This longitudinal study examines the influence of homelessness on maternal health and health behaviors. Using data from the Fragile Families and Child Wellbeing Study, it follows 2,631 families from 20 large US cities over 5 years. Over that period, 9.8 percent of the sample reportedly experienced at least one homeless spell and an additional 23.6 percent experienced one or more doubled-up episodes. Estimated rates of disability, depression, and anxiety are two to three times higher for the homeless group than for those with no homeless spell. Mothers who become homeless are found to have poorer health outcomes both before and after homelessness. The study’s findings suggest that homelessness has a modest but distinct effect on maternal health outcomes. They also suggest that mothers who have young, low-income families and health problems, particularly behavioral health problems, can be promising targets for interventions designed to prevent or divert individuals from homelessness.