On April 12, 2023, EPA announced a proposal for new multipollutant emissions standards to further reduce harmful air pollutant emissions from light-duty passenger cars and light trucks and Class 2b and 3 vehicles (‘‘medium-duty vehicles’’ or MDVs) under its authority in section 202(a) of the Clean Air Act (CAA), 42 U.S.C. 7521(a), starting with model year 2027. The proposal builds upon EPA’s final standards for federal greenhouse gas emissions standards for passenger cars and light trucks for model years 2023 through 2026. The proposed standards would result in significant reductions in emissions of criteria pollutants, GHGs, and air toxics, resulting in significant benefits for public health and welfare. EPA also estimates that the proposal would result in reduced vehicle operating costs for consumers. The proposed standards would be phased in over model years 2027 through 2032. EPA conducted outreach with a wide range of interested stakeholders to gather input which was considered in developing the proposal, and will continue to engage with the public and all interested stakeholders as part of our regulatory development process as we develop the final rule.