C00.2 vs C43.0
C00.2 and C43.0 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 C43.0
malignant neoplasm of vermilion border of lip (C00.0-C00.2)
C00.2
Malignant neoplasm of external lip, unspecified
BillableUnspecified
- Chapter 2
- Neoplasms
- Section
- C00-C14
Use when the record says
- Malignant neoplasm of vermilion border of lip NOS
C43.0
Malignant melanoma of lip
Billable
- Chapter 2
- Neoplasms
- Section
- C43-C44
Indexed under
- Melanoma › skin › lip (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