2026 ICD-10-CM Diagnosis Code C96.5Multifocal and unisystemic Langerhans-cell histiocytosis

ICD-10-CM CodesC00–D49C81-C96C96

ICD-10-CM C96.5
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

C96.5 is a billable ICD-10-CM diagnosis code for multifocal and unisystemic Langerhans-cell histiocytosis. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). Coders also document this condition as bone xanthoma. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Non-Hodgkin lymphoma.

Code Identity

ICD-10-CM Code
C96.5
Billable Status
Yes — Valid for Submission
Code Describes
Multifocal and unisystemic Langerhans-cell histiocytosis
Short Description
Multifocal and unisystemic Langerhans-cell histiocytosis
Same as the full description in the CMS dataset.
Parent Code
Other and unspecified malignant neoplasms of lymphoid, hematopoietic and related tissue

Code Classification

ChapterC00–D49Neoplasms
SectionC81-C96Malignant neoplasms of lymphoid, hematopoietic and related tissue
CategoryC96Other and unspecified malignant neoplasms of lymphoid, hematopoietic and related tissue
This CodeC96.5Multifocal and unisystemic Langerhans-cell histiocytosis

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Bone xanthoma

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Hand-Schüller-Christian disease
  • Histiocytosis X, multifocal

Type 1 Excludes

  • multifocal and multisystemic disseminated Langerhans-cell histiocytosis C96.0
  • unifocal Langerhans-cell histiocytosis C96.6

Index to Diseases and InjuriesGuidance

External Cause of Injuries IndexGuidance

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

    • Hand-Schüller-Christian disease or syndrome
    • Histiocytosis
      • Langerhans' cell NEC
        • multifocal X
          • unisystemic
    • Histiocytosis
      • X NEC
        • multifocal
    • Schüller-Christian disease or syndrome
    • Syndrome
      • Schüller-Christian
    • Xanthoma(s), xanthomatosis (primary) (familial) (hereditary)
      • bone (generalisata)

Clinical ClassificationClinical

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

CCSR NEO058
Non-Hodgkin lymphoma
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Langerhans cell histiocytosis

Langerhans cell histiocytosis is a disorder in which excess immune system cells called Langerhans cells build up in the body. Langerhans cells, which help regulate the immune system, are normally found throughout the body, especially in the skin, lymph nodes, spleen, lungs, liver, and bone marrow.

Read the full article at MedlinePlus

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

Convert C96.5 to ICD-9-CMHistory

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

ICD-9-CM
277.89 Metabolism disorder NEC
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 C96.5Overview

Is C96.5 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report multifocal and unisystemic Langerhans-cell histiocytosis on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What is the ICD-9 equivalent of C96.5?

Under the General Equivalence Mappings, multifocal and unisystemic Langerhans-cell histiocytosis converts to ICD-9-CM 277.89 (metabolism disorder NEC). 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.