The Concerns-Based Adoption Model (CBAM) has been designed to describe change as it affects individuals and to prompt more successful change efforts. CBAM views the teacher as the focal point in school improvement efforts, yet also acknowledges social and organizational influences. This paper describes the application of the model to a curriculum implementation effort in revising the science curriculum in grades three to six in the 80 elementary schools of Jefferson County (Colorado). The design for curriculum implementation was based on an understanding of teachers' concerns and how they change over time. Two CBAM measures of teacher change were used: Stages of Concern About the Innovation and Levels of Use of the Innovation. These measures and their application to a representative sample of teachers are explained. Some of the study's results have direct implications for facilitators of change efforts. First, that the actions taken by building principals to support or inhibit a change effort have direct effect on how teachers feel about and ultimately use a new program. Secondly, implementing an innovation takes more than one year. Change facilitators and policymakers should set realistic expectations for themselves, teachers, administrators, and evaluators. (Author/MLF)