To the Editor.— Medicare initiated the transition to diagnosis related groups (DRGs) for hospital inpatient reimbursement in 1983. If DRGs successfully control Medicare's hospital costs, other reimbursers may adopt DRG payment for all inpatients. Diagnosis related groups have generated clamorous debate, yet few physicians are familiar with the costs or prevalence rates of different DRG categories. Tables 1 and 2 present the ten most common and the ten most expensive DRGs for all nonfederal short-stay hospital admissions in 1985, based on the National Hospital Discharge Survey (NHDS) and the Maryland Health Services Cost Review Commission (HSCRC).1,2The NHDS abstracts inpatient medical records from a national sample of nonfederal short-stay hospitals and classifies each admission by the DRG code published in the Aug 31, 1984, issue of theFederal Register.3The HSCRC collects data from all nonfederal short-stay Maryland hospitals, classifies each admission by the DRG code published in