Individuals with intellectual and developmental disabilities (IDD) in the U.S. predominantly live with their family caregivers. As care delivery and support systems vary widely globally, consideration of caregiver outcomes specifically in the U.S. context is needed. A systematic literature review was conducted to identify U.S. family caregiver outcomes and their association with existing services and supports for family caregivers of adults with IDD. Twenty-four articles were compiled using the PubMed, Web of Knowledge, PsychInfo, and CINAHL databases. Studies report economic, mental, and physical health outcomes from caregiving roles. The need for comprehensive caregiver assessment is discussed. Understanding and responding to the changing needs of family caregivers is vital to the U.S. disability service system to effectively prioritize formal resources and services.