New York City's school system is among the most diverse and segregated in the United States. Using difference-in-differences and placebo tests, we evaluate two desegregation policies in two geographic districts in New York City, District 3 and District 15. Both districts attempted to lower economic segregation within their district while maintaining school choice, prioritizing economically disadvantaged students for middle school seats in advance of the 2019-2020 school year. District 15, however, set more ambitious prioritization targets and also chose to eliminate academic screens from all middle schools. We find that District 15's policy lowered economic segregation in sixth grade by 55% and racial segregation by 38%, while District 3's policy led to no significant change in segregation.