U.S. Food and Drug Administration (FDA) policy prohibits blood donation from men who have had sex with men (MSM) even one time since 1977. Growing moral criticism claims that this policy is discriminatory, a claim rejected by the FDA. An overview of U.S. blood donation, recent donor deferral policy, and the conventional ethical debate introduce the need for a different approach to analyzing discrimination claims. I draw on an institutional understanding of injustice to discern and describe five features of the MSM policy and its FDA context that contribute to its discriminatory effect. I note significant similarities in the 1980s policy of deferring Haitians, suggesting an historical pattern of discrimination in FDA deferral policy. Finally, I point to changes needed to move toward a nondiscriminatory deferral policy.