In 1987, the National Public Health and Hospital Institute conducted a national survey of 623 acute-care hospitals to obtain information relating to inpatient and outpatient care for persons with acquired immunodeficiency syndrome (AIDS). Two hundred seventy-six hospitals reported treating persons with AIDS; the average length of stay was 16.8 days. Average costs and revenues per inpatient day were $681 and $545, respectively, with a cost per patient per year of $17 910. Estimated cost for AIDS inpatient care during 1987 was $486 million; Medicaid represented the primary payer. Regional and ownership comparisons for this year and between 1985 and 1987 indicated significant differences in utilization, payer source, and financing. Results suggest major differences in reimbursement and losses related to payer source or lack of insurance, with many hospitals that serve large numbers of low-income persons with AIDS encountering moderate to severe financial shortfalls. We conclude that increasing concentrations of persons with AIDS in relatively few hospitals in large cities may make it more difficult to secure the broader political base necessary to obtain adequate support for treatment. (JAMA. 1989;262:784-794)