The Functional Ability Rating Scale (FARS) is an instrument developed by local direct service workers in the field of human services to provide an objective measure of an individual's degree of limitation in seven areas of major life activity (MLA). The subject's level of functioning is assessed in Self-Care, Language and Communication, Learning Mobility, Self Direction, Capacity for Independent Living and Economic Self Sufficiency. FARS is intended to assess mentally retarded/developmentally disabled, mentally ill, and physically disabled individuals eighteen years of age or older. The scale consists of twenty-eight descriptions of component skills spread over seven areas of MLA. The rater is asked to score an individual according to his or her ability to perform the component skill, on a scale of one to five. Information can be gathered by several methods, in order of preference: (1) client interview/observation; (2) interview of client's significant others; and/or (3) review of client's case records. Reliability, validity, interrater Mobility, Self Direction, reliability, and test/retest reliability studies have been conducted using the Vineland Social Maturity Scale and the AAMD Adaptive Behavior Scale. The results are presented in table format. The scale and instructions for completing it are appended. (LMO)