Excludes1 pair
C71.5 vs C71.7
C71.5 and C71.7 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 C71.5
malignant neoplasm of fourth cerebral ventricle (C71.7)
C71.5
Malignant neoplasm of cerebral ventricle
Billable
- Chapter 2
- Neoplasms
- Section
- C69-C72
Indexed under
- Papilloma › choroid plexus › anaplastic
- Papilloma › choroid plexus › malignant
C71.7
Malignant neoplasm of brain stem
Billable
- Chapter 2
- Neoplasms
- Section
- C69-C72
Use when the record says
- Malignant neoplasm of fourth cerebral ventricle
- Infratentorial malignant neoplasm NOS
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