["Journal of Intellectual Disability Research, EarlyView. ", "\nABSTRACT\n\nBackground\nPeople with intellectual and developmental disabilities (IDD) experience significant health and healthcare disparities. Home and community‐based services (HCBS) are crucial for the health and well‐being of adults with IDD, and national regulations mandate person‐centred planning (PCP) for all HCBS service administration. Despite these requirements, limited evidence exists on how PCP impacts health outcomes. This study examines the association of PCP and health outcomes, unmet healthcare needs and preventative care access.\n\n\nMethods\nThis study uses 2021–2023 National Core Indicators for Intellectual and Developmental Disabilities (NCI‐IDD) In‐Person Survey data from 36 states, with an analytical sample of 12 022 adults with IDD. Three composite measures were constructed to capture distinct self‐reported dimensions on the person‐centredness of the planning meeting, service plan and service coordination. Each measure was dichotomised to distinguish dimensions that were not fully person‐centred (0) from those that were (1). Dependent variables include seven items on health outcomes, unmet healthcare needs and preventative care. Modified Poisson multivariate regression models examined the association of PCP and health and healthcare outcomes via adjusted relative risk estimates.\n\n\nResults\nPeople with fully person‐centred planning meetings and service coordination were less likely to have unmet needs in finding doctors (0.79, p = 0.018; 0.74, p = 0.037) and managing medications (0.72, p = 0.004; 0.74, p = 0.031). Fully person‐centred service coordination was associated with lower unmet mental health needs (0.75, p = 0.025), better self‐reported health (0.84, p = 0.019) and lower chance of emergency room visits (0.89, p = 0.019). Service coordination consistently showed the largest protective influence against unmet needs and adverse health outcomes.\n\n\nConclusions\nThis study contributes new evidence that PCP, and particularly person‐centred service coordination, is associated with better health and healthcare outcomes for people with IDD. These findings are crucial for addressing IDD health disparities and offer insights for state compliance with national quality measurement requirements for PCP.\n\n"]