This article provides a theoretic exploration of the microprocesses of clinician practice change in the context of adopting and implementing evidence-based treatments. The two most important internal clinician or microlevel factors involved in behavior change are identified as motivation and ability. The authors focus on factors related to motivation and present their own theory of the cognitive-affective processes for motivation to change. In the discussion of their theory, the authors highlight leverage points for possible interventions. Finally, the authors show how their microlevel theory relates to other prominent, more macrolevel-oriented theories of clinician practice change.