The document summarizes research exploring the air pollution and emissions benefits of electrifying medium- and heavy-duty vehicles using the EPAUS9rT-TIMES energy system model. The research finds that adopting a target of 100% zero-emission medium- and heavy-duty vehicles by 2050 results in net carbon dioxide reductions despite increasing electricity demand. It also finds marginal reductions in other air pollutants from the transportation sector, though reductions are smaller than declines seen in the power and industrial sectors. A carbon tax can further reduce emissions but is not necessary for the zero-emissions vehicle target to provide benefits.