Physicians who participate in abortion and medically assisted death in the United States work at the margins of institutionalized medicine. What motivates them to engage in such "dirty work"? This article uses ethnographic materials from two recent projects to analyze physicians' roles as gatekeepers to contested medical services. Abortion and medically assisted death share many similarities: They are both deeply stigmatized practices that are heavily restricted in many U.S. jurisdictions, and which many physicians are reluctant to participate in for moral, religious, or professional reasons. They both also confer medicine with the power to govern life and death decisions through the apparatus of state law. However, state laws operate quite differently on physicians in these two cases, with different outcomes. This comparative analysis demonstrates how dirty work in medicine enrolls the agency and subjectivity of physicians in distinctive ways that may be eclipsed by totalizing biopolitical frameworks. abortion, medical aid in dying, physicians, agency, biopolitics, United States.