The COVID-19 pandemic, an external stressor with multiple stressful sequelae, has fundamentally changed people’s lives over multiple years. In this article, we first review research demonstrating that the pandemic has negatively impacted people’s sense of belonging and health over time. Next, we draw upon decades of theoretical and empirical work demonstrating that threats to belonging and mental health problems are highly interrelated, with increases in the former driving increases in the latter. We then extend this discussion to physical health, drawing upon a wealth of theoretical and empirical work demonstrating that threats to belonging are a risk factor for longer term health problems and premature mortality. We also highlight potential mechanisms linking threats to belonging and health, with a focus on sleep and immune function. Throughout, we review how pre-existing vulnerabilities may moderate these processes. We conclude with empirically supported recommendations for policymakers interested in addressing these issues.