The SUPPORT trial highlights ethical challenges raised by comparative effectiveness randomized controlled trials (ceRCTs) involving one or more usual care interventions. Debate about the SUPPORT trial has focused on whether study interventions posed "reasonably foreseeable risks" to enrolled infants and, thereby, reflects a preoccupation with U.S. regulations. As ceRCTs are conducted globally, our analysis of the SUPPORT trial is grounded in internationally accepted ethical principles. We argue that the central ethical issue raised by the SUPPORT trial is the following: should the SUPPORT trial interventions be conceptualized as practice, or research? The answer to this question has important implications for "downstream" ethical requirements-including whether the usual care interventions in ceRCTs require research ethics committee review, undergo harm-benefit analysis, and are included in informed consent documents-and it is antecedent to the development of ethical guidance for ceRCTs.