Millions of individuals and families in the United States do not have access to stable housing. Recent policies in the United States and the rest of the developed world emphasize programs intended to prevent homelessness through temporary financial assistance. This article explores the impact of the largest homelessness prevention program in U.S. history, the Homelessness Prevention and Rapid Re-housing Program (HPRP), on residential instability, using a national sample of families with children enrolled in school. The identification strategy exploits variations on the location of HPRP providers. Using data on the ratio of K–12 students experiencing homelessness in school districts, we find that HPRP is associated with reductions in the percentage of homeless students for districts closer to an HPRP provider. However, the impacts of HPRP fade out when program benefits end, bringing into question whether homeless prevention can help families achieve self-sufficiency in the long run.