The Building Assets, Reducing Risks program—an intervention designed to ease students’ transition to high school—is working to find out how professional development changes for new and more experienced schools implementing the program. BARR is the first intervention funded under the federal Education Innovation and Research program (and its predecessor, the Investing in Innovation program) to build up enough evidence over time to move from initial development to full scale-up. Its current study could help policymakers understand how to sustain school improvement programs in the long term.