D15.0 vs D21.3
D15.0 and D21.3 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 D21.3
benign neoplasm of thymus (D15.0)
D15.0
Benign neoplasm of thymus
Billable
- Chapter 2
- Neoplasms
- Section
- D10-D36
Indexed under
- Thymoma › microscopic
D21.3
Benign neoplasm of connective and other soft tissue of thorax
Billable
- Chapter 2
- Neoplasms
- Section
- D10-D36
Use when the record says
- Benign neoplasm of axilla
- Benign neoplasm of diaphragm
- Benign neoplasm of great vessels
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