Transition services, particularly those that feature work-based learning experiences, often require designated staff to spend the majority of their time in the field. They also require that staff have the skills and supports to properly and effectively deliver these services. Training and monitoring these staff is critically important to ensure youth with disabilities experience strong employment outcomes. Maryland PROMISE was a statewide experimental, multicomponent, and community-based transition project that served 997 youth receiving Supplemental Security Income and their families. To ensure that staff effectively delivered services, Maryland PROMISE provided carefully designed professional development activities that included training, field-based coaching, and performance monitoring. This article reports on the Maryland PROMISE capacity building activities for project staff, provides data on the results of that process, and offers implications for the effective delivery of community-based transition services.