Like most US transportation sectors, public transit is transitioning to zero-emission vehicles. This presentation will provide a breakdown of the state of the zero-emission bus (ZEB) industry and share best practices for deploying zero-emission buses. The Center for Transportation and the Environment (CTE) has collected US ZEB cumulative awards and sales data as well as product offerings available from bus manufacturers in the ZEB space. The results show a ten-fold increase in ZEB annual awards and sales from 2009 to 2017, with battery electric buses now making up about 6% of annual transit bus purchases. Product offerings by battery electric bus manufacturers show an increase in battery capacity and nominal range as newer models are unveiled, with vendor reported ranges averaging 200 miles. ZEBs include both battery electric and fuel cell electric technologies, with fuel cell electric buses offering ranges and refueling operations more similar to conventional bus technologies. Thus, best practices for deployment of a battery electric bus revolve around determination of expected real range in a given application and planning route service and charging operations to fit this range. Best practices for both ZEB technologies include evaluating infrastructure costs at scale. On-board energy storage capacity and nominal ranges for all ZEBs are expected to increase and improve over time. CTE is presently working with more than 60 transit agencies purchasing and deploying ZEBs.