C44 vs C46.0
C44 and C46.0 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 C44
Kaposi's sarcoma of skin (C46.0)
C44
Other and unspecified malignant neoplasm of skin
Not billable
- Chapter 2
- Neoplasms
- Section
- C43-C44
Use when the record says
- malignant neoplasm of sebaceous glands
- malignant neoplasm of sweat glands
C46.0
Kaposi's sarcoma of skin
Billable
- Chapter 2
- Neoplasms
- Section
- C45-C49
Indexed under
- Kaposi's › sarcoma › skin
- Sarcoma › Kaposi's › skin (of)
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