Is C80.1 a billable ICD-10-CM code?

Yes. C80.1 is a billable, specific ICD-10-CM code and is valid for submission on a claim.

Where does C80.1 sit in the tabular list?

Neoplasms (C00-D49), in the block Malignant neoplasms of ill-defined, other secondary and unspecified sites (C76-C80).

What cannot be coded together with C80.1?

C80.1 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 C80.1 (C80) and apply to it just the same.

C80.1

C80.1 — Malignant (primary) neoplasm, unspecified

Billable / specific codeICD-10-CM

C80.1 is a billable, specific ICD-10-CM code for malignant (primary) neoplasm, unspecified. It is valid for submission on a claim.

Excludes1 — never code together

These conditions cannot occur together. Billing both on the same encounter is a denial.

secondary malignant neoplasm of unspecified site (C79.9)

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

Cancer NOS
Cancer unspecified site (primary)
Carcinoma unspecified site (primary)
Malignancy unspecified site (primary)

Excludes1 inherited from the categories above C80.1

These are not written on C80.1, but they bind it: a note on a category applies to every code beneath it. Billing C80.1 with anything listed here is a denial.

Written on C80 — Malignant neoplasm without specification of site

malignant carcinoid tumor of unspecified site (C7A.00)
malignant neoplasm of specified multiple sites- code to each site

Other codes that can never be billed with C80.1

These codes carry an Excludes1 note pointing at C80.1. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading C80.1 alone.

C76Malignant neoplasm of other and ill-defined sites
C79.9Secondary malignant neoplasm of unspecified site

Risk adjustment

C80.1 risk-adjusts. Under the CMS-HCC V28 model it maps to this category:

HCC 23 Prostate, Breast, and Other Cancers and Tumors0.186 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

C80.1 is named in 56 Medicare coverage policies — 56 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

A52450Billing and Coding: Paclitaxel (e.g., Taxol®/Abraxane ™)
A52479Oral Anticancer Drugs - Policy Article
A52479Oral Anticancer Drugs - Policy Article
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How C80.1 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 C80.1.

Cancer›unspecified site(primary)
Carcinoma›unspecified site(primary)
Malignancy›unspecified site(primary)
Sarcomatosis›unspecified site
Tumor›malignant
Tumor›malignant›fusiform cell(type)
Tumor›malignant›giant cell(type)
Tumor›malignant›mixed NEC
Tumor›malignant›small cell(type)
Tumor›malignant›spindle cell(type)
Tumor›malignant›unclassified

Code history

C80.1 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 C80. If C80.1 is not quite right, the correct code is usually one of these.

Questions about C80.1

Is C80.1 a billable ICD-10-CM code?: Yes. C80.1 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does C80.1 sit in the tabular list?: Neoplasms (C00-D49), in the block Malignant neoplasms of ill-defined, other secondary and unspecified sites (C76-C80).
What cannot be coded together with C80.1?: C80.1 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 C80.1 (C80) and apply to it just the same.