High School Exiting Among Autistic Students: A National Analysis of Special Education Data from 2015 to 2019.

The Individuals with Disabilities Education Act (IDEA) provides special education services to students with disabilities, including autistic students, until age 21. However, the ages at which autistic students exit high school-and the reasons for exit-are not well documented, despite their importance for transition planning. We analyzed U.S. Department of Education Section 618 Part B data for special education students ages 14-21 across five school years (2014-2015 to 2018-2019) to examine exit age and exit category, with comparisons among autistic students, students with intellectual disabilities (IDs), and students with other disabilities. Using publicly reported counts of students exiting at each age, we derived mean exit ages by transforming age-specific count data. In 2019, 71% of autistic students graduated with a diploma, compared with 48% of students with IDs and 72.5% of students with other disabilities. Autistic students had lower dropout rates (6-8%) than students with other disabilities (15-18%). The mean exit age for autistic students was approximately 18 years, with an average graduation age of 17.9 years, indicating that many students exited prior to the end of extended IDEA eligibility in their state. These findings provide descriptive context on when autistic students exit high school relative to IDEA eligibility and underscore the importance of transition planning and coordination with adult service systems, though these factors were not directly examined in the present analysis.