This commentary considers policy implications of research in this volume and elsewhere, and we emphasize the benefits of policy approaches that move “upstream,” to the prevention of homelessness. Policies that address the structural causes of homelessness, described by numerous articles in this ANNALS volume, are the furthest upstream and may be the most important in eradicating homelessness, and policies aimed at prevention are next. We point out that effective prevention requires targeting those most at risk, and we call for creative use of data and better coordination with institutions and systems that may be able to identify the antecedents to homelessness. We note that currently, the homelessness shelter system is strained, so we argue for a radical rethinking of its role, with a shift of resources to efforts further upstream. The existing racial disparities in both pathways to and incidence of homelessness bring urgency to making more than marginal policy changes.