Background: Persons with an intellectual and developmental disability frequently face barriers in accessing preventive services in community-based health care systems. As they age into middle years, they are at increased risk for functional decline. This paper presents a description of an advanced practice nurse (APN) intervention used in a pilot study that explored the feasibility of using an in-home preventive model based on a comprehensive geriatric assessment with persons ageing with an intellectual and developmental disability. Method: The APN intervention was fully provided to a sub-sample (n = 70) of 201 participants with an intellectual and developmental disability enrolled in a programme called "Stay Well and Healthy!" The APN intervention included an initial home visit for a comprehensive geriatric assessment with follow-up home visits to review health status and assess adherence with recommendations and provide education and support to promote health and prevent functional decline. Results: Advanced practice nurses identified a number of active health-related problems for persons ageing with an intellectual and developmental disability (mean 5.2; range 1-14) that had potential effects on function and survival. The majority of recommendations (mean 14.4; range 6-35) were for clinical preventive services (42.2%) and self-care for health-related issues (36.8%). Conclusions: This study showed that there were problems consistent with persons ageing with an intellectual and developmental disability and older adults without disability. The in-home preventive APN intervention to promote healthy ageing and reduce health disparities in this population is feasible, needed, and warrants further study.