In Cultures Built to Last, Rick DuFour and Michael Fullan (2013) argue that widespread, systemic change is possible not only within schools but across districts through a focus on building culture. A group of educational leaders in Rhode Island believe that collaborative learning through an extended professional learning community can lead to the systemic changes necessary to improve learning and teaching. In fall 2013, eight school districts in Rhode Island formed the East Bay Professional Learning Community (www.ebecplc.org) to launch a joint effort to develop a culture of assessment literacy through ongoing professional learning focused on team-specific action plans tightly aligned to school, district, and state initiatives. To accomplish this, the districts pooled their funding to engage a national expert to coach and guide their