This article is the first of eight articles in this special issue on Family-Centered Early Intervention (FCEI) for children who are deaf or hard of hearing (DHH), or FCEI-DHH. In 2013, a diverse panel of experts published an international consensus statement on evidence-based Principles guiding FCEI-DHH. Those original Principles have been revised through a coproduction process involving multidisciplinary collaborators and an international consensus panel, utilizing the best available evidence and current understanding of how to optimally support children who are DHH and their families. This revision (referred to as expanded Principles) was motivated by the need to incorporate (a) input from family leaders and DHH leaders, (b) broader international and cultural perspectives, (c) new empirical evidence, and (d) research in human development. This Introduction provides an overview of the rationale, purposes, and main content areas to be addressed throughout the special issue.