C79 – Secondary malignant neoplasm of other and unspecified sites

ICD-10-CM 2027 diagnosis code · Malignant neoplasms of ill-defined, other secondary and unspecified sites

Non-billable header

ICD-10-CM code C79
Code
C79 (claims format: C79)
Description
Secondary malignant neoplasm of other and unspecified sites
Billable
No – use a more specific code below
Valid for
Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter
2. Neoplasms (C00-D49)
Block
C76-C80 Malignant neoplasms of ill-defined, other secondary and unspecified sites

Billable codes under C79

C79 is a header code and cannot be used on claims. Choose the most specific code:

Notes for C79

Excludes1 (not coded here):
  • secondary carcinoid tumors (C7B.-)
  • secondary neuroendocrine tumors (C7B.-)

Frequently asked questions

What is ICD-10 code C79?

C79 is the ICD-10-CM code for secondary malignant neoplasm of other and unspecified sites, in the block C76-C80 (Malignant neoplasms of ill-defined, other secondary and unspecified sites).

Is C79 a billable code?

No. C79 is a header code with more specific child codes; report one of the billable codes listed above.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.