C80.1 — Malignant (primary) neoplasm, unspecified
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)
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.
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 52 Medicare coverage policies — 52 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
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- 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
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 an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.