Adopted youth often do not achieve in school as well as their non-adopted peers. We used data from the High School Longitudinal Study to examine high school and postsecondary achievement outcomes in adopted youth. We compared outcomes for domestically adopted youth, internationally adopted youth, and non-adopted youth. Results indicate that domestically adopted youth have lower grade point averages. Internationally adopted youth were less likely to enroll in fouryear postsecondary institutions than were non-adopted youth.Research on the academic achievement of adopted children suggests that whereas adopted youth do not differ from their peers and siblings on measures of intelligence, they do not achieve equally as well in school (van IJzendoorn et al., 2005). Indeed, adopted youth often experience academic and psychological struggles at greater rates than their non-adopted peers (Duszynski et al., 2015). These challenges place them at risk for not succeeding in school.This achievement gap has been attributed to a variety of potential causes, including delays in cognitive development (e.g., Grotevant & McDermott, 2014), as well as to the emergence of psychological problems (e.g., Logan et al., 1998) and behavioral problems (e.g., Juffer et al., 2004;. Although research on the academic achievement of adopted youth has been plentiful, few studies have actually examined long-term achievement outcomes for these students. In the present study, we add to this literature by examining academic outcomes assessed both at the end of high school and in postsecondary settings, for students who had been adopted either domestically or internationally.