This article examines the cost-effectiveness of providing permanent supported housing to homeless people with mental illness. Through the use of billing records and frequency of use charts, researchers were able to map the service usage of a cohort of 268 homeless individuals from both urban and rural communities. The results suggest that significant cost savings can be achieved by establishing supportive housing programs from the homeless rather than forcing them to rely on emergency services. Data from this study can inform policy changes at both the State and Federal level. It can also provide for the introduction of common themes of money and cost-effectiveness which all of the stakeholders in the service funding debate can use. Further recommendations and uses for the data are described and discussed. (Contains 2 figures and 3 tables.)