C96.6
Billable codeUnifocal Langerhans-cell histiocytosis
The ICD-10 code for unifocal langerhans-cell histiocytosis is C96.6.
Clinical notes
Excludes1 (not coded here)
An Excludes1 note is a pure exclusion: the excluded condition and this code should never be reported together, because the two conditions cannot occur at the same time (e.g. a congenital form vs. an acquired form of the same disease).
Also known as
Alternate wording, synonyms, or specific conditions that fall under this code, listed to help confirm you've picked the right one.
- Eosinophilic granuloma
- Histiocytosis X, unifocal
- Histiocytosis X NOS
- Langerhans-cell histiocytosis NOS
Documentation support
General coding-documentation guidance — not a substitute for payer-specific requirements or professional coding judgment.
- •Confirm the excluded condition(s) listed above are not also present — Excludes1 conditions cannot be coded together with this one.
- •As a general rule, code to the highest level of specificity supported by the documentation in the medical record.
Related codes in this category
- C96.0Multifocal and multisystemic (disseminated) Langerhans-cell histiocytosis
- C96.2Malignant mast cell neoplasmnon-billable header
- C96.4Sarcoma of dendritic cells (accessory cells)
- C96.5Multifocal and unisystemic Langerhans-cell histiocytosis
- C96.9Malignant neoplasm of lymphoid, hematopoietic and related tissue, unspecified
- C96.AHistiocytic sarcoma
- C96.ZOther specified malignant neoplasms of lymphoid, hematopoietic and related tissue
- C96.6Unifocal Langerhans-cell histiocytosis
ICD-9-CM equivalent
Informational only — GEM mappings are approximate, not guaranteed one-to-one equivalents. Verify before use in billing.
- 27789Approximate match
Associated MS-DRGs
C96.6 can serve as the principal diagnosis for these Medicare Severity Diagnosis-Related Groups.
Informational only — actual DRG assignment also depends on procedures, complications/comorbidities (CC/MCC), discharge status, and payer-specific rules not reflected here.