An MS-DRG relative weight represents relative expected resource consumption, not a direct severity score or mortality probability. Therefore, a relative weight of approximately 2.0 means the MS-DRG is associated with roughly twice the resource intensity of the average case represented by the standardized reference point.

CMS calculates and recalibrates MS-DRG relative weights using national hospital data as part of IPPS rate setting. The FY 2026 final-rule materials include the MS-DRG weighting factors as well as supporting cost data used in the relative-weight methodology.

Clinically complex cases often consume more resources, so relative weight may correlate with severity. However, it is not equivalent to a patient's severity-of-illness score or risk-of-mortality score. Likewise, hospitals do not simply multiply their billed charges based on the DRG weight. IPPS payment involves the standardized amount plus various adjustments, including wage index and other applicable payment factors.

For CDI, accurate documentation matters because diagnoses and procedures drive MS-DRG assignment, and the assigned MS-DRG carries its specific relative weight.

CCDS Reference Topics: IPPS; MS-DRG relative weight; resource consumption; reimbursement methodology.

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