Although magnet schools were created in the 1960s to integrate schools, their policy, legal, and demographic context has changed dramatically, making it more difficult for them to integrate. As it becomes more difficult for magnet schools to integrate, other benefits, such as improved student achievement, become more important. At the same time, it is unclear how well magnet schools can improve student achievement when their ability to integrate is hindered. To examine magnet schools in a modern context, this study utilized data from one of the nation's largest districts. The data include information for more than 400,000 students and over 100 magnet schools across seven school years (2007/2008 through 2013/2014). The study examined student achievement by looking for improvements in math and reading scores on a standardized exam. Multiple strategies were used to address selection bias. The large sample of magnet schools enabled an examination of aspects of magnet school policies that have not been examined before. Much of the analysis is broken down by magnet type to better understand how different magnet policies influence the results. The results provide little evidence of student achievement benefits from magnet schools. Most estimates point to a null or negative effect. School-within-a-school programs seem to be the most beneficial magnet type, with evidence of achievement gains in both reading and math. There could, however, be other benefits to students from magnet schools, as the range of outcomes studied here was limited.