This study explored the mechanisms at play as new family counselors are learning to apply a systems approach. A qualitative case study was used to investigate the experiences of nine family counseling interns over two semesters of internship through the lens of constructive developmental theory. The findings extend our understanding by providing students' accounts of the ways by which disequilibrium preceded development when accommodation was stimulated, and the outcomes when assimilation occurred. It also generated data about positive emotional response to clients that is new and intriguing and which may impact developmental growth. Implications for counselor education that incorporate developmental considerations are presented.