This study compares the demographic, clinical, and health care characteristics of 2,156 persons over and under age 65 who are participants in the Sonya Slifka Longitudinal Multiple Sclerosis Study and examines the effects of current age, age at diagnosis, course, and duration of illness on disability-related outcomes. Compared to younger MS patients, significantly higher percentages of older patients lived alone, had lower incomes, and were severely disabled; 85% needed help with activities of daily living and 40% received home care services. Almost all older patients had health insurance, 75% had prescription drug coverage, and few reported difficulty accessing general medical and specialized MS care; perceptions of health status and quality of life were relatively positive. Duration and course of illness were the major predictors of disability, although older current age and younger age at diagnosis were also associated. The relationship among age- and disease-related variables is complex and they likely exert independent effects on disability-related outcomes. Planning is needed by caregivers and policy makers to ensure that the specialized needs of elderly persons with MS are adequately met.