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MS-DRG v44.0 · MDC 18: Infectious and Parasitic Diseases, Systemic or Unspecified Sites

865 — Viral Illness with MCC

Relative weight
1.3485
Geometric mean LOS
3.7 days
Arithmetic mean LOS
5.1 days
Type
Medical

About MS-DRG 865

MS-DRG 865, Viral Illness with MCC, is a medical DRG in MDC 18 (Infectious and Parasitic Diseases, Systemic or Unspecified Sites) under MS-DRG version 44.0, which applies to inpatient discharges from October 1, 2026 through September 30, 2027.

Its FY2027 relative weight is 1.3485, so Medicare's base payment for this DRG is about 1.35 times the average inpatient case, before hospital-specific adjustments. The geometric mean length of stay is 3.7 days and the arithmetic mean is 5.1 days.

It belongs to a 2-level severity family: DRG 865 (with MCC, weight 1.3485) and DRG 866 (without MCC, weight 0.8692). The highest-severity level carries 1.6 times the weight of the lowest, which is why documenting CC and MCC conditions matters.

141 ICD-10-CM diagnosis codes are part of this DRG's grouping logic; they are listed below.

ICD-10-CM codes that group to DRG 865 (141)

Chapter 1: Certain infectious and parasitic diseases

Chapter 10: Diseases of the respiratory system

Chapter 12: Diseases of the skin and subcutaneous tissue

Chapter 19: Injury, poisoning and certain other consequences of external causes

Chapter 21: Factors influencing health status and contact with health services

Common questions about DRG 865

What is the relative weight of DRG 865?

1.3485 for FY2027 (MS-DRG v44.0), from the IPPS final rule Table 5.

What is the average length of stay for DRG 865?

The geometric mean length of stay is 3.7 days; the arithmetic mean is 5.1 days.

Is DRG 865 medical or surgical?

DRG 865 is a medical DRG.