Immigration detention is the fastest-growing form of incarceration in the U.S. Numerous reports by advocacy groups and detainees themselves have alleged substandard medical care for detainees. We have undertaken an analysis of the health plan that regulates reimbursement of much of detainee health care. We conclude that this plan may place detainees at risk of receiving inadequate care, particularly if they have chronic medical problems or would benefit from routine health screening exams. We present several concrete measures that could immediately improve the level of medical care afforded to this vulnerable population.