MS-DRG · FY 2026 v43.0

MS-DRG 188 – Pleural Effusion without CC/MCC

A Medical DRG in MDC 04 (Diseases & Disorders of the Respiratory System). Inpatient cases group to DRG 188 when the ICD-10-CM principal diagnosis is one of the 5 codes listed below and no secondary diagnosis on the CC or MCC lists is present. Its FY 2026 relative weight is 0.7172 with a geometric mean length of stay of 2.1 days.

Medical DRG – assigned by principal diagnosis✓ Official CMS v43.0 dataset
0.7172
Relative Weight
2.1
Geometric Mean LOS (days)
2.6
Arithmetic Mean LOS (days)
5
Principal Diagnosis Codes

Severity family

DRG 186with MCCWeight 1.5585 · GMLOS 4.2 daysDRG 187with CCWeight 0.9891 · GMLOS 3.0 daysDRG 188without CC/MCCWeight 0.7172 · GMLOS 2.1 days
How a case is assigned to DRG 188

The grouper first assigns the case to MDC 04 from the principal diagnosis and finds no qualifying operating-room procedure (this is a Medical DRG; ICD-10-PCS codes do not drive assignment here), then applies the severity split from secondary diagnoses: with MCC → 186; with CC → 187; without CC/MCC → 188.

ICD-10-CM

Principal Diagnosis Codes 5 codes · 3 categories

J90 Pleural effusion, not elsewhere classified1 code
  • J90 Pleural effusion, not elsewhere classified
J91 Pleural effusion in conditions classified elsewhere1 code
  • J91.8 Pleural effusion in other conditions classified elsewhere
J94 Other pleural conditions3 codes
  • J94.0 Chylous effusion
  • J94.2 Hemothorax
  • J94.8 Other specified pleural conditions
ICD-10-PCS

Procedure Codes

Procedure codes do not drive assignment for this DRG. DRG 188 is a Medical DRG, assigned from the principal diagnosis above.

Frequently Asked Questions

What is MS-DRG 188?

MS-DRG 188 (Pleural Effusion without CC/MCC) is a medical DRG in MDC 04 (Diseases & Disorders of the Respiratory System). Its FY 2026 relative weight is 0.7172 with a geometric mean length of stay of 2.1 days.

What is the difference between DRG 186, 187, 188?

All 3 share the same base category; the severity of secondary diagnoses separates them: 186 (with MCC), 187 (with CC), 188 (without CC/MCC). A major complication or comorbidity (MCC) places the case in the highest-weighted DRG of the family; a CC in the middle; neither in the lowest.

How many diagnosis codes group to DRG 188?

5 ICD-10-CM principal diagnosis codes group to this DRG, spanning 3 three-character categories.

What is the relative weight of DRG 188?

The FY 2026 relative weight of this DRG is 0.7172, meaning reimbursement of roughly 0.72 times the average Medicare inpatient case. Multiply by a hospital's blended base rate for the approximate payment.

← PreviousDRG 187 – Pleural Effusion with CC
Source: CMS ICD-10 MS-DRG v43.0 Definitions Manual and the FY 2026 IPPS Final Rule (Table 5), effective October 1, 2025 through September 30, 2026. We publish the DRG assignments as CMS defines them and add the navigation, search, and code links.