As a result of increases in life expectancy, as well as the aging of the baby-boom generation, demand for family caregiving to the older population is likely to increase. [...] The growing demand for care provided in the home has focused the attention of federal and state governments on efforts to expand programs that provide services and supports to family caregivers. [...] For two-thirds of this group (65.5%), informal care is the only source of care provided in the home; another quarter (25.9%) receive some combination of informal and formal care, and the remainder (8.5%) receive formal care alone. [...] There is wide variation in these estimates for several reasons, including differences in the definitions of caregiver and care recipient, the amount and intensity of care provided, and the data collection methodology. [...] Estimates at the high end of the range include those individuals who provide care to the adult-disabled or to individuals of all ages and use a less restrictive measure of disability that may also include short-term disability or acute spells of illness.