ICDcodes.org
FY2027

C38.0 vs C45.2

C38.0 and C45.2 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 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 (malignant)

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