Excludes1 pair
B25.9 vs B34-
B25.9 and B34 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 B34
cytomegaloviral disease NOS (B25.9)
B25.9
Cytomegaloviral disease, unspecified
BillableUnspecified
- Chapter 1
- Certain infectious and parasitic diseases
- Section
- B25-B34
Indexed under
- Cytomegalovirus infection
- Disease, diseased › cytomegalic inclusion (generalized)
- Disease, diseased › cytomegaloviral
- Disease, diseased › inclusion
- Infection, infected, infective › cytomegalovirus, cytomegaloviral
B34
Viral infection of unspecified site
Not billable
- Chapter 1
- Certain infectious and parasitic diseases
- Section
- B25-B34
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