What level IQ is considered mental retardation for an adult?

Mental retardation is a term that is no longer used in the medical field. The current diagnostic term is intellectual disability, and it is defined by a score below 70 on a standardized IQ test, accompanied by significant limitations in adaptive functioning in areas such as communication, self-care, and social skills. Scores of 70-85 are below the average range, and are characterized by mild difficulties with learning and adaptive behavior.