In the current climate of increasing fiscal and clinical accountability, information is required about overall program effectiveness using clinical data. These requests present a challenge for programs utilizing single-subject data due to the use of highly individualized behavior plans and behavioral monitoring. Subsequently, the diversity of the client-specific programming does not yield data that are easily aggregated to inform program evaluations for effectiveness. This issue was addressed in one New England community mental health center providing school-based treatment for youth with significant emotional and behavioral disorders. After developing a behavior categorization system, behavior analysts reported client-specific behavioral progress into a main database. Aggregate data were then analyzed to provide information about overall program effectiveness using two reporting measures. The utility of aggregated single-subject data to inform clinical practice, clients, and program stakeholders is discussed.