The direct medical care costs have been relatively small to date compared to the costs of all illnesses, and even the estimate of $8.5 billion in costs in 1991 represents only a small percentage of total health care expenditures. However, the concentration of the disease in major metropolitan areas is already causing serious problems for local governments and public hospitals in these areas. These problems will become worse, with particular impacts on the large percentage of people who lack health care insurance or coverage. Two estimates have also been made of the indirect costs of AIDS in terms of lost productivity from illness and premature death. Both estimates used the human capital method, focusing on wages lost and the present value of future earnings. AIDS accounted for an estimated 2.1 percent of the total indirect costs of all illness in 1986, but by 1991 it is expected to represent 12 percent of the total indirect costs. The cost estimates do not include costs for persons with AIDS-related complex or those infected with HIV and who seek medical care. Adding in these costs as well as the costs of testing, research, and education might make the 1991 total more than twice as high as estimated. 10 references.