Undocumented migrants are people within a country without the necessary documents and permits. They are considered at higher risk for health problems because of their irregular status and the consequences of economic and social marginalization. A systematic review found 122 documents that suggested policies and interventions to improve health care access and delivery for undocumented migrants. Undocumented migrants mostly have only access to emergency care across Europe, and even in the countries where they are fully entitled to health care, formal and informal barriers hinder their access. This raises concerns for both public health and migrant care. On the basis of findings, policy options are suggested regarding data collection, research, entitlement to health care, information and communication, training and intersectoral approaches.