The data presented were acquired from each State's central child abuse register for either a representative sample of migrant children or all eligible subjects through a record linking process. The subject's names, obtained from the State's annual migrant education census, were individually cross referenced with the register data bases to determine if they had been involved in a reported incident of maltreatment. The information acquired was converted to incidence estimates that were contrasted with the rates for all children in the respective States and were decomposed to identify high risk cohorts within the migrant population. Patterns of specific types of physical abuse, sexual abuse, and neglect also were established. One finding common to all five assessments was that migrant children were significantly more likely to be maltreated than other children, although these incidence rates varied appreciably from one State to another. Rates of abuse and neglect for migrants ranged from a maximum of 46.4 children per thousand in Florida to a minimum of 5.1 children in Pennsylvania. This paper emphasizes the unique methodology employed in research, issues pertaining to provisions for accessing central registers and protecting confidentiality of subjects, the generalizability of the findings, and cross-State incidence differentials for both migrants and children from nonmigrant families. Tables, figures and 13 references. (Author abstract modified)