Despite the importance of timely entry into care after HIV diagnosis, the timing of care entry has not been described recently in a large, diverse population of persons with HIV. Dates of HIV diagnosis and entry into HIV care were obtained by interview of HIV-infected adults, most of whom had entered care for HIV, in 18 U.S. states from 2000 through 2004. Time to care entry was analyzed as a dichotomous variable; delayed care entry was defined as care entry greater than 3 months after HIV diagnosis. Multivariable logistic regression models were used to describe HIV testing-related factors associated with delayed care entry. Among 3942 respondents, 28% had delayed care entry. Diagnostic testing-related characteristics associated with delayed care entry included anonymous and first-time HIV testing. Providers of HIV testing should be aware that those who test positive anonymously and those whose first HIV test is positive may have increased risk for delayed HIV care entry. Developing programs that reinforce timely linkage to HIV care, targeted at those at increased risk for delaying care entry, should be a public health priority.