Educating students with disabilities has been a challenge for schools across the United States and throughout the world for quite some time. At Frederick Law Olmsted #156, a gifted and talented school within the Buffalo Public Schools, academic performance on New York State Regents Exams reveals the challenge is most prevalent in the mathematics department, where three-year trends from the 2016-17 School Year to the 2018-19 School Year indicate students with disabilities are performing an average of 29 points below general education students. A mixed methods study was conducted answering the question: How do teachers view their beliefs about academic performance and opportunities for students with disabilities at Frederick Law Olmsted #156? After administering the Teacher's Sense of Efficacy Scale (Tschannen-Moran & Woolfolk Hoy, 2001), two separate focus groups with special education teachers and mathematics teachers were conducted. The findings reveal teachers, regardless of their specialty, report "quite a bit" of efficacy for student engagement, instructional strategies, and classroom management yet the way in which they describe the specifics of each and other factors in teaching, i.e., instructional strategies, student misbehaviors and reasons for misbehaviors, are very different. Special education teachers also express a belief that students with disabilities cannot perform at the same level as their peers. To address the differences in teacher perspective and beliefs, a differentiated professional development plan using an altered model of the current professional learning communities is proposed. [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.]