Is C77 a billable ICD-10-CM code?

No. C77 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does C77 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 C77?

C77 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.

C77

C77 — Secondary and unspecified malignant neoplasm of lymph nodes

Non-billable headerICD-10-CM

C77 is a non-billable header ICD-10-CM code for secondary and unspecified malignant neoplasm of lymph nodes. 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 neoplasm of lymph nodes, specified as primary (C81-C86, C88, C96.-)
mesentery metastasis of carcinoid tumor (C7B.04)
secondary carcinoid tumors of distant lymph nodes (C7B.01)

Risk adjustment

C77 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 C77

8 child codes. Green means billable.

Questions about C77

Is C77 a billable ICD-10-CM code?: No. C77 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does C77 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 C77?: C77 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.