Diagnosis, presentation to care, and initiation of antiretroviral therapy during the early stages of HIV have substantial individual and public health benefits. However, current estimates of the HIV care continuum, or care cascade, indicate that most HIV-infected persons in the US are diagnosed late in the course of their disease and even more do not achieve viral suppression. The purpose of this dissertation was to characterize the cascade-related behaviors of persons participating in active transmission networks and examine the geographic barriers to early diagnosis. Using data collected as part of the North Carolina (NC) Screening and Tracing of Active Transmission Program, we assessed the HIV status and if HIV-infected, the diagnosis, care, treatment and viral suppression status of named partners of persons acutely-infected with HIV (index AHI case) between 2002 and 2013. More than one-third of all traceable partners were HIV-infected. Most observed transmission events appeared attributable to previously-diagnosed partners (77.4%, 95% confidence interval 69.4-85.3%), of whom only 23.2% (14.0-32.3%) were in care and on treatment near the index AHI case diagnosis. Among phylogenetically-linked cases and partners, 60.6% of partners were previously diagnosed (43.9-77.3%). Using HIV surveillance data from a 52-county region in central NC, we mapped new diagnosis rates by stage of disease (early, chronic, and AIDS) and testing period (2005-2007, 2008-2010, 2011-2013). Maps were standardized and the percent overlap of high rate diagnoses (top 10th, 25th and 50th percentile) by disease stage and testing period were assessed. We identified a definite, underlying core area of HIV as represented by disproportionately high overlap in the top 25th and 50th percentiles by disease stage and testing period. The identification of early infection varied geographically over time, suggesting changes in testing behaviors or the epidemic itself. Relatively high rates of AIDS diagnoses persisted over time in the southeastern part of the study area. Finally, we assessed the association of distance to a publicly-funded testing site with stage of disease at diagnosis. Traveling longer distances to the testing site of diagnosis, particularly when a closer testing site was available, increased the prevalence of post-early stage diagnoses (prevalence ratio=1.09, 1.03-1.16).