We analyse US Inflation Reduction Act (IRA) incentives for electric vehicle battery technology and supply chain decisions. We find that the total value of available credits exceeds estimated battery production costs, but qualifying for all available credits is difficult. IRA cell and module credits alone bring estimated US battery production costs in line with China. In contrast, IRA material extraction and processing credits are modest. IRA’s end-user purchase credits are restricted to electric vehicles whose battery supply chains exclude foreign entities of concern, including China. This incentivizes diversification of the entire supply chain, but leasing avoids these restrictions. Lithium iron phosphate batteries have potential to more easily reduce supply chain vulnerabilities and qualify for incentives, but they have smaller total available incentives than nickel/cobalt-based batteries. Overall, the IRA primarily incentivizes downstream battery manufacturing diversification, whereas upstream supply implications depend on automaker responses to foreign entities of concern and leasing rules.