Prisons and substandard housing pose serious risks to individuals and communities during the COVID-19 pandemic. Limits on physical distancing are associated with disease outbreaks in shelters, camps, and prisons. The high prevalence of pre-existing illness in the settings places people at risk for medical complications. This project will generate evidence of ways to reduce the spread and impact of COVID-19 by analysing hospitalizations among people who were in custody or inadequate housing during the first wave of COVID-19 in BC. The project will also develop recommendations on the use of mandatory testing. The project team is drawn from established networks of researchers, decision-makers, service providers, and people who have experienced homelessness and time in custody.