This study examined resource utilization, cost of care, and balance of care relationships for people with dementia on the boundary of community and residential care in Ireland.A balance of care approach was used to examine how investment in personalized community care impacted on measured formal and informal costs, care relationships, and potential admission to long-stay care facilities for people with dementia over a three year period.181 people with dementia on the boundary of community and residential care received additional personalized care supports to help them remain living at home in the community. The estimated average weekly cost of community care for these people, including usual formal care provision, new personalized supports, consumption, and housing, was €418 per week, less than half the cost of potential residential care. However, when informal care is valued using an opportunity cost methodology, the social cost of community-based care increased threefold, rising above the cost of alternative residential care.Investment in personalized supports can support family carers to continue caring for longer, thus postponing expensive admission into long-stay care facilities. However, family-care costs remain high, irrespective of the additional supports received.