Co-teaching has emerged as a strategy for ensuring that SWDs are taught to the general education curriculum while receiving specially designed instruction within the least restrictive environment (LRE) appropriate to their needs. One of the most important components of co-teaching is the relationship between the two teachers (Kohler-Evans, 2006), which has been described as a professional marriage (Friend, 2010). However, there is limited information on the factors influencing their relationship. This study seeks to add to the body of knowledge in co-teaching by studying if teaching experience has an effect on co-teachers' perception of their teamwork. Participants will include special and general educators who are currently paired with a co-teacher and come from eight, urban, diverse, public school districts in the northeastern part of the U.S. Co-teachers from grades K-12 will be invited to complete the Tuckman Team Maturity Questionnaire (TTMQ). This study will conduct a series of multivariate regressions using four independent variables (relationship age, primary role, school culture, and openness), three covariates (years of teaching experience, years of co-teaching experience, and grade band), and four dependent variables, the Tuckman stages of small group development (forming, storming, norming, performing). Further research of the co-teaching relationship is required as results may inform school administrators and district support staff in cultivating high performing co-teaching partnerships. [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.]