The findings from this qualified phenomenological research study involved 20 secondary general education teachers who taught inclusion classes. The research study investigated the lived experiences and perceptions of teachers through in-depth interviews and using a modified van Kaam method of data analysis, Atlas.ti 6 software, and Microsoft Excel to corroborate involvement between teacher efficacy and dissonance. Ten themes emerged from the research study: (a) class size, (b) students’ learning modalities, (c) dissonance from high-stakes testing, (d) inadequate professional development, (e) inclusion classes required an inordinate amount of preparation, (f) teachers should receive higher compensation for instructing inclusion classes, (g) empathy for special-needs students, (h) dissonance had an adverse effect on efficacy, (i) pressure from high-stakes testing increased teacher dissonance, and (j) co-teachers should have subject matter content certification. All the emerged themes influenced the quality of teacher efficacy. Recommendations include provision for enhanced meaningful professional development for teaching in the inclusion setting that will produce optimal results for students.