Six organizational conditions of schools, identified from a review of the social-psychological literature on job design, are found to affect the job commitment of 1,213 teachers from 78 elementary schools throughout Tennessee. The authors divide organizational qualities into those that impinge on the tasks of defining boundaries and implementing the professional teaching task and those that directly affect the core instructional role of the teacher. They find that novice teachers' commitment is influenced more by organizational supports for the management of boundary issues, while experienced teachers are influenced more by organizational qualities that affect the core instructional tasks. They also find that midcareer teachers have a lower commitment to their jobs and place a greater emphasis on task autonomy than do either novices or veterans.