2026 ICD-10-CM Diagnosis Code M31.31Wegener's granulomatosis with renal involvement

ICD-10-CM Codes›M00–M99›M30-M36›M31

ICD-10-CM M31.31
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M31.31 is a billable ICD-10-CM diagnosis code for Wegener's granulomatosis with renal involvement. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 542 through 544. Coders also document this condition as glomerulonephritis due to granulomatosis with polyangiitis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Systemic lupus erythematosus and connective tissue disorders and Vasculitis.

Code Identity

ICD-10-CM Code
M31.31
Billable Status
Yes — Valid for Submission
Code Describes
Wegener's granulomatosis with renal involvement
Short Description
Wegener's granulomatosis with renal involvement
Same as the full description in the CMS dataset.
Parent Code
M31.3
Wegener's granulomatosis

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM30-M36Systemic connective tissue disorders
CategoryM31Other necrotizing vasculopathies
This CodeM31.31Wegener's granulomatosis with renal involvement

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Glomerulonephritis due to granulomatosis with polyangiitis

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Disorder(of)
      • glomerular (in)
        • Wegener's granulomatosis
    • Glomerulonephritis
      • in (due to)
        • Wegener's granulomatosis
    • Granulomatosis
      • Wegener's
        • with renal involvement
    • Syndrome
      • Wegener's
        • with
          • kidney involvement
    • Syndrome
      • Wegener's
        • with
          • lung involvement
            • with kidney involvement
    • Wegener's granulomatosis or syndrome
      • with
        • kidney involvement
    • Wegener's granulomatosis or syndrome
      • with
        • lung involvement
          • with kidney involvement

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR MUS024
Systemic lupus erythematosus and connective tissue disorders
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR CIR037
Vasculitis
Default principal diagnosis: inpatient No · outpatient No

Patient EducationClinical

Granulomatosis with Polyangiitis

Granulomatosis with polyangiitis (GPA), previously known as Wegener's granulomatosis, is a rare disease. It is a type of vasculitis, or inflammation of the blood vessels. The inflammation limits the flow of blood to important organs, causing damage.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert M31.31 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
446.4 Wegener's granulomatosis
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About M31.31Overview

Is M31.31 (Wegener's granulomatosis) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report Wegener's granulomatosis with renal involvement on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does M31.31 group to?

When Wegener's granulomatosis with renal involvement is the principal diagnosis on an inpatient stay, it groups to MS-DRG 542, 543, 544, with relative weights from 0.7546 to 1.7665 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of M31.31?

Under the General Equivalence Mappings, Wegener's granulomatosis with renal involvement converts to ICD-9-CM 446.4 (Wegener's granulomatosis). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.