International medical travel (IMT) challenges the notion of health care as a responsibility of a nation-state to its citizens, tied to the territory of a nation-state. As patients travel for medical care, they invoke not territorialised notions of citizenship, but make new claims. In this article, the authors propose the term 'flexible bio-citizenship' that extends the notion of 'flexible citizenship' to describe transnational mobilities for the accumulation of biovalue. They argue that people who travel for medical care come from a variety of backgrounds, identities and circumstances for whom the physical and economic ability to travel and cross borders is a form of flexible social capital enabling them to access levels of care otherwise inaccessible to them. The article explores the implications upon citizenship for a diverse range of people who travel for their health care: from highly mobile cosmopolitan professional expatriate workers, regional border crossers, migrant workers, those who cannot afford care at home, patients whose status makes treatments unavailable, and outsourced patients forced to travel for care. Their mobility allows them to gain biovalue but also alters their citizenship relationships and perspectives.