Effective instruction for students with intellectual disability (ID) requires thoughtful planning and careful selection of instructional materials. One of the most popular websites for educators is Teachers Pay Teachers (TPT), an online marketplace that allows users to buy or sell a range of instructional materials for use in the classroom. The purpose of this exploratory study was to examine how special education teachers select and use instructional materials from TPT with students with ID. Additionally, I examined the relation between special education teachers' characteristics and self-efficacy ratings, and their use of and beliefs about TPT. This study utilized a cross-sectional survey design, and all participants completed a questionnaire about their selection and use of instructional materials from TPT. Study participants included 245 high school special education teachers of students with ID who downloaded at least one item from TPT during the 2020-2021 school year. Almost all participants considered the match between instructional materials and content taught when selecting items, and most made modifications after downloading. Cost also influenced teachers' selection of instructional materials with most reporting that they paid for items without reimbursement. Teachers of students with profound support needs were found to be significantly more likely to consult the TPT website than those who did not work with students with profound support needs. Additionally, teachers with the highest self-efficacy scores were significantly more likely to have positive beliefs about TPT than teachers with lower scores. Possible explanations for these findings and implications for future research and practice are addressed. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]