Although sickle cell disease (SCD) is marked by high utilization of medical resources, the full cost of care for patients with SCD, including care not directly related to SCD, is unknown. The purpose of this study was to estimate the total cost of medical care for a population of children and adults with SCD. We used data from individuals diagnosed with SCD enrolled in the Florida Medicaid program during 2001-2005 to estimate total, SCD-related, and non-SCD-related cost per patient-month based on patient age at the time of health care use. Across the 4,294 patient samples, total health care costs generally rose with age, from $892 to $2,562 per patient-month in the 0-9- and 50-64-year age groups, respectively. Average cost per patient-month was $1,389. Overall, 51.8% of care was directly related to SCD, the majority of which (80.5%) was associated with inpatient hospitalizations. Notably, non-SCD-related costs were substantially higher than those reported for the general US population. These results suggest a discounted (3% discount rate) lifetime cost of care averaging $460,151 per patient with SCD. Interventions designed to prevent SCD complications and avoid hospitalizations may reduce the significant economic burden of the disease.