The characteristics of clients reporting no health insurance were compared with those reporting any health insurance at publicly funded human immunodeficiency virus (HIV) counseling and testing sites in the United States during 1992. Thirty of 65 funded health departments collect data on self-reported health insurance status. Data were dichotomized into two groups, clients reporting any health insurance versus those reporting none, and multivariate logistic models were developed to explore independent associations. Of the 885,046 clients studied, 440,416 reported that they lacked health insurance. Clients without health insurance were more likely to be male, members of racial or ethnic minorities, adolescent, and HIV seropositive. Prisoners (odds ratio = 0.26), clients of Hispanic ethnicity (odds ratio = 0.52), and clients receiving testing during field visits (odds ratio = 0.53) in drug treatment centers (odds ratio = 0.55) and in tuberculosis clinics (odds ratio = 0.55) were less likely to have health insurance. Injecting drug users, whether heterosexual (odds ratio = 0.65) or homosexual (odds ratio = 0.67), were less likely to have health insurance compared with other behavioral risk groups. Large numbers of clients receiving publicly funded HIV counseling and testing lack health insurance. Lack of health insurance may interfere with subsequent receipt of needed primary care services among high-risk clients, especially HIV seropositive clients in need of early intervention services.