Drawing on the work of Badiali and Titus (2010) and Bacharach, Heck, and Dahlberg (2010), we define coteaching as the following: both cooperating teacher and teacher candidate are engaged in student learning at all times through daily coplanning, coinstructing, and coassessing. We argue that collaborative planning (e.g., sharing ideas, developing instructional materials for feedback, sharing resources), instructing (i.e., the development of specific roles using a coinstructional strategy), and assessing (collaborative evaluation, grading, and reflection on both formative and summative assessments) are the keys to successful coteaching.