Federal law establishes minimum standards for protecting human research participants, but many states have enacted laws that may apply to research. Precision medicine research in particular implicates state laws that govern an array of topics, including human subjects research, genetic testing, and both general and genetic privacy and discrimination. Thus, the determination of which state’s laws apply, and under what circumstances, can substantially alter participant rights and protections. To shed light on this topic, we conducted interviews with experts in law, human research protections, and precision medicine research. Our goal was to better understand their experiences with choice of law issues, the effects of state law variation on research practices and stakeholder groups, and approaches to addressing such variation. Interviewees were aware of state-based variation in laws that could be applied to research. However, the extent to which they perceived such variability as problematic differed, as did their perceptions of stakeholder roles and responsibilities for addressing state law variation, and their estimations of requisite knowledge among IRBs and researchers. These divergent perspectives create an ethical and legal quandary, and further empirical and normative work is needed to fully characterize the implications of substantive differences in participant rights and protections.