowledged that many issues would need to be addressed prior to the implementation date. The Board committed to biennial reviews of the program to provide a forum for the necessary policy discussions. The ZEV regulation has been modified several times over the years to reflect the state of technology.
Manufacturers Advisory Correspondence (MAC) 2006-02 for fast refueling capability criterion and advanced technology demonstration applications is available by request.