The purpose of this study was to refine, test, and demonstrate the applications of an instrument (the Community Adaptation Schedule) for assessing community adaptation within the psychosocial context defined by contemporary community mental health theorists and practitioners. Subsequent to formulating an operational definition of community adaptation via test construction, the new measure was administered to samples of mental health professionals, outpatients, and psychiatric hospital patients. The schedule was effective in producing significant differential patterns and scores for the study groups on most of the adaptation indices. Further, it showed high reliability, high predictive value in determining group membership, and a strong covariant relationship with a Social Activity Inventory, used as a validation measure.