Excludes1 pair
B00.9 vs B34-
B00.9 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
herpesvirus [herpes simplex] infection NOS (B00.9)
B00.9
Herpesviral infection, unspecified
BillableUnspecified
- Chapter 1
- Certain infectious and parasitic diseases
- Section
- B00-B09
Use when the record says
- Herpes simplex infection NOS
Indexed under
- Herpes, herpesvirus, herpetic
- Herpes, herpesvirus, herpetic › human
- Herpes, herpesvirus, herpetic › simplex
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