C96.20

✓ Billable

Malignant mast cell neoplasm, unspecified

Neoplasms (C00-D49)

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❌ Excludes1

inherited

Rules inherited from parent codes in the hierarchy.

C96.2

• indolent mastocytosis (D47.02)
• mast cell leukemia (C94.30)
• mastocytosis (congenital) (cutaneous) (Q82.2)

C96

• personal history of other malignant neoplasms of lymphoid, hematopoietic and related tissues (Z85.79)

Clinical Description

ICD-10-CM code C96.20 represents malignant mast cell neoplasm, unspecified. This code falls under the Neoplasms (C00-D49) classification. It is a billable/specific code valid for HIPAA-covered transactions as of October 1, 2025 (FY2026). This code can be used to indicate a diagnosis for reimbursement purposes on insurance claims.

This is a 6-character code at the 5th level of specificity. This is the most specific code available in this subcategory. Coders should note that C96.20 has 4 Excludes1 restriction(s) — codes that cannot be reported together on the same claim.

Frequently Asked Questions

What is ICD-10 code C96.20?

ICD-10-CM code C96.20 is "Malignant mast cell neoplasm, unspecified". It belongs to the category: Neoplasms (C00-D49).

Is C96.20 a billable ICD-10 code?

Yes, C96.20 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.

What codes are excluded with C96.20?

C96.20 has 4 Excludes1 rule(s). These codes are mutually exclusive and cannot be coded together on the same claim.

Related Codes in C96.2

Other codes in the same category that may be relevant for differential coding:

C96.21Aggressive systemic mastocytosis C96.22Mast cell sarcoma C96.29Other malignant mast cell neoplasm

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Code Information

CodeC96.20

BillableYes

ParentC96.2

CategoryNeoplasms (C00-D49)

Excludes14 rule(s)

Excludes20 note(s)

Data Source

CMS ICD-10-CM 2026 Tabular List

Updated October 1, 2025 (FY2026)