Improving school systems is critical to bridging the achievement gap and achieving federal accountability goals. Research in three urban districts partnered with a university-based intermediary organization sheds light on promising instructional reform strategies and challenges to bringing about systemwide change. Analyses of district efforts to promote the instructional leadership of principals, support teacher learning through school-based coaches, specify curriculum, and promote data-based decisionmaking identify common factors constraining and enabling instructional improvement. The research also shows that third-party organizations can help facilitate policy alignment and build the capacity of district staff to lead instructional change. [This research brief describes work documented in "The Role of Districts in Fostering Instructional Improvement: Lessons from Three Urban Districts Partnered with the Institute for Learning," by Julie A. Marsh, Kerri A. Kerr, Gina Ikemoto, Hilary Darilek, Marika Suttorp, Ron W. Zimmer, and Heather Barney.]