This article examines the issue of internal legitimization and its importance in securing high-quality community engagement in K-12 schools. Drawing on the literature from the fields of community engagement, school reform, school-university partnerships, and school-community partnerships, this article describes some of the prevailing challenges and barriers external partners face when conducting reform oriented partnership work in K-12 schools. The discussion focuses on four factors that contribute to enhancing external partners' internal legitimization within K-12 settings. The article offers a set of strategies for working through each of the four components.