Postsecondary enrollment rates in the United States have grown tremendously; however, completion rates have not significantly changed over the last 20 years. Studies have found that International Baccalaureate Diploma Programme (IBDP) participants have higher postsecondary completion rates than their counterparts. The purpose of this qualitative collective case study was to explore how the IBDP's curriculum and instructional practices fostered noncognitive college readiness and self-efficacy in Central Florida high school students. The theoretical framework for this study was Bandura's theory of self-efficacy, which emphasizes that an individual's confidence in their abilities is constructed through experiences that provides feedback on their capacity to complete the task successfully. The theoretical constructs of mastery experiences, vicarious experiences, and verbal persuasion were used to explore how the IBDP curriculum and instructional practices fostered noncognitive college-readiness skills. This qualitative collective case study used Yin's (2018) explanation building process to explore the lived experiences of 10 students at DeLand High School's IBDP world school. The data collected suggests that the IBDP's curriculum and instructional practices actively promote mastery experiences that develop noncognitive college readiness skills. Limited evidence was found that the IBDP curriculum actively promotes vicarious and verbal persuasion experiences that develop noncognitive college-readiness skills. This study suggests that IBDP students develop noncognitive college readiness skills prior to entering postsecondary institutions, which allows them to be successful postsecondary learners. Future research needs to be done in other IBDP world schools to further confirm the inclusion of noncognitive college readiness skills in the IBDP's curriculum and instructional practices. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]