Excludes1 pair
C30.1 vs C41.0
C30.1 and C41.0 are not coded together. ICD-10-CM declares them mutually exclusive with an Excludes1 note — the two conditions are not expected to occur together, so exactly one of them is normally correct for a given encounter. The Official Guidelines carve out one exception: if the two conditions are clearly unrelated to each other, both may be reported.
The official note, declared on C30.1
malignant neoplasm of bone of ear (meatus) (C41.0)
C30.1
Malignant neoplasm of middle ear
Billable
- Chapter 2
- Neoplasms
- Section
- C30-C39
Use when the record says
- Malignant neoplasm of antrum tympanicum
- Malignant neoplasm of auditory tube
- Malignant neoplasm of eustachian tube
- Malignant neoplasm of inner ear
- Malignant neoplasm of mastoid air cells
- Malignant neoplasm of tympanic cavity
C41.0
Malignant neoplasm of bones of skull and face
Billable
- Chapter 2
- Neoplasms
- Section
- C40-C41
Use when the record says
- Malignant neoplasm of maxilla (superior)
- Malignant neoplasm of orbital bone
Indexed under
- Odontosarcoma, ameloblastic › upper jaw (bone)
- Carcinoma › ameloblastic › upper jaw (bone)
- Carcinoma › intraosseous › upper jaw (bone)
- Carcinoma › odontogenic › upper jaw (bone)
- Fibrosarcoma › ameloblastic › upper jaw (bone)
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