This paper on staff development proposes one dimension of the Concerns-Based Adoption Model (CBAM), Stages of Concern, as a diagnostic tool for use by counselors, administrators, staff developers and other change facilitators who are responsible for the timing and delivery of staff development experiences. A rationale for staff development, the necessity of organizational change, and the role of change facilitators are discussed in an initial section. The CBAM model, which proposes concepts and techniques for assessing individuals' concerns about innovation, is described and the seven stages of concern are defined, i.e., refocusing, collaboration, consequences, management, personal, informational, and awareness. The 35-item Concerns Based Questionnaire is described, and the development of individuals' stages of concern is discussed. Levels of intervention corresponding to the stages of concern, with specific tactics and strategies, are proposed. Finally, the role of counselors in staff development using the Stage of Concern model is discussed. (MCF)