In this report the authors analyze the movement of students to and from the Milwaukee Parental Choice Program (MPCP) and Milwaukee Public Schools (MPS). They also analyze student mobility between schools within each sector. The analysis rests on two separate sets of data: the administrative records the authors have collected as part of their separate analysis of academic achievement in MPCP (Witte, Wolf, Cowen, Fleming, & Lucas-McLean, 2010), and the results of an extensive set of surveys collected from parents of private and public school students. The administrative records indicate that there is more within-sector school switching in MPS, but MPCP students are more likely to move to MPS than MPS students are to move into the private-school voucher program. Racial/ethnic and gender characteristics of the various types of movers do not appear markedly different. Moving students scored lower, on average, on the Wisconsin Knowledge and Concepts Exam (WKCE) in the year prior to their move, although the authors are not able in this report to say whether students moved because of their achievement levels or because of other factors. The survey records indicate that parents of students who move are less satisfied with their child's academic experiences and are more likely to give lower overall assessments of their child's school. MPCP students are more likely to have considered a public school option at some point prior to the survey than are MPS students likely to have considered a private school. Comparison of switcher designation (from student records) and parental survey indicating a new school is appended. (Contains 13 figures, 12 tables and 14 footnotes.) [Additional funding for this report was provided by the Robertson Foundation.]