This report updates ACEEE's 2013 assessment of multifamily energy efficiency programs in US metropolitan areas with the most multifamily households. Using housing, policy, and utility-sector data from 2014 and 2015, this report documents how these programs have changed in the context of dynamic housing markets and statewide policy environments. The report also offers an analysis of the number, spending, offerings, and targeted participants of current programs and their potential for further expansion.