BACKGROUND: Health service coverage cascades measure the proportion of a population in need of a service that experienced a positive health outcome from the service, and enable tracking of progress in achieving universal health coverage and inequities in care coverage. OBJECTIVES: To investigate HIV care coverage among HIV-positive adolescent girls and young women (AGYW) living in six South African districts, compare coverage by age and socioeconomic status (SES), and investigate other associated factors including participation in a combination HIV prevention intervention. METHODS: The HERStory Study was an evaluation of the combination intervention, comprising a representative household survey of AGYW aged 15 - 24 years living in six intervention districts. From September 2017 to November 2018, biological, sociodemographic and behavioural data were collected. HIV-positive status, initiation of antiretroviral therapy (ART) and viral suppression were determined through laboratory tests (enzyme-linked immunosorbent assay for HIV antibodies, antiretroviral (ARV) metabolites and viral load (VL) testing). Viral suppression was defined as a VL <1 000 copies/mL. Knowledge of HIV-positive status was self-reported, and participants testing positive for ARV metabolites were assumed to have known their HIV-positive status. Unconditional HIV care cascades were created, stratified by age and SES. We used Pearson's χ2 tests corrected for survey-based analysis to describe factors associated with knowledge of HIV status, and being on ART. RESULTS: Of the 4 399 participants, 568 were HIV-positive (12.4%), of whom 60.8% (95% confidence interval (CI) 57.1 - 64.5) knew their status, 50.6% (95% CI 46.6 - 54.0) were on ART, and 62.1% (95% CI 58.4 - 65.9) were virally suppressed. Most participants (84.9%) were in the lower SES group, and they had better coverage than the higher SES group: 61.9% (95% CI 58.3 - 65.4) knew their status, 52.1% (95% CI 48.4 - 55.9) were on ART, and 64.9% (95% CI 61.3 - 68.4) were virally suppressed, compared with 55.0% (95% CI 42.1 - 68.0), 40.0% (95% CI 29.2 - 50.8), and 46.6% (95% CI 34.5 - 58.7), respectively. Participants aged 15 - 19 years had slightly inferior coverage to the 20 - 24-year-old group: 57.5% knew their status, 46.1% were on ART and 59.5% were virally suppressed, compared with 62.3%, 52.2% and 63.3%. CONCLUSIONS: These findings emphasise the need to close the gaps in HIV care coverage among AGYW, of whom only 61% knew their HIV-positive status and only 62% were virally suppressed. There is pro-poor inequality in HIV care coverage, with those in lower socioeconomic groups more likely to be virally suppressed.