Objective: An examination of the academic achievement of children with ADHD by stimulant treatment status must consider this heterogeneity of the disorder. With the dissemination of the final wave of data, the Special Education Elementary Longitudinal Study presents an opportunity to examine the academic achievement of students with ADHD using a large, community-based, and nationally representative sample over 4 years. Method: In Study 1, the association between stimulant treatment and academic achievement is examined over 4 years. In Study 2, the association between stimulant treatment and academic achievement is examined acknowledging the influence of subtype symptoms of ADHD using growth mixture modeling. Results: Results indicate significant differences in academic achievement according to long-term stimulant treatment status within each subtype symptom class. Conclusion: Research should acknowledge the influence of subtype symptoms when examining outcomes such as academic achievement. The upcoming "DSM-V" should consider the results as indicating the educational relevance of ADHD subtype classification. (Contains 3 tables and 4 figures.)