Using insights drawn from mediation practice, social justice scholarship, and debates on ethical thinking in other professional fields, the authors argue that prevailing ethical codes for mediators in the United States stunt the development of ethical thinking in the field. Current codes and even their critiques take a “top-down” approach that proceeds from the perspective of the mediator and gives primacy to abstract principles rather than to the particulars and contexts of disputes. This approach ignores a much richer practice on the ground, depends on an artificial division of procedural and substantive justice, and constricts the scope of ethical questions raised, inhibiting effective systemic solutions. The authors argue for ethics grounded in the context of particular substantive areas, which do not focus on the mediator alone and which remain open to a wider set of social justice considerations.