This paper describes the structure of the shelter system in the City of Philadelphia and the patterns by which homeless people utilize that system. The shelter system is found to be segregated by age, gender, family and disability status, with the young single men and families concentrated in the largest facilities (capacity more than 100). A majority of the city's shelters are run on a for-profit basis, man of which are small "board and care" facilities, although the plurality of shelter beds are in large, not-for-profit shelters. Data are reported which reveal an annual rate of turnover in the shelter system of approximately 6 persons per bed, with an annual "average length of stay" of 60 days per client. However, repeat users are likely to account for as much as one third of the shelter population at any given time. Considered together, these findings suggest that, for many people, the shelter serve primarily as a short-term supplement to a restricted range of housing opportunities in the community. The research and policy implications of this pattern of utilization are discussed.