This Advisory is based on Technical Assistance Publication (TAP) 21, Addiction Counseling Competencies: The Knowledge, Skills, and Attitudes of Professional Practice. It discusses the development of the counseling competencies and the validated research on which they are based, provides a simplified overview of their structure and the elements of a typical competency, and outlines how these competencies are changing the field of substance use disorder (SUD) treatment nationwide. The Advisory also addresses the critical role of cultural competency.