C79.81 – Secondary malignant neoplasm of breast

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

Billable code

ICD-10-CM code C79.81
Code
C79.81 (claims format: C7981)
Description
Secondary malignant neoplasm of breast
Billable
Yes – valid for HIPAA-covered transactions
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
Parent codes
C79 › C79.8

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

C79 – Secondary malignant neoplasm of other and unspecified sites

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

Index terms for C79.81

Entries in the ICD-10-CM alphabetic index that lead to this code:

Related codes in C79.8

Frequently asked questions

What is ICD-10 code C79.81?

C79.81 is the ICD-10-CM code for secondary malignant neoplasm of breast, in the block C76-C80 (Malignant neoplasms of ill-defined, other secondary and unspecified sites).

Is C79.81 a billable code?

Yes. C79.81 is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.

What category does C79.81 belong to?

It belongs to category C79 – Secondary malignant neoplasm of other and unspecified sites.

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.