The main purpose of the present report is to determine whether and how gambling attitudes, gambling behavior, and problem gambling prevalence changed in Massachusetts following the introduction of casinos. Results from the Follow-up General Population Survey (FGPS) are directly comparable to survey data collected in Massachusetts in 2013 and 2014, before any of the casinos had opened. In addition to these overall assessments, the report addresses the question of whether the demographic and behavioral patterns of gambling and problem gambling prevalence changed in Massachusetts between 2013 and 2021.