Abstract: Under what circumstances should a citizen be able to avoid the penalties set by his or her home country’s criminal law by going abroad to engage in the same activity in a place 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 – the travel of patients who are citizens and residents of one country, the 'home country,' to another country, the 'destination country,' for medical treatment – is a growing multi-billion dollar industry involving thousands of patients each year from the United States alone. This Article is the first to comprehensively examine a sub-category of medical tourism I call 'circumvention tourism,' involving 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 abortion, Female Genital Cutting (FGC), assisted suicide, and reproductive technology usage. I briefly discuss the 'can' question: Assuming a domestic prohibition on access to one of these services is lawful, as a matter of international law is the home country permitted, forbidden, or mandated to extend its existing criminal prohibition extraterritorially to home country citizens who travel abroad to circumvent the home country prohibition? Most of the Article, though, is devoted to the 'ought' question: Assuming the domestic prohibition is viewed by the home country as normatively well-grounded and lawful, 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 the current practice, in most instances home countries should seek to extend extraterritorially to circumvention tourists their criminal prohibitions on abortion, FGC, assisted suicide, and to a lesser extent reproductive technology usage. I also discuss the ways in which this analysis can serve as scaffolding for a more general theory of circumvention tourism. This Article is the third in a trilogy of law review articles I have done on various aspects of Medical Tourism. The first Article, Protecting Patients with Passports: Medical Tourism and the Patient Protective-Argument, 95 Iowa L. Rev. 1467 (2010) is available at: http://ssrn.com/abstract=1523701. The second Article, Medical Tourism, Access to Health Care, and Global Justice, 52 Virg. J. Int'l L. 1 (2011), is available at: http://ssrn.com/abstract=1926880.