Activities and outcomes of a project to assist South Burlington High School (Vermont) special education students in mastering state-mandated basic competencies are described. The Interactive Model for Professional Action and Change for Teachers (IMPACT), which was conducted in cooperation with the University of Vermont, was designed to provide teacher support services and staff development activities, to develop monitoring systems to assess student competencies, and to disseminate improved special education and teacher support service systems to other Vermont schools. An overview is presented of the monitoring system, teacher support services (workshops, courses, team teaching), department heads' reactions to team teaching, and dissemination activities. In addition, a 1-year longitudinal study of 87 special education students and their peers is summarized, including their performance on standardized tests, grade point averages, absentee and dropout rates, and overall basic competencies performance. Efforts to measure the effects of the program on teachers through 44 observations of six teachers are also discussed. Lastly, information is provided on teachers interviewed, interview procedures, and results of evaluating training delivery modes. (SEW)