Excludes1 pair
C94- vs D47.4
C94 and D47.4 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 D47.4
acute myelofibrosis (C94.4-)
D47.4
Osteomyelofibrosis
Billable
- Chapter 2
- Neoplasms
- Section
- D37-D48
Use when the record says
- Chronic idiopathic myelofibrosis
- Myelofibrosis (idiopathic) (with myeloid metaplasia)
- Myelosclerosis (megakaryocytic) with myeloid metaplasia
- Secondary myelofibrosis in myeloproliferative disease
Indexed under
- Osteomyelofibrosis
- Myelofibrosis › with myeloid metaplasia
- Myelofibrosis › idiopathic (chronic)
- Myelosclerosis › with myeloid metaplasia
- Myelosclerosis › megakaryocytic
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