This paper, sponsored by the American Council for an Energy-Efficient Economy, reviews a number of energy efficiency financing programs that have been implemented in a number of States over the last several years. While a number of these programs have many years of experience and have issued thousands of loans, this market has yet to come to scale. Quantitative research analysis of both residential and commercial data includes: participation rates, loan sizes, terms, energy savings, and funding sources. Recommendations are provided. This report is a first step at scaling up energy efficiency financing.