Excludes1 pair
Z20.6 vs Z21
Z20.6 and Z21 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 Z20.6
HIV infection status (Z21)
Z20.6
Contact with and (suspected) exposure to human immunodeficiency virus [HIV]
Billable
- Chapter 21
- Factors influencing health status and contact with health services
- Section
- Z20-Z29
Indexed under
- Contact › AIDS virus
- Contact › HIV
- Contact › HTLV-III/LAV
- Contact › human immunodeficiency virus (HIV)
- Exposure › AIDS virus
Z21
Asymptomatic human immunodeficiency virus [HIV] infection status
Billable
- Chapter 21
- Factors influencing health status and contact with health services
- Section
- Z20-Z29
Use when the record says
- HIV positive NOS
Indexed under
- HIV › positive, seropositive
- Status › human immunodeficiency virus infection, asymptomatic (HIV)
- Syndrome › retroviral seroconversion (acute)
- Syndrome › seroconversion, retroviral (acute)
- Human › immunodeficiency virus › asymptomatic status
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