The purpose of this article is to document an innovative and effective quasi-experimental, mixed methods approach developed for evaluating the effectiveness of magnet schools throughout the United States. Magnet schools continue to be one of the most common school choice mechanisms in the United States, and as a research team the authors have been evaluating the effectiveness of magnet schools in improving student achievement since 2010. In this paper, the authors share the evaluation research design that they have used through this work, with the intent of sharing best practices in effective magnet school evaluation with other scholars and practitioners engaged in work in similar school settings. Specifically, the authors here explain the benefits of various elements of their evaluation design: their selection of comparison schools, of comparison students within those schools, and their means of measuring magnet program implementation to evaluate the degree to which implementation affected student outcomes.