MS-DRGs, Case Mix & Clinical Documentation Integrity
How the grouper assigns MS-DRGs, CC/MCC tiers and exclusions, common CC/MCC conditions, APR-DRGs, quality indicators, and the CDI specialist's role.
How a DRG is assigned
Slide 1 / 5
1. The principal diagnosis assigns a Major Diagnostic Category (MDC) — mostly by body system (MDC 4 respiratory, MDC 5 circulatory…).
2. If an operating room procedure was performed → a surgical DRG; otherwise a medical DRG.
3. Secondary diagnoses that are CCs or MCCs move the case into a higher tier.
4. Discharge status, age and some special conditions can also change it.
Many DRGs come in families: e.g. Simple pneumonia and pleurisy — 193 with MCC, 194 with CC, 195 without CC/MCC.