Treatment of hyperglycemia in hospitalized patients reduces adverse clinical outcomes. When a patient with diabetes is admitted, HbA1c should be obtained. Antidiabetic medications usually must be modified. In general, this means using some form of insulin treatment to achieve moderate glycemic control while avoiding hypoglycemia. Frequent blood glucose testing and adjusting insulin treatment during hospitalization are required. Diabetes treatment at the time of discharge must be transitioned to a regimen that can be followed as an outpatient and reevaluated shortly afterward.