Excludes1 pair
C38.4 vs C45.0
C38.4 and C45.0 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 C45.0
other malignant neoplasm of pleura (C38.4)
C45.0
Mesothelioma of pleura
Billable
- Chapter 2
- Neoplasms
- Section
- C45-C49
Indexed under
- Mesothelioma › site classification › pleura
- Mesothelioma › site classification › pleura › parietal
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