The Milbank Memorial Fund's Multi-State Collaborative (MC) is a working group of 18 states and regions actively engaged in multi-payer primary care transformation through the implementation of patient-centered medical home (PCMH) programs. These innovative efforts include payment reform and enhanced multidisciplinary support services. Each of the MC programs were early adopters of multi-payer primary care -- their leaders made investments of time and resources before knowing what the outcomes would be. Assessing their own programs has been an important component of the MC members' work -- and each MC member has been conducting an evaluation of the effectiveness of its PCMH program. As the programs developed, they grew in complexity -- as did the methods needed to evaluate them. The challenge was to ensure that promising results were not missed -- or impacts overstated. In order to understand the extent to which MC PCMH programs are improving outcomes for a core set of key health care utilization and spending measures, the Fund asked Mathematica Policy Research to develop this report. It analyzes eight of the 18 MC member evaluations in order to assess the strength of the evidence being reported and to provide a foundation for learning how to strengthen future advanced primary care evaluations.