The U.S. electricity sector is undergoing a period of rapid change. The U.S. Environmental Protection Agency’s Clean Power Plan (CPP), regulating carbon dioxide (CO2) from existing power plants, is a significant—but by no means the only—catalyst for the transitions underway in the sector. In this third and final note in the series on the CPP, the authors explore the energy market outcomes of the rule under two scenarios and discuss what factors could change the magnitude of these impacts.