R75 vs Z21
R75 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.
Inconclusive laboratory evidence of human immunodeficiency virus [HIV]
- Chapter 18
- Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
- Section
- R70-R79
- Nonconclusive HIV-test finding in infants
- HIV › laboratory evidence
- HIV › nonconclusive test
- Positive › test, human immunodeficiency virus
- Human › immunodeficiency virus › laboratory evidence
- Test, tests, testing › HIV › nonconclusive (for)
Asymptomatic human immunodeficiency virus [HIV] infection status
- Chapter 21
- Factors influencing health status and contact with health services
- Section
- Z20-Z29
- HIV positive NOS
- HIV › positive, seropositive
- Status › human immunodeficiency virusinfection, asymptomatic (post)
- Syndrome › retroviral seroconversion
- Syndrome › seroconversion, retroviral
- Human › immunodeficiency virus › asymptomatic status
These two codes sit in different chapters of the Tabular List, which is usually the clearest signal that they describe different underlying processes rather than different degrees of the same one.
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