The assessment participation of students with disabilities is now an important part of students' education and educational decision-making. While much attention has been paid to the participation of students with significant intellectual disability, little research exists regarding the extent to which students with mild intellectual disability participate in the accountability system. This study represented a secondary analysis of the National Longitudinal Transition Study-2 (NLTS2). The study focused on to what extent secondary students with mild intellectual disability participated in mandated assessments (i.e., does not participate, alternate assessment, general assessment with accommodations, and general assessment without accommodations) as well as the relationship between participation and educational factors, such as special education curriculum, core classes in general education, and postschool goals. Participation in assessments by students with mild intellectual disability was multifaceted with the majority taking an alternate assessment. However, statistically significant relationships existed between assessment participation and special education curriculum, language arts and mathematics in general education, and postschool goals. Implications of the results are discussed in light of educational planning for students with mild intellectual disability.