School counselors are professional educators who are responsible for the academic, social-emotional, and career development of students. The direct and indirect services that school counselors provide are vital for students but are more vital for students with disabilities. However, the roles and responsibilities of school counselors continue to evolve. Using a qualitative single case study approach and the social cognitive theory (SCT) as a theoretical framework, this study investigated the effects that middle school counselors in a Florida public school district had on student development outcomes of middle school students with disabilities. Although the SCT comprises six constructs, this study specifically focused on three constructs (i.e., reciprocal determinism, self-efficacy, and behavioral capability) that described the middle school counselors' job performance, wellness, and specialized training essential to the development of student outcomes. An in-depth description of the subject matter was provided by eight purposefully selected participants. Data collection included an electronic survey and a follow-up one-on-one interview. The findings from the study revealed that administrator support affected the self-efficacy of middle school counselors, direct and indirect services provided to students with disabilities was limited due to the increased duties assigned to middle school counselors, middle school counselors had to advocate to protect their role as a professional middle school counselor, and middle school counselors had to commit to providing career development to students with disabilities. The findings from the study have significant implications for SCT and for improving policy and decision-making processes in the field of school counseling. [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.]