Housing programs are complex social interventions. Research on housing for people with mental illness has proceeded without a framework for integrating emerging findings and guiding new research directions. This paper describes a definition and model of housing stability developed with stakeholders in 3 local housing systems for people with mental illness. The model describes housing stability as a dynamic relationship among 3 factors (person, housing, and support) that are influenced by broader system influences. The model is discussed in terms of its usefulness for integrating existing research, guiding new research, and integrating research with practice to improve housing practices.Over the past two decades there has been some progress in research on housing programs for people with serious mental illness. Despite the methodological limitations of much of this research, including the absence of more rigorous experimental designs (Newman, 2001), there is emerging evidence that a variety of attributes of housing are associated with better outcomes for consumers of mental health services. These attributes include housing that is well-maintained, that supports individual choice and control, that is managed in an empowering and democratic fashion, and that provides consumer-centred, rehabilitation-oriented support ( Newman, 2001;Parkinson, Nelson, & Horgan, 1999).