This study focused on therapist-counselor development. In-depth, semi-structured interviews with 100 participants served as the data-gathering method. Data from this study were first used to develop a stage model. Then, 20 themes of therapist-counselor development were extracted from the 120 pages of narrative stage data. The themes were extracted jointly by the two authors through a set of qualitative research procedures. These themes are described within the categories of primary characteristic themes, process descriptor themes, source of influence themes, and secondary characteristic themes. Professional development topics addressed include professional individuation, methods of renewal, conceptual orientation, measures of success, learning processes, boundary regulation, and impact of professional elders.