In the past decade, American professional psychology has taken significant steps toward a unified statement of the competencies that define the practice of psychology, regardless of specialty. The purpose of this article is to explain the current competency initiative in professional psychology and examine its implications and potential impact on graduate training in school psychology. A brief overview of competency-based training and the current competencies initiative in psychology is presented. Two significant challenges to implement competency-based training are then discussed. The first challenge has to do with conceptualizations of training and practice across accreditation agencies. As a part of the discussion, two recently published competency documents from the Assessment of Competencies Benchmark Workgroup of the American Psychological Association and the National Association of School Psychologists are compared in a content analysis. The second challenge discussed is the difficulties associated with operationalizing and measuring competencies. Specifically, the empirical and consequential bases for existing assessment methods are examined. In spite of current pressure by accrediting agencies to implement a competency-based training model, based on the challenges examined in this article, significant work remains if school psychology trainers want to assure that competency-based training is done well. (Contains 1 table.)