Geriatrics refers to medical care for older adults, an age group that is not easy to define precisely. Gerontology is the study of aging, including biologic, sociologic, and psychologic changes. “Older” is preferred over "elderly," but both terms are equally imprecise. It is important to avoid terms and attitudes that suggest bias against older adults (ageism). Although there is no set age to define older age, age 65 is often used because this is the age that determines eligibility for Medicare insurance in the United States. However, some people with medical conditions require geriatrics expertise at a younger age. Geriatricians are doctors with special training in evaluating and managing older adults’ healthcare needs and treatment.