Secondary teachers who are co-teaching in inclusion classrooms face a variety of demands and challenges that are exclusive to the high school setting (Keefe & Moore 2004, Smith, 1997, and Mastropieri & Scruggs 2001). Teachers' current teaching practices are built upon their past teaching experiences. The meanings teachers take away from their past experiences and their interactions with people and objects culminate in their expectations of what should happen with their teaching practices in the future. The results of this study reveal secondary teachers' understanding of inclusion in the areas of co-teaching partnerships, student engagement, and necessities required for co-teaching partnerships to be successful. By reflecting on their past experiences the teacher participants in this study explained the meanings they had developed from their experiences. A symbolic interactionism theoretical framework was used to examine the participants' different meanings of symbols that reflect their inclusion experiences.