An increased level of parent involvement in education has been identified as a predictor of positive postschool outcomes for students with disabilities who have traditionally experienced lower rates of employment and postsecondary education than their peers without disabilities. The purpose of this study was to explore the factor structure of scales adapted from the Hoover-Dempsey and Sandler Model of Parent Involvement that might be used to predict parent involvement in secondary special education. An iterative adaption process included adding and revising scale items to reflect parent beliefs and involvement activities related to transition planning and secondary education for parents of high school students with disabilities. Participants were 149 parents of students with disabilities, ages 16–21. Two exploratory factor analyses (EFA) were conducted to examine the psychometric properties of the scales. Results of the EFA for involvement activities suggested a three-factor solution including: Future Planning; Home-based Involvement; and Agency/School-based Involvement. Results of the EFA for Motivators for Involvement suggested a seven-factor solution including: Parent Expectations for the Future; General School Invitations; Role Construction; Perceptions of Time and Energy; Knowledge, Skills, and Self-efficacy; Specific Child Invitations, and Specific Teacher Invitations. Implications and future research directions are discussed.