The COVID-19 pandemic profoundly disrupted chronic disease management, including diabetes care. While early studies described short-term changes in access to care and laboratory monitoring, the long-term evolution of diabetes care delivery remains poorly understood. This study evaluates four-year longitudinal shifts in healthcare utilization, telemedicine adoption, preventive screening, pharmacologic treatment, and metabolic outcomes before and during the pandemic. We conducted a retrospective cohort study of adults with diabetes or prediabetes receiving care at a single health system from March 2018 to February 2022. Outcomes included primary care engagement, telemedicine use, adherence to ophthalmology and podiatry screening, medication prescribing patterns, HbA1c, BMI, urinary albumin–creatinine ratio (uACR), and mortality. A COVID-19–positive subgroup was analyzed separately. A sensitivity analysis was conducted restricting the cohort to patients with confirmed diabetes mellitus only (HbA1c ≥ 6.5
