The electricity industry is evolving as changes in natural gas and coal prices, along with environmental regulations, dramatically shift the generation mix. Future trends in gas prices and costs of renewables are likely to continue moving the industry away from coal-fired generation and into lower-emitting sources such as natural gas and renewables. The U.S. Environmental Protection Agency’s Clean Power Plan (CPP) is likely to amplify these trends. The CPP rule regulates emissions from existing fossil generators and allows states to choose among an array of rate-based and mass-based goals. The analysis in this paper uses the electricity-dispatch component of the Nicholas Institute for Environmental Policy Solutions’ Dynamic Integrated Economy/Energy/Emissions Model to evaluate electricity industry trends and CPP impacts on the U.S. generation mix, emissions, and industry costs. Several coordinated approaches to the Clean Power Plan are considered, along with a range of uncoordinated “patchwork” choices by states. The model results indicate future industry trends are likely to make compliance with the Clean Power Plan relatively inexpensive; cost increases are likely to be on the order of 0.1% to 1.0%. Some external market conditions such as high gas prices could increase these costs, whereas low gas or renewables prices can achieve many of CPP goals without additional adjustments by the industry. However, policy costs can vary substantially across states, and may lead some of them to adopt a patchwork of policies that, although in their own best interests, could impose additional costs on neighboring states.