Epistemic trust—trust in the relevance and utility of social learning—is central to helping processes between clients and workers in helping services. Yet, due to their experiences, clients may adaptively develop predispositions toward stances of epistemic mistrust or epistemic credulity. From an AMBIT (adaptive mentalization-based integrative treatment) perspective, this article argues that epistemic mistrust and credulity are both caused by social injustice and generate further social injustice. Helping services commonly respond in ways that fail to acknowledge this social injustice and, perversely, deliver further injustice still. Our primary focus is how these issues relate to work with clients, but we argue that they are present in work within AMBIT's other foci, too: in teams, multiagency networks, and learning. We conclude that workers and helping services have a moral duty to recognize and attend to the multiple social injustices associated with epistemic mistrust and credulity.