C76 vs C80.1
C76 and C80.1 can never be reported together. ICD-10-CM declares them mutually exclusive with an Excludes1 note, meaning the two conditions cannot occur in the same patient — so exactly one of them is correct for any given encounter.
The official note, declared on C76
malignant neoplasm of unspecified site NOS (C80.1)
C80.1
Malignant (primary) neoplasm, unspecified
BillableUnspecified
- Chapter 2
- Neoplasms
- Section
- C76-C80
Use when the record says
- Cancer NOS
- Cancer unspecified site (primary)
- Carcinoma unspecified site (primary)
- Malignancy unspecified site (primary)
Indexed under
- Cancer › unspecified site
- Carcinoma › unspecified site (malignant)
- Malignancy › unspecified site
- Sarcomatosis › unspecified site
- Tumor › malignant
Excludes1 is not always absolute: where two conditions covered by the note are genuinely unrelated, CMS guidance permits reporting both. Document the reasoning rather than assuming it. More on Excludes1 vs Excludes2 · FY2027