Excludes1 pair
C38.0 vs C45.2
C38.0 and C45.2 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 C45.2
other malignant neoplasm of pericardium (C38.0)
C38.0
Malignant neoplasm of heart
Billable
- Chapter 2
- Neoplasms
- Section
- C30-C39
Use when the record says
- Malignant neoplasm of pericardium
C45.2
Mesothelioma of pericardium
Billable
- Chapter 2
- Neoplasms
- Section
- C45-C49
Indexed under
- Mesothelioma › site classification › pericardium
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