The lives of people with intellectual disabilities are tightly intermeshed with the philosophies and practices of special educators, therapists, psychologists, social workers, and others who make up the mental retardation field. These nonmedical workers represent a kind of extended family, which can strongly influence the decisions made and services received by the people they serve. By contrast, most individuals with mental retardation do not have extraordinary medical needs, and healthcare professionals play only a minor role in their human services family. There are deeply rooted historical differences between the medical model of mental retardation with which genetics professionals are familiar and the philosophies embraced by nonmedical workers who dominate the mental retardation field. These contrasts have an important impact on the genetic diagnostic process, as well as a more global effect on mental retardation research. Without the full participation of teachers, therapists, psychologists, and others outside the medical setting, many practical applications of genetic research can neither be implemented nor expanded upon, and an important opportunity for cross-fertilization is lost. It is in the interest of the genetics community to take advantage of recent overtures by the mental retardation field to forge new alliances and broaden its perspectives on intellectual disability.