In 2011, 18 million informal caregivers provided 1.3 billion hours of care monthly to about 9 million older adults receiving informal assistance with daily activities, according to estimates from the new National Survey of Caregiving. Family members continue to be the main source of informal care, and hours of care are concentrated among caregivers for higher need recipients. Informal caregivers provide an average 75 hours per month; hours are significantly more for spouses, other co-resident caregivers, and those assisting high-need recipients. Most caregivers reported substantial positive aspects of caregiving. Those who provide high levels of care, assist recipients with dementia, or have health problems themselves are most likely to report substantial negative aspects of caregiving. Beyond supportive care, most informal caregivers assist with a range of medically-oriented tasks or help recipients navigate the health system, making them an essential part of the workforce for maintaining health and well-being in the older population, as recognized by both the Administration for Community Living (ACL) and the National Plan to Address Alzheimer's Disease.