As pre-kindergarten (pre-k) expands across the country, school districts are making choices about where to place pre-k classrooms and developing policies for how families can apply and who is enrolled. In doing so, districts are pulling policy levers that influence students' access to pre-k. Research shows that some families have less access to pre-k than others, which contributes to inequitable enrollment within districts. This study explores whether and how Chicago's school-based pre-k system was more equitable after the district implemented a set of policies focused on changing access to and "enrollment" in school-based pre-k. The outcomes from Chicago's efforts offer key insights for other school districts implementing similar efforts nationwide. [For the research report, see ED612485.]