The study considers annual health care utilization and costs associated with human immunodeficiency virus (HIV) infection and the autoimmune disease syndrome (AIDS) complex by applying the previously developed disease and disease combination-specific cost of illness methodology. This study documents changes in age-specific mortality rates indicating the decline in age groups "20-39". We estimate annual economic losses resulting from twenty-four HIV/AIDS-related diseases among the U.S. population to be $18.2 billion. This estimate includes direct medical cost of almost $9.2 billion, 80% of which is compensated by Medicaid. We demonstrate that an add-on therapy with additional mean cost of $7,100 per person per year would be justifiable if it could reduce the risk of progression to AIDS by 19%.