A substantial number of people living with human immunodeficiency virus (HIV) have never received HIV medical care despite the benefits of early entry to care. The United States has no population-based system that can be used to estimate the number of people who have never received HIV care or to monitor the reasons that care is delayed. Although local efforts to describe unmet need and barriers to care have been informative, nationally representative data are needed to increase the number of people who enter care soon after diagnosis. Legal requirements to report all CD4 counts and all HIV viral load levels (indicators of HIV care) in most states now make national estimates of both care entry and non-entry feasible. The Centers for Disease Control and Prevention (CDC) and five state and local health department jurisdictions are testing and evaluating methods for a standardized supplemental HIV surveillance system to characterize HIV-infected people across the U.S. who have not entered HIV care after their diagnosis. This article reviews the context, rationale, and potential contributions of a nationally representative surveillance system to monitor delays in receiving HIV care, and provides data from the formative phase of the CDC pilot project.