Answer: A. 1 of 25 Major Diagnostic Categories (MDCs).
A Diagnosis-Related Group (DRG) is a statistical system in which inpatients are classified according to possible diagnoses, for the purposes of payment. The DRG system classifies diagnoses into 25 diagnostic categories and subdivides them into almost 500 groups. One MS-DRG is assigned to each inpatient stay. Based on this principal diagnosis, an inpatient is assigned one MS-DRG code.
