It is widely agreed that foreign sponsors of research in low- and middle-income countries (LMICs) are morally required to ensure that their research benefits the broader host community. There is no agreement, however, about how much benefit or what type of benefit research sponsors must provide, nor is there agreement about what group of people is entitled to benefit. To settle these questions, it is necessary to examine why research sponsors have an obligation to benefit the broader host community, not only their subjects. Justifying this claim is not straightforward. There are three justifications for an obligation to benefit host communities that each apply to some research, but not to all. Each requires a different amount of benefit, and each requires benefit to be directed toward a different group. If research involves significant net risk to LMIC subjects, research must provide adequate benefit to people in LMICs to avoid an unjustified appeal to subjects’ altruism. If research places significant burdens on public resources, research must provide fair compensation to the community whose public resources are burdened. If research is for profit, research sponsors must contribute adequately to the upkeep of public goods from which they benefit in order to avoid the wrong of free-riding, even if their use of these public goods is not burdensome.