INTRODUCTION: Recent studies project thousands of additional AIDS-related deaths because of COVID-19-related disruptions in HIV care. However, the extent to which disruptions in care have materialized since the start of the pandemic is not well understood. METHODS: We use electronic health records to investigate how the pandemic has affected clinic visits, patients' antiretroviral therapy (ART) supply, and viral suppression for a cohort of 14,632 HIV clients from a large HIV clinic in Kampala, Uganda. We complement this with an analysis of electronically measured longitudinal ART adherence data from a subcohort of 324 clients. RESULTS: Clinic visits decreased by more than 50% after a national lockdown started. The risk of patients running out of ART on a given day increased from 5% before the lockdown to 25% 3 months later (Relative Risk Ratio of 5.11, 95% confidence interval: 4.99 to 5.24) and remained higher than prelockdown 6 months later at 13% (Relative Risk Ratio of 2.60; 95% confidence interval: 2.52 to 2.70). There was no statistically significant change in electronically measured adherence or viral suppression. CONCLUSION: We document substantial gaps in HIV care after the start of the COVID-19 pandemic in Uganda. This suggests that measures to improve access should be explored as the pandemic persists. However, ART adherence was unaffected for the subcohort for whom we measured electronic adherence. This suggests that some clients may have stockpiles of ART tablets from previous prescriptions that allowed them to keep taking their medication even when they could not visit the clinic for ART refills.