This paper analyzes households' response to the introduction of intra-district school choice and examines the impact of this choice on student test scores in Pinellas County Schools. Households react strongly to the incentives created by such programs, leading to significant changes in the frequency of exercising alternative public schooling options, and changes in the composition of the "opt out" students. However, using proximity to public alternatives as an instrument for opting out of the assigned public school, the author finds no significant benefit of opting out on student achievement and that those who opt out of their default public schools often perform significantly worse on standardized tests than similar students who stay behind. Results further suggest that the short-run detrimental effects of opting out are stronger for students who opt out closer to the terminal grade of the school level. Yet the detrimental effects are weaker for disadvantaged students, who typically constitute the proposed target of school choice reforms.