This file contains hospitals case mix indexes (CMI) for discharges. A hospital's CMI represents the average diagnosis-related group (DRG) relative weight for that hospital. It is calculated by summing the DRG weights for all Medicare discharges and dividing by the number of discharges. CMIs are calculated using both transfer-adjusted cases and unadjusted cases. We intend to update the case mix index at this website annually to coincide with the proposed and final updates to the IPPS.