Background: Urgent Medical Aid (UMA) is the procedure entitling undocumented migrants (UM) to access healthcare in Belgium. It regards medical aid which urgency is evaluated and attested by a registered medical doctor. This research assessed the c hallenges in granting UMA from the perspectives of UM and healthcare professionals in order to improve the accessibility and availability of UMA for UM. Methods: In 2015, 33 in - depth interviews with UM and 6 focus groups with healthcare professionals and m anagers were conducted in 5 major Belgian cities. Data were analyzed applying De Bie’s & Roose’s framework of 7 dimensions of access to and quality of healthcare. Results: As defined by law, UMA can encompass both preventive and curative healthcare as well as drug prescription. Yet, the word “urgent” is too frequently interpreted as “emergency” care impacting both the UM’s health seeking behaviour as the decision making of the healthcare provider refusing to provide care. Further, also the social welfare or ganisation regularly refuses to enact their role of reimbursing costs because they don’t consider it as urgent (n)or medical care. Secondly, all stakeholders indicated that the paucity of information on what UMA entails, the lack of standardized implementa tion protocols and the limited transparent communication on how decisions are made leads to problems for all parties involved. Conclusions: The ambiguity of the term “urgent medical aid” and the lack of clear information and communication on UMA procedures directly hampers the access to health care for UM in Belgium, and leaves room for discretionary practices by all parties involved. Changing its name into “Necessary Health Aid”, and issuing standard protocols and sensitization material could help to clari fy what is meant by the procedure, as long as more structural ways of granting access to health care cannot be assured. Message: • The ambiguity of the term “urgent medical aid” directly hampers UM’s access to health care. • The lack of protocols leaves ...