In the fifth edition of ACEEE’s State Energy Efficiency Scorecard, we present a comprehensive ranking of the states based on an array of metrics that capture best practices and recognize leadership in energy efficiency policy and program implementation. The Scorecard benchmarks progress and provides a roadmap for states to advance energy efficiency in the residential, commercial, industrial, and transportation sectors. A new, diverse set of states has followed a group of leading states by adopting significant energy efficiency policies, which will lead to innovative and effective programs. Nonetheless, tremendous potential remains for energy efficiency savings in all of the states should motivate decision-makers to advance energy efficiency. Cost-effective investment in energy efficiency now will be critical for the success of local, state, and national economies in the future.