The principal question of this study is the following: does peer-level ethnic-racial socialization have the same effect as from parents on Black adolescents ERI development? By effect, we mean whether ethnic-racial socialization can mitigate the adverse effects of discrimination and boost identity development? Linear growth modeling was used to estimate the changes of ethnic-racial identity across time. To detect how various sources of ethnic-racial socialization may mitigate discrimination and boost the ethnic-racial identity development of Black adolescents, our study incorporated moderation analyses between socialization and discrimination. The results indicated that discrimination is associated with increased ethnic-racial identity development and that some forms of ethnic-racial socialization mitigate the effects of discrimination. Both peers and parents were able to mitigate discrimination through preparation for bias and boost ethnic-racial identity development. Thus, both peers and parents adequately socialize Black adolescents and prepare them for instances of discrimination.