The living arrangements of older persons play a key role in their use of formal and informal care, as well as in their health and well-being. Nurses engaged in primary care, discharge planning, and home care are strategically positioned to contribute to an optimal fit between older persons and their home environment. This article describes the demographic significance of late-life living arrangements and proposes a model for organizing the complex web of factors associated with household composition and late-life migration. The article then summarizes qualitative and quantitative evidence in support of the proposed model. Key areas for nursing research and strategies for applying available research are identified.