Characteristics and risk factors of fee-for-service Medicaid patients (age < 65 yr) with high health care costs were assessed by analyzing Ohio's Medicaid claims database. High-cost recipients were defined as those with average monthly Medicaid expenses at or above the 90th percentile. The records of 10,582 high-cost patients and 11,045 comparison patients were examined for clinical comorbidity, mortality status, enrollment, and demographic factors, using logistic and logarithmic multiple regression. Researchers found that a Medicaid recipient had the greatest odds of being in the following groups: dying (odds ratio = 4.0), disabled (2.2), urban resident (1.8), and male (1.3). They concluded that state and federal efforts to control Medicaid expenditures should focus on those high-costrecipients and examine their service utilization.