Adopted persons face special challenges in the development of identity, as aspects of their histories may be unknown, making it difficult to construct a coherent narrative linking past, present, and future. Extensive literature on adjustment outcomes for adopted persons indicates an elevated risk for adjustment problems. In this study, a low-risk sample of adopted youth is involved to examine, longitudinally, connections between adoptive identity and adjustment. Participants included 145 adopted youth who participated in Waves 2 (W2: adolescence: mean age = 15.7) and 3 (W3: emerging adulthood: mean age = 25.0) of a longitudinal study with a nationwide sample. Children were placed with same-race adoptive families (over 95% White) as infants through domestic private adoption agencies in the U.S. Internalizing and externalizing behaviors were assessed by the Youth Self Report (W2) and the Adult Self Report (W3). Adoptive identity was assessed by ratings of 6 dimensions coded from interviews which, using cluster analysis, revealed 4 adoptive identity subgroups: unexamined, limited, unsettled, and integrated. Factorial ANCOVA examined mean differences in W3 internalizing problems across identity clusters while controlling for W2 internalizing. The main effect for adoptive identity cluster was significant: F(3, 840.72) = 3.724, p = 0.011. Adopted adolescents in the unsettled group had significantly higher levels of internalizing problems in emerging adulthood than persons in the unexamined and limited categories. A similar ANCOVA for W3 externalizing behavior was not significant. Identity profiles high in negative affect may be at particular risk of increased levels of internalizing problems.