Objectives: The present research examined if Blacks differ in how they categorize Blacks, Whites, and Black–White Biracials (Biracials, hereafter) as ingroup members and whether those categorizations predict the degree to which they attribute rejection feedback to discrimination. Methods: In Study 1 (N = 115), Black participants received rejection feedback from a Black, White, or Biracial online partner and then indicated the extent to which they perceived their partner as part of their racial ingroup and the extent to which they attributed the rejection feedback to discrimination. In Study 2a (N = 92), Black participants viewed the profile of a Biracial who self-identified as Black, White, or Biracial and then indicated the extent to which they perceived them as an ingroup member. Study 2b (N = 183) followed a similar design as Study 1 except that Black participants received rejection feedback from a Biracial online partner who self-identified as Black, White, or Biracial. Results: In Study 1, participants considered Black and Biracial partners to be more of an ingroup member than White partners and, in turn, were less likely to attribute rejection feedback to discrimination. In Study 2, participants perceived Biracials who self-identified as White, versus Black or Biracial, to be less of an ingroup member (Study 2a, 2b) and, in turn, were more likely to attribute rejection feedback to discrimination (Study 2b). Conclusions: Findings suggest that Blacks’ perception of a Biracial’s ingroup membership affects their attributions to discrimination following social rejection.