Five in-depth, semistructured interviews on what constitutes best practices were conducted with key professionals experienced in serving the homeless population. A practice model emerged from the interviews wherein client self-determination was considered a keystone. Self-determination theory was then used as a framework for understanding the best practices that emerged, and the relationship between client self-determination and positive outcomes. Implications are discussed for the older homeless, highlighting that although general best practices are applicable for this subgroup, the unique factors of an aging homeless population must be incorporated into best practice discussions.