Z20.6 vs Z21
Z20.6 and Z21 can never be reported together. ICD-10-CM declares them mutually exclusive with an Excludes1 note, meaning the two conditions cannot occur in the same patient — so exactly one of them is correct for any given encounter.
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 (with)
- Contact › HIV (with)
- Contact › HTLV-III/LAV (with)
- Contact › human immunodeficiency virus (with)
- Exposure › AIDS virus (to)
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 virusinfection, asymptomatic (post)
- Syndrome › retroviral seroconversion
- Syndrome › seroconversion, retroviral
- 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