This study assesses the impact of the Inflation Reduction Act (IRA) on electrification rates for light-duty and heavy-duty vehicle sales in the United States through 2035. By 2030, electric vehicle sales shares are estimated to range from 48 percent to 61 percent in the light-duty sector, increasing to 56 percent to 67 percent by 2032, the final year of the IRA tax credits. For heavy-duty, zero-emission vehicle sales shares are estimated to range from 39 percent to 48 percent by 2030 and from 44 percent to 52 percent by 2032. With the IRA, the U.S. Environmental Protection Agency can set more stringent vehicle greenhouse gas standards than would have been possible otherwise, at lower cost and higher benefit to consumers and manufacturers.