Unstable housing, which includes poor housing quality, unstable neighborhoods, overcrowding, and other factors, is a significant social determinant of health for adults and children. This new study identified three forms of housing instability (being behind on rent, moving multiple times, and experiencing homelessness) associated with inadequate access to care and poor health outcomes; sought to determine their associations with caregiver and child health in household; and examined whether there was overlap between the three housing circumstances. The study used data from Children’s HealthWatch household-level surveys and medical record audits from 2009 to 2015 in primary care clinics and pediatric emergency departments, and the sample included 22,324 low-income renter households with children ages 4 and younger.