C79.81 — Secondary malignant neoplasm of breast
Is C79.81 billable?
Yes — C79.81 is billable for FY2027. C79.81 is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. C79.81 may be submitted for encounters from October 1, 2026 through September 30, 2027.
C79.81 at a glance
| Code | C79.81 |
|---|---|
| Description | Secondary malignant neoplasm of breast |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Which MS-DRGs does C79.81 group to?
C79.81 sits in MDC 09 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 582Mastectomy for Malignancy with CC/MCCsurgical
- 583Mastectomy for Malignancy without CC/MCCsurgical
As a secondary diagnosis, C79.81 is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG.
How is C79.81 listed in the Alphabetic Index?
These are the routes through the Alphabetic Index that lead to C79.81. They show the wording a clinician may have documented, which often differs from the Tabular description.
- Melanoma › metastatic › breast (malignant)
Excludes1 — never code together — inherited from C79
The conditions below can never be reported together with C79.81 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
How long has C79.81 existed?
C79.81 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.