Over half of the states now embrace specific energy efficiency savings requirements, known as Energy Efficiency Resource Standards (EERS). An EERS requires utilities (or related organizations in states where the programs are administered by non-utility entities) to save a certain amount of energy each year, typically expressed as a percentage of annual retail energy sales or as specific energy savings amounts set over a long-term period. This report, Energy Efficiency Resource Standards: A Progress Report on State Experience, includes legislative and regulatory background for every state where an EERS policy has been in place for over two years and examines the progress these states have made achieving their goals. Tracking actual energy savings and comparing these results with the required targets, the analysis develops a comprehensive portrait of the performance of twenty states, noting important trends influencing the outcomes thus far. Overall, the performance of states in comparison to the targets set in EERS policies has been encouraging; most states are meeting or are on track to meet energy savings goals. The report finds that states’ performance meeting energy savings targets is driven by issues such as the clarity and appropriateness of the regulatory framework, the length of time allowed for program administrators to ramp-up programs, and the overall commitment of all parties to invest the proper resources to meet targets. States must overcome these barriers in order to successfully meet EERS targets and states considering the adoption of an EERS should carefully consider these issues in the policymaking process.