Rosalyn Carter is often quoted for her observation that “there are only four types of people in the world: (1) those who have been caregivers, (2) those who currently are caregivers, (3) those who will be caregivers, and (4) those who will need caregivers.” There are three distinct groups of informal caregivers, roughly defined by the age of the people they care for: (1) children with chronic illness and disability are typically cared for by young adult parents, (2) adult children with such conditions as mental illness are cared for by middle-aged parents, and (3) older individuals are cared for by their spouses or their middle-aged children. Because the nature of caregiving differs substantially for children and adults, we describe each of these groups separately. We begin with adults, who are by far the largest group of people receiving health-related caregiving.

There are no exact estimates of the number of informal caregivers in the United States. Prevalence estimates vary widely depending on the definitions used and the populations sampled. At one extreme are estimates that 28.5 percent of the U.S. adult population, or 65.7 million people, provided unpaid care to an adult relative in 2009, with the majority (83 percent) of this care being delivered to people age 50 or older (National Alliance for Caregiving and American Association of Retired Persons, 2009). This number, based on the Behavioral Risk Factor Surveillance System survey (Centers for Disease Control and Prevention, 2006), approximates the estimated 59 million adults with a disability in the United States. At the other extreme, data from the National Long-Term Care Survey suggest that as few as 3.5 million informal caregivers provided instrumental activities of daily living (IADLs) or activities of daily living (ADLs) assistance to people ages 65 and over (not to all adult care recipients). Intermediate estimates of 28.8 million caregivers (“persons aged 15 or over providing personal assistance for everyday needs of someone age 15 and older”) are reported by the Survey of Income and Program Participation (National Family Caregivers Association and Family Caregiver Alliance, 2006). A recent national survey of individuals ages 45 and older yielded a caregiving rate of 12 percent or 14.9 million adults in that age group (Roth et al., 2009).

These differences are in part attributable to the period of data collection, the age range of the population sampled, the populations targeted, and, most importantly, the definition of caregiving. Thus, the high-end estimates are generated when broad and inclusive definitions of caregiving