A growing body of research has documented the detrimental effects of changing schools on students' academic performance. One role of the federal Migrant Education Program is to implement strategies to redress migrant students' educational disruption. This report examines various approaches used to promote continuity of instructional service for migrant students. Case studies were carried out on four groups of two or three districts each that share migrant students over the school year ("trading partners"). The case studies revealed that the trading partners shared a set of common themes that led to the development of successful solutions for migrant students. These themes include a shared vision of the role of migrant education, emphasis on program alignment between trading partners, use of technology to transfer information between partners or provide distance education to students, and interpersonal relationships across districts. The case studies also displayed consistent conditions that led to educational discontinuity for migrant students: lack of timely and reliable information about student achievement levels and educational needs, interstate and interdistrict differences in curriculum requirements and instructional methods, and student conflicts between school and work. Secondary credit accrual poses the most critical challenge for interstate coordination; flexible courses of study for secondary students and strategically placed staff who "negotiate" coordination between students' educational experiences and graduation requirements are needed. Appendices present the case studies, which describe each trading partner, specific problems migrant students faced at each site, how these problems provoked innovations, each site's solutions, and coordination strategies implemented by the trading partners. (Contains 9 references and 6 exhibits.) (SV)