Many DRGs are in “families” that differ by severity. There are three levels of severity: (1) MCC—Major Complication/

Comorbidity, which reflects the highest level of severity; (2) CC—Complication/Comorbidity, which is the next level of severity; and (3) Non-CC—Non-Complication/Comorbidity, which do not significantly affect severity of illness and resource use. The DRG that has the MCC is usually paid at a higher rate. What can cause a DRG without MCC to be changed to a DRG with MCC?