Medical-legal partnerships integrate legal advocates into health care settings to address health-related social needs. However, their effect on health outcomes is unclear. This retrospective cohort study examined the effect of referral to a medical-legal partnership on hospitalization rates among urban, low-income children in Greater Cincinnati, Ohio, between 2012 and 2017. We compared 2,203 children referred to a pediatric primary care-based medical-legal partnership with 100 randomly selected control cohorts drawn from 34,235 children seen concurrently but not referred. We found that the median predicted hospitalization rate for children in the year after referral was 37.9 percent lower if children received the legal intervention than if they did not. We suspect that this decrease in hospitalizations was driven by the ability of legal advocates to address acute legal needs (for example, threat of eviction and public benefit denial) and, when possible, to confront root causes of ill health (for example, unhealthy housing conditions). Interventions such as those provided through a medical-legal partnership may be important components of integrated, value-based service delivery models.