Collaborative teaching, or co-teaching, is a powerful way to support the learning of students with diverse learning needs. But how do you know when you're doing it right? And if you're not, what can you do about that? Authors Wendy W. Murawski and Wendy W. Lochner introduce the Collaborative Teaching Improvement Model of Excellence (CTIME), a continuous improvement model that embraces personalized professional learning to ensure that teachers meet the core competencies for co-teaching without burning out along the way. Incorporating a systematic application of collaborative groups, data analysis, microteaching, feedback, and collegial support, CTIME is the culmination of the best research in the field.