A new working paper from the National Bureau of Economic Research tests whether low income families live in neighborhoods that offer few opportunities for income mobility because they prefer these places (e.g., to be near family), or because they experience barriers to relocating. By providing services that reduce barriers—financial assistance, but also rental search assistance and landlord brokering—the authors find that the share of families who move to higher opportunity areas increases from 14% in the control group to 54% in the treatment group. Families who make these moves do not express having made sacrifices to do so, and express high satisfaction with their new neighborhoods. The authors conclude that these structural barriers are a driver of residential income segregation, and suggest that more customized housing supports are an especially important component of affordable housing programs.