The production of Renewable Natural Gas (RNG) from organic waste for use as a vehicle fuel is an emerging strategy that businesses, states, and municipalities in the United States are pursuing to make use of waste-derived methane and lower the carbon footprint of vehicle fleets. This working paper explores RNG’s potential as a climate-change strategy in the U.S., including the conditions under which it can achieve large greenhouse gas (GHG) emissions reductions compared to fossil fuels used to power vehicles.