The Developmental Stages of an Extension Professional (DSEP) model depicts how professionals can move through the stages of service, education, management, and leadership to build volunteer and program capacity. It encourages Extension professionals to assess the situation and adjust their leadership style. Researchers used a mixed methods approach to assess Dr. James Rutledge's DSEP model. Findings confirmed training Extension professionals in the DSEP model throughout the Achieving the Extension Mission through Volunteers course led to positive behavior change when working with volunteers. Extension needs to train professionals and utilize the DSEP model to build program capacity through volunteer engagement.