This paper examines how teachers' expectations of their ability to produce student learning varies within teaching assignments. In the study described here, 359 teachers in 9 restructuring secondary schools in 1 district estimated their ability to perform common teaching tasks in 4 of the courses they expected to teach in the coming school year. Results show that teacher efficacy was lower for courses outside the teacher's subject. The findings indicate that teacher efficacy is threatened when teachers move away from their home departments, either by teaching a course outside their subject or by facilitating curriculum activities that cross departmental lines. The effects of teaching outside one's area were greater than the effects of track and grade, two course characteristics that have been linked to teacher efficacy in previous research. The study also found that teacher efficacy was influenced by teachers' leadership roles. Teachers who were expected to promote student learning across subjects had lower teacher efficacy than teachers in traditional positions of added responsibility (department heads) and teachers who were not in leadership positions. It is suggested that if reform is to succeed, reformers need to create coping structures and strategies for enabling teachers to move out of departments. (Contains 65 references and 6 tables.) (RJM)