Abstract: Objective To review the nomenclature and terminology, diagnostic criteria, classification and evaluation of intellectual disability using WHO ICD-11 and ICF.
Methods The theories and approaches of ICD-11 and ICF were adopted to analyze the nomenclature and terminology, diagnostic criteria, classification and evaluation of intellectual disability.
Results ICD-11 and ICF had established the nomenclature and terminology, diagnostic criteria, classification and evaluation of intellectual disability from the perspectives of content model of ICD-11 and functioning of ICF respectively. Intellectual disability had used nomenclature of disorder of intellectual development and one of sub-categories of mental, behavioral or neurodevelopmental disorders. Intellectual disability was also defined as both impairment of intellectual function (b117) and functional limitation of adaptive behaviors (d1-d9) using ICF. Occurrence age of intellectual disability was before 18 years old for diagnostic criteria of ICD-11 and ICF.
Conclusion The nomenclature and terminology, diagnostic criteria and classifications of intellectual disability have been reviewed and updated using the theories and approaches of ICD-11 and ICF. It provides theoretical supports, approaches, and standardized tools for the development of rehabilitation service for people with intellectual disability.

Key words: intellectual disability, terminology, diagnosis, classification