This study measures costs associated with first-time homeless families and individuals incurred by homeless and mainstream service delivery systems in six study communities. Unaccompanied individuals were studied in Des Moines, Iowa; Houston, Texas; and Jacksonville, Florida. Families were studied in Houston, Texas; Kalamazoo, Michigan; Upstate South Carolina; and Washington, DC. Past research has primarily documented costs associated with homelessness for individuals with chronic patterns of homelessness or severe mental illness. Newer work has been published on the costs incurred within the homeless system for families experiencing first-time homelessness. This study provides additional findings that help to improve our understanding of homelessness and its associated costs. It presents ideas about opportunities for cost savings, and it advances an approach for measuring costs that, coupled with other evaluation methods, can help communities understand the cost-effectiveness of different homelessness interventions.