Engagement in HIV care needs to be improved. Important factors to be considered in attempts to improve engagement in care include the following: (1) initial linkage and subsequent retention are distinct processes; (2) engagement in care is vital for HIV treatment success at both the individual and population levels; (3) missed clinic visits can identify patients at high risk for poor health outcomes; (4) engagement in care is worse in groups bearing a disproportionate burden of the domestic HIV epidemic; and (5) ancillary services play a crucial role in improving linkage to and retention in care.