This article, part of a special issue on Family-Centered Early Intervention (FCEI) for children who are deaf or hard of hearing (DHH), outlines the foundational principles of FCEI-DHH. The principles are organized into three sections: Foundation Principles, Support Principles, and Structure Principles. This article focuses on the Foundation Principles, which emphasize the importance of ensuring that families with DHH children have access to early intervention (EI) and other appropriate supports, and the need for family-centered EI. The article highlights the critical aspects of providing early intervention following identification, including the importance of early, timely, and equitable access to supports. It also discusses the need for continuous audiological assessments and the provision of supports in various settings, such as home-based, center-based, and telepractice. Additionally, the article addresses the concept of equity, which involves removing barriers and ensuring that all families have equal opportunities to access quality services. The article provides recommendations for EI providers and families to ensure effective collaboration and support. Finally, it emphasizes the importance of family-EI provider relationships, including partnerships, engagement, capacity-building, and reflection, to foster the self-efficacy and capacity of families to nurture their children.This article, part of a special issue on Family-Centered Early Intervention (FCEI) for children who are deaf or hard of hearing (DHH), outlines the foundational principles of FCEI-DHH. The principles are organized into three sections: Foundation Principles, Support Principles, and Structure Principles. This article focuses on the Foundation Principles, which emphasize the importance of ensuring that families with DHH children have access to early intervention (EI) and other appropriate supports, and the need for family-centered EI. The article highlights the critical aspects of providing early intervention following identification, including the importance of early, timely, and equitable access to supports. It also discusses the need for continuous audiological assessments and the provision of supports in various settings, such as home-based, center-based, and telepractice. Additionally, the article addresses the concept of equity, which involves removing barriers and ensuring that all families have equal opportunities to access quality services. The article provides recommendations for EI providers and families to ensure effective collaboration and support. Finally, it emphasizes the importance of family-EI provider relationships, including partnerships, engagement, capacity-building, and reflection, to foster the self-efficacy and capacity of families to nurture their children.