Collaboration with caregivers and between disciplines and agencies is a recommended practice in the field of early intervention and early childhood special education (EI/ECSE) as well as required by federal legislation for young children with disabilities. Review of relevant literature suggests that collaboration entails a complex set of principles and practices that are essential for teams and programs to employ if they are to ensure effective and sustained change. Despite the recognized complexity of collaboration in EI/ECSE, few systems frameworks have been proposed that organize the essential components of effective collaboration. We offer a framework that defines the core components of collaboration in EI/ ECSE. The proposed system further identifies and operationalizes the infrastructure and practices associated with the components and the levels of action at which these practices operate. (author abstract)