ABSTRACT: In 2015, an estimated 17.7 million U.S. persons were informal caregivers who provided substantial services through in-home, unpaid assistance to their family members and friends (1). Caregiving can have many benefits, such as enhancing the bond between caregiver and recipient, but it can also place an emotional and physical strain on caregivers, leading to higher rates of depression, lower quality of life, and poorer overall health (2). As the U.S. population continues to age (3), the need for informal caregivers will likely increase. However, little nationally representative information on prevalence of caregivers is available. This study examined demographic characteristics and health status of informal caregivers from 44 states,* the District of Columbia (DC), and Puerto Rico, based on data from the Behavioral Risk Factor Surveillance System (BRFSS) collected during 2015-2017. Overall, approximately one in five adults reported that they had provided care to a family member or friend in the preceding 30 days. Fifty-eight percent of caregivers were women, and a majority were non-Hispanic white, with at least some college education, and married or living with a partner. Across all states, 19.2% of caregivers reported being in fair or poor health, although significant state-to-state variation occurred. Caregivers provide important support to family members, friends, and the health care system and might compromise their own health to provide this support (1,2). Better understanding of caregivers and the challenges they face could inform implementation of improvements in support systems that could enhance not only the health of the caregiver, but that of the care recipient as well. For example, additional data regarding demographics at the state level might aid in more effective planning and support of caregivers with evidence-based programs and assistance (https://www.cdc.gov/aging/publications/features/caring-for-yourself.html).