Is C80 a billable ICD-10-CM code?

No. C80 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does C80 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?

C80 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.

C80

C80 — Malignant neoplasm without specification of site

Non-billable headerICD-10-CM

C80 is a non-billable header ICD-10-CM code for malignant neoplasm without specification of site. It cannot be billed on its own: choose one of the more specific child codes below.

Excludes1 — never code together

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

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

These codes carry an Excludes1 note pointing at C80. 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 alone.

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

Risk adjustment

C80 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Code to one of these instead C80

3 child codes. Green means billable.

Questions about C80

Is C80 a billable ICD-10-CM code?: No. C80 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does C80 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?: C80 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.