To allocate limited economic and other resources for HIV prevention and treatment for maximum benefit, health policy planners and decision makers require accurate, current estimates of the lifetime costs of HIV-related illness and the impact of therapy on the quality of life of HIV-infected persons. These data are central input parameters to the economic evaluation methodology known as cost-utility analysis. The estimates available in the literature are already outdated, and this paper presents updated estimates of the projected lifetime health care costs associated with HIV disease in the United States and the number of quality-adjusted life years (QALYs) lost to HIV in light of recent advancements in HIV diagnostics and therapeutics. Results indicate that the lifetime cost of HIV medical care has grown from about $55,000 U.S. to more than $155,000 U.S., while the number of QALYs lost per case of HIV infection has decreased from 9.26 to 7.10, when discounted at a 5% annual rate. When these figures are discounted instead at the newly recommended 3% rate, lifetime costs rise to more than $195,000 U.S. and lost QALYs increase to 11.23. The net effect of these increases in the medical costs of care and treatment saved by averting an HIV infection and in QALYs makes HIV prevention a relatively more cost-effective strategy than other, non-HIV health-related programs.