Is C78 a billable ICD-10-CM code?

No. C78 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does C78 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 C78?

C78 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.

C78

C78 — Secondary malignant neoplasm of respiratory and digestive organs

Non-billable headerICD-10-CM

C78 is a non-billable header ICD-10-CM code for secondary malignant neoplasm of respiratory and digestive organs. 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.

secondary carcinoid tumors of liver (C7B.02)
secondary carcinoid tumors of peritoneum (C7B.04)

Excludes2 — not included here, but may coexist

The excluded condition is not part of this code, but a patient can have both. You may code both.

lymph node metastases (C77.0)

Other codes that can never be billed with C78

These codes carry an Excludes1 note pointing at C78. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading C78 alone.

C22Malignant neoplasm of liver and intrahepatic bile ducts

Risk adjustment

C78 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 C78

9 child codes. Green means billable.

Questions about C78

Is C78 a billable ICD-10-CM code?: No. C78 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does C78 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 C78?: C78 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.