Excludes1 pair
B40- vs B48.0
B40 and B48.0 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 B40
keloidal blastomycosis (B48.0)
B48.0
Lobomycosis
Billable
- Chapter 1
- Certain infectious and parasitic diseases
- Section
- B35-B49
Use when the record says
- Keloidal blastomycosis
- Lobo's disease
Indexed under
- Lobomycosis
- Lobo's disease
- Blastomycosis, blastomycotic › keloidal
- Disease, diseased › Lobo's (keloid blastomycosis)
- Infection, infected, infective › glenosporopsis
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