2026 ICD-10-CM Diagnosis Code M31.2Lethal midline granuloma

ICD-10-CM Codes›M00–M99›M30-M36›M31

ICD-10-CM M31.2
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M31.2 is a billable ICD-10-CM diagnosis code for lethal midline granuloma. 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 extranodal NK/T-cell lymphoma, nasal type. 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
M31.2
Billable Status
Yes — Valid for Submission
Code Describes
Lethal midline granuloma
Short Description
Lethal midline granuloma
Same as the full description in the CMS dataset.
Parent Code
M31
Other necrotizing vasculopathies

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM30-M36Systemic connective tissue disorders
CategoryM31Other necrotizing vasculopathies
This CodeM31.2Lethal midline granuloma

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Extranodal NK/T-cell lymphoma, nasal type
  • Lethal midline granuloma

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.

    • Granuloma
      • gangraenescens
    • Granuloma
      • lethal midline (faciale (e))
    • Granuloma
      • malignant (facial (e))
    • Granuloma
      • midline (lethal)

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

Head and Neck Cancer

Head and neck cancer is the name for cancers that develop in the mouth, nose and sinuses, salivary glands, and throat and voice box (larynx). Most head and neck cancers are squamous cell cancers. They begin in the moist tissues that line the head and neck. The cancer cells may spread into deeper tissue as the cancer grows.

The full article covers:

  • What is head and neck cancer?
  • Who is more likely to develop head and neck cancer?
  • What are the symptoms of head and neck cancer?
  • How is head and neck cancer diagnosed?
  • What are the treatments for head and neck cancer?
  • Can head and neck cancer be prevented?

Read the full article at MedlinePlus

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

Convert M31.2 to ICD-9-CMHistory

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

ICD-9-CM
446.3 Lethal midline granuloma
Exact Match The mapping is direct, with no qualifiers.

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 M31.2Overview

Is M31.2 (Other necrotizing vasculopathies) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report lethal midline granuloma on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does M31.2 group to?

When lethal midline granuloma 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 M31.2?

Under the General Equivalence Mappings, lethal midline granuloma converts to ICD-9-CM 446.3 (lethal midline granuloma). The mapping is a direct match.

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.