In Singapore and worldwide, large numbers of people live with disabling illness. In the first part of this paper, we address the assessment of activities of daily living (ADL). Disability charting is important as a clinical tool to document functional recovery as well as to assess the effectiveness of medical and rehabilitation interventions. Disability assessment is also important epidemiologically, in developing social policies, planning disability resources and in medical research and education. We review the concepts and general principles of disability assessment with reference to the WHO International Classification of Functioning, Disability and Health (ICF) as well as to local contexts. We also describe in further detail 6 basic ADLs of feeding, dressing, toileting, transfers and mobility used in disability-related national schemes. In the second part of this article, we introduce how the concepts of frailty have changed the paradigm in which we approach geriatric rehabilitation, through interactive overlaps with the psychosocial, disability and comorbidity domains. We describe the consequences of functional deterioration in the frail elderly, and how to screen for frailty. We also outline therapeutic exercise as a form of prehabilitation to improve the resilience of these vulnerable people and possibly return them to robust health. Family physicians are best equipped in the management of frailty, as they have the holistic and comprehesive medical skill set to treat the associated comorbidity, disability and psychosocial domains in integrative geriatric rehabilitation.