People who have mental health diagnoses are often subject to sanist microaggressions in which pejorative terms to describe mental illness are used to represent that which is discreditable. Such microaggressions reflect and perpetrate stigma against severe mental illness, often held unconsciously as implicit bias. In this article, I examine the sanist attitudes that underlie sanist microaggressions, analyzing some of the cognitive biases that support mental illness stigma. Then I consider what responsibility we have with respect to microaggressions. I argue that all people share in a collective responsibility to engage in acts of epistemic resistance that challenge sanist attitudes so that it is easier for bystanders who witness microaggressions, and targets of microaggressions in particular, to identify microaggressions and to point out biased behavior. The act of pointing out bias is best understood as an act of epistemic resistance that is more effective and meaningful in the context of other acts of epistemic resistance. Ultimately, whether to point out bias is an individual decision that one must make after weighing the risks involved; engaging in a range of acts of epistemic resistance, on the other hand, is a moral responsibility everyone shares.