Student mobility is a common phenomenon that disproportionately affects students in high-poverty schools. Research shows that students who move repeatedly are likely to fall behind in reading and other academic areas. This article reviews proactive strategies that high-poverty districts and schools are using to reduce the harmful effects of student mobility. Such schools should implement an enrollment plan that places incoming students at their appropriate level, a schoolwide instructional plan that gives them the ongoing support they need, and a coordinated assessment plan that closely monitors their progress. Districtwide consistency and good communication with parents are also important factors in easing transitions to new schools. (Contains 1 table.)