This report is meant to provide a snapshot of Massachusetts’ adult population prior to the implementation of new health reform legislation in the state. Using survey responses obtained in Fall 2006 as the Bay State began implementing a landmark effort to bring near-universal health coverage to its population, this report serves as the baseline for an on-going study of the effects of the reform efforts on Massachusetts’ working-aged adult population. We focus on the overall adult population aged 18 to 64 years old in Massachusetts, as well as those targeted by specific elements of the state’s reform efforts, including uninsured adults and adults with family income less than 100% of the federal poverty level (FPL), between 100% and 300% FPL, and between 300% and 500% FPL. We describe their insurance coverage and health care experiences in the period prior to the full implementation of the major health reform provisions. The goal of this report is to provide information to support Massachusetts’ efforts to implement the health care reforms. In subsequent work, we will document changes in insurance coverage and health care experiences as Massachusetts fully implements its health reform initiative.