What happens when teachers are given funding and time to identify and develop targeted and innovative professional learning? This article focuses on lessons learned from grants funded through the California Department of Education that were designed to do just this. As the state and the nation consider the best approaches to professional learning for educators, it is important to understand how this model worked and how it might inform state and national policy and practice. Common Core implementation is requiring the development of new models of professional growth in order to provide teachers with the support and relevant experience necessary to build their skills and expertise. The grants were part of California's Teacher-Based Reform (T-BAR) program. The program's intent was to support teacher-driven professional development by allowing teachers to select professional learning that would meet their personal learning needs and be responsive to their local school context. Individual projects varied widely in subject area, targeted grade levels, and project details. The specific anticipated outcomes of each project also varied, although actionable professional learning enabling better support for student learning was a consistent theme. The findings reported in this article are based primarily on a survey, administered in fall 2014, to all 287 participating teachers in one of the state T-BAR regions. The authors also conducted a case study examination of three teacher teams to augment survey findings. Questions probed the extent to which teachers' T-BAR project influenced their own professional growth, collaboration, and engagement, and how what they learned and did impacted their students, schools, and districts.