Before widespread antiretroviral therapy (ART), an estimated 17% of people delayed HIV care. We report national estimates of the prevalence and factors associated with delayed care entry in the contemporary ART era. We used Medical Monitoring Project data collected from June 2009 through May 2011 for 1425 persons diagnosed with HIV from May 2004 to April 2009 who initiated care within 12 months. We defined delayed care as entry >three months from diagnosis. Adjusted prevalence ratios (aPRs) were calculated to identify risk factors associated with delayed care. In this nationally representative sample of HIV-infected adults receiving medical care, 7.0% (95% confidence interval [CI]: 5.3-8.8) delayed care after diagnosis. Black race was associated with a lower likelihood of delay than white race (aPR 0.38). Men who have sex with women versus women who have sex with men (aPR 1.86) and persons required to take an HIV test versus recommended by a provider (aPR 2.52) were more likely to delay. Among those who delayed 48% reported a personal factor as the primary reason. Among persons initially diagnosed with HIV (non-AIDS), those who delayed care were twice as likely (aPR 2.08) to develop AIDS as of May 2011. Compared to the pre-ART era, there was a nearly 60% reduction in delayed care entry. Although relatively few HIV patients delayed care entry, certain groups may have an increased risk. Focus on linkage to care among persons who are required to take an HIV test may further reduce delayed care entry.