This article provides a historical review of certified occupational therapy assistant (COTA) education, professional roles, career mobility, and professional development. The evolution of COTA education from 2 hospital-based, 12-week training programs to the current 162 accredited 2-year college degree or professional certificate programs is examined. The expansion of the COTA role from well-delineated direct service provider to advanced practitioner able to assume leadership roles within the profession is explored. Historic and current programs and methods supportive of COTA career mobility and professional development goals, including the Career Mobility Program, continuing education, career laddering, and the Advanced Practitioner program are described.