Extension professionals enter their role with content-specific expertise; however, experience in volunteer leadership and management competencies is often limited. This study focused on the effectiveness of the Achieving the Extension Mission Through Volunteers (AEMTV) course in preparing professionals to use the Identification, Selection, Orientation, Training, Utilization, Recognition, Evaluation (ISOTURE) model to learn and apply volunteer systems concepts in a cohort-based online learning environment. We used quantitative and qualitative methods to assess how the course impacted participants and the programs they lead. Data from 127 participants indicated they increased their knowledge, improved volunteer systems, and influenced the quality of programming delivered in communities. Our research confirmed that the ISOTURE model (Boyce, 1971; Dolan, 1969) continues to be an effective framework for learning and applying volunteer systems management practices. We recommend that Extension collaborates across states to formalize and create additional online professional development relevant to all program areas to elevate Extension's impact nationally.