What happens when people with HIV apply to immigrate to Canada? Screening Out takes readers through the process of seeking permanent residency, illustrating how mandatory HIV testing and the medical inadmissibility regime are organized in such a way as to make such applications impossible. This ethnographic inquiry into the medico-legal and administrative practices governing the Canadian immigration system shows how this system works from the perspective of the very people toward whom this exclusionary health policy is directed. As Laura Bisaillon demonstrates, mandatory immigration HIV screening triggers institutional practices that are highly problematic not only for would-be immigrants, but also for those bureaucrats, doctors, and lawyers who work within that system. She provides a vital corrective to state claims about the functioning of – and the professional and administrative practices supporting – mandatory HIV testing and medical examination, pinpointing how and where things need to change.