The effects of functional communication training on the generalized reduction of problem behavior with three 4- to 5-year-old children with autism and problem behavior were evaluated. Participants were assessed in primary teaching settings and in three secondary, generalization settings. Through baseline analysis, lower effort interventions in the secondary settings were documented as ineffective when implemented alone. Higher effort interventions incorporating functional communication training were documented within a multiple baseline design to reduce problem behavior in the primary setting, but not in secondary settings until the lower effort interventions were re-introduced. Results demonstrate the need for trans-situational interventions based on a common functional assessment hypothesis across settings and including intensive interventions that enhance the effects of lower intensity interventions.