A recent flurry of philosophical research on microaggression suggests that there are various practical and moral reasons why microaggression may be objectionable, including that it can be offensive, cause epistemic harms, express demeaning messages about certain members of our society, and help to reproduce an oppressive social order. Yet little attention has been given to the question of whether microaggression is also epistemically objectionable. This paper aims to further our understanding of microaggression by appealing to recent work on moral encroachment—the (...) idea that knowledge is sensitive to the moral stakes of believing—to argue that microaggression can be irrational in a distinctively epistemic sense, as it can involve relying on an epistemically unwarranted belief. This view suggests that the notion of epistemic justification may come apart from the notion of epistemic blame. (shrink)