2026 ICD-10-CM Diagnosis Code C96.AHistiocytic sarcoma
ICD-10-CM Codes›C00–D49›C81-C96›C96
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Risk Adjusts — HCC 21
- Chronic Condition
C96.A is a billable ICD-10-CM diagnosis code for histiocytic sarcoma. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 11 through 13, 820 through 825, 840 through 842. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 47 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Sarcoma.
For Medicare Advantage risk adjustment, C96.A maps to CMS-HCC Category 21 (Lymphoma and Other Cancers) under the V28 model, adding a risk factor of about 0.671 for a community, non-dual, aged beneficiary in payment year 2026.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
C96.A maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2026.
Source: CMS Payment Year 2026 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Fibroblastic reticular cell neoplasm
- Histiocytic sarcoma
- Malignant histiocytic disorder
- Malignant histiocytosis
- Malignant histiocytosis involving skin
- Malignant histiocytosis of intra-abdominal lymph nodes
- Malignant histiocytosis of intrapelvic lymph nodes
- Malignant histiocytosis of intrathoracic lymph nodes
- Malignant histiocytosis of lymph nodes of axilla and upper limb
- Malignant histiocytosis of lymph nodes of head
- Malignant histiocytosis of lymph nodes of head and neck
- Malignant histiocytosis of lymph nodes of lower limb
- Malignant histiocytosis of lymph nodes of multiple sites
- Malignant histiocytosis of lymph nodes of neck
- Malignant histiocytosis of lymph nodes of upper limb
- Malignant histiocytosis of spleen
- Neoplasm of intra-abdominal lymph nodes
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Malignant histiocytosis
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Arthropathy See Also: Arthritis; M12.9
malignant C96.A
Lymphoma (of) (malignant) C85.90
true C96.A
true histiocytic C96.A
Sarcoma (of) See Also: Neoplasm, connective tissue, malignant;
histiocytic C96.A
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Histiocytic Sarcoma
malignant neoplasms composed of macrophages or dendritic cells. most histiocytic sarcomas present as localized tumor masses without a leukemic phase. though the biological behavior of these neoplasms resemble lymphomas, their cell lineage is histiocytic not lymphoid.
Convert C96.A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About C96.AOverview
What is the ICD-10 code for histiocytic sarcoma?
The ICD-10-CM code for histiocytic sarcoma is C96.A (sometimes written as C96A). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is C96.A a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report histiocytic sarcoma on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does C96.A group to?
When histiocytic sarcoma is the principal diagnosis on an inpatient stay, it groups to MS-DRG 11, 12, 13, 820, 821, 822, 823, 824, 825, 840, 841, 842, with relative weights from 1.0104 to 5.8648 depending on complications. Higher weights mean higher Medicare reimbursement.
Is C96.A a CC or MCC?
CMS lists C96.A as a CC (complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 47 closely related codes in its exclusion list.
What is the ICD-9 equivalent of C96.A?
Under the General Equivalence Mappings, histiocytic sarcoma converts to ICD-9-CM 202.30 (mlg hist unsp xtrndl org). The mapping is approximate, so confirm the match fits the documentation.
What HCC is C96.A?
C96.A (histiocytic sarcoma) maps to CMS-HCC Category 21 (Lymphoma and Other Cancers), commonly written as HCC 21, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2026. It mapped to HCC 10 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 21.
Does C96.A risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, C96.A adds a risk adjustment factor of about 0.671 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.493 to 0.739 depending on the payment segment). A more severe related category (HCC 17, HCC 18, HCC 19, and HCC 20) supersedes it when both are reported. See the full factor table on the HCC 21 category page.
