C96.20 — Malignant mast cell neoplasm, unspecified
C96.20 is a billable, specific ICD-10-CM code for malignant mast cell neoplasm, unspecified. It is valid for submission on a claim.
Excludes1 inherited from the categories above C96.20
These are not written on C96.20, but they bind it: a note on a category applies to every code beneath it. Billing C96.20 with anything listed here is a denial.
Written on C96.2 — Malignant mast cell neoplasm
Other codes that can never be billed with C96.20
These codes carry an Excludes1 note pointing at C96.20. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading C96.20 alone.
- C77Secondary and unspecified malignant neoplasm of lymph nodes
Risk adjustment
C96.20 risk-adjusts. Under the CMS-HCC V28 model it maps to this category:
- HCC 21 Lymphoma and Other Cancers0.671 RAF
Coefficient shown for the Community Non-dual Aged segment. A higher HCC in the same hierarchy will suppress this one, so capturing it does not always add score.
Medicare coverage
C96.20 is named in 34 Medicare coverage policies — 34 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A52370Billing and Coding: Bevacizumab and biosimilars
- A52986Billing and Coding: Biomarkers for Oncology
- A54768Billing and Coding: Cardiac Blood Pool Imaging (Multiple Gated Acquisition Scanning- MUGA, Ventriculography) When Performed in Conjunction with Cardiotoxic Chemotherapy
- A55717Billing and Coding: Lab: Flow Cytometry
How C96.20 is indexed
Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to C96.20.
- Neoplasm, neoplastic›malignant mast cell
- Mast cell›neoplasm›malignant
Code history
C96.20 has not changed since FY2024 — no addition, revision or deletion across the three most recent ICD-10-CM releases.
Related codes at this level
Codes that share C96.2. If C96.20 is not quite right, the correct code is usually one of these.
Questions about C96.20
- Is C96.20 a billable ICD-10-CM code?
- Yes. C96.20 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does C96.20 sit in the tabular list?
- Neoplasms (C00-D49), in the block Malignant neoplasms of lymphoid, hematopoietic and related tissue (C81-C96).
- What cannot be coded together with C96.20?
- C96.20 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above C96.20 (C96.2, C96) and apply to it just the same.