Across the US, some schools are hallmarks of high academic performance. These schools display consistently high test performance, and their students are sought after by competitive colleges and universities. These schools are successful, with consistently above-average test scores, low dropout rates, high percentages of children attending college, and active and involved parents. By most measures, these schools are considered great. But high-performing schools face unique challenges for continuous improvement. The role of professional developers is to provide experiences that cause teachers, principals, and other educators to reflect on their practices and to continually work toward changing those practices to improve all students' achievement. In this article, the authors discuss six challenges for high-performing schools that aim to achieve more, the lessons they have gleaned from their work with the Minority Student Achievement Network.