Building district capacity for implementing Positive Behavioral Interventions and Supports (PBIS) in high need school districts is challenging. To better understand the level of support needed to successfully implement districtwide PBIS under challenging conditions, the National PBIS Center is conducting several model demonstrations of district-wide PBIS implementation in high need Local Education Agencies (LEAs). This practice brief summarizes the lessons learned one year into an intensive 5-year partnership with Southbridge Public Schools, a district identified as high need. The intent of the brief is to provide district leaders, trainers, and state leaders with lessons learned and suggestions they may consider when supporting high need LEAs. Four broad lessons were learned during the partnership and explored in this brief: (1) Invest in Relationships; (2) Invest in Leadership Capacity Building; (3) Invest in Data and Communication Systems; and (4) Continuously Reevaluate.