Project Summary Congregate settings, such as large urban jails, have been significantly impacted by COVID. While prevention strategies from hospitals can be implemented, there are unique challenges to preventing transmission within jails that warrant additional attention. Our primary objective of this supplement is to model infection prevention and mitigations strategies for COVID in a large urban jail. Specifically, we will test strategies that have been employed at the jail at (1) admission to the jail, (2) during incarceration, and (3) at discharge to gauge the impact each strategy has had and to forecast downstream impact of COIVID in jails. We will also examine the impact of COVID spread in jails on the burden of infection in the community. One major strategy employed across the country to reduce spread within jails is to encourage release of low-risk, nonviolent offenders. However, the downstream impact in the community of this intervention is unknown and it is critical to examine what intermediate steps may be necessary, i.e. a ‘step-down’ quarantine period. Given the central role the jail is hypothesized to play in propagating the spread of MRSA to high-poverty, inner-city neighborhoods, our proposal to examine COVID has significant