In this study we analyze information on self-reported health insurance coverage, HIV screening by insurers, and loss of health insurance. We distributed questionnaires to gay male participants in the Baltimore and Los Angeles sites of the Multicenter AIDS Cohort Study and to leukemia patients and gay AIDS patients seen at the Johns Hopkins Hospital. In this unusually well-educated and well-insured group, 90% of participants without AIDS had private health insurance coverage, compared with only 64% of participants with AIDS. Persons with AIDS (PWAs) were 33 times as likely to have Medicaid as persons without AIDS, and PWAs were 5 times as likely to have lost health coverage altogether as persons without AIDS.