Under what circumstances should a citizen be able to avoid the penalties set by the citizen's home country's criminal law by going abroad to engage in the same activity where it is not criminally prohibited? Should we view the ability to engage in prohibited activities by traveling outside of the nation state as a way of accommodating cultural or political differences within our polity? These are general questions regarding the power and theory of extraterritorial application of domestic criminal law. In this Article, I examine the issues through a close exploration of one setting that urgently presents them: medical tourism. Medical tourism is a term used to describe the travel of patients who are citizens and residents of one country, the "home country," to another country, the "destination country," for medical treatment. This Article is the first to comprehensively examine a subcategory of medical tourism that I call "circumvention tourism," which involves patients who travel abroad for services that are legal in the patient's destination country but illegal in the patient's home country--that is, travel to circumvent domestic prohibitions on accessing certain medical services. The four examples of this phenomenon that I dwell on are circumvention medical tourism for female genital cutting (FGC), abortion, reproductive technology usage, and assisted suicide. I will briefly discuss the "can" question: assuming that a domestic prohibition on access to one of these services is lawful, as a matter of international law, is the home country forbidden, permitted, or mandated to extend its existing criminal prohibition extraterritorially to home country citizens who travel abroad to circumvent the home country's prohibition? Most of the Article, though, is devoted to the "ought" question: assuming that the domestic prohibition is viewed as normatively well-grounded, under what circumstances should the home country extend its existing criminal prohibition extraterritorially to its citizens who travel abroad to circumvent the prohibition? I show that, contrary to much of current practice, in most instances, home countries should seek to extend extraterritorially their criminal prohibitions on FGC, abortion, assisted suicide, and, to a lesser extent, reproductive technology use to their citizens who travel abroad to circumvent the prohibition. I also discuss the ways in which my analysis of these prohibitions can serve as scaffolding for a more general theory of circumvention tourism.