This article begins with a consult of a patient using the International Classification of Functioning, Disability, and Health (ICF), published by the World Health Organization in 2001. The ICF framework serves as the conceptual model for the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Sixth Edition. In contrast to the issues of morbidity-centric documentation schemas, the ICF platform provides a standardized nomenclature to chart functioning, specifically an integrative biopsychosocial model of functioning that defines the components of functioning. The ICF qualifier serves as the titratable dimension of function; the qualifier not only satisfies the need for charting progress but also, when aggregated, provides the possibility of identifying the quantitative metrics of a cohort (eg, service needs, length of hospitalization, level of care, functional outcomes, and return-to-work potential). Implementing ICF into routine documentation moves practitioners toward the concept of functioning not as a consequence of disease but rather toward the real-life dynamics among health condition, body function, body structure, and environmental factors that determine functioning. ICF will be an essential basis for the standardization of data concerning all aspects of human functioning and disability around the world. ICF will be useful for persons with all forms of disabilities, not only for identifying health care and rehabilitative needs but also in identifying and measuring the effect of the physical and social environments.