ICD-10-CM 2027
ICD-10 code for Retroviral seroconversion acute syndrome
Asymptomatic human immunodeficiency virus [HIV] infection status
From the official ICD-10-CM alphabetic index entry “Syndrome › retroviral seroconversion (acute)”. Page updated September 29, 2026.
About coding Retroviral seroconversion acute syndrome
The ICD-10-CM code for Retroviral seroconversion acute syndrome is Z21 (Asymptomatic human immunodeficiency virus [HIV] infection status).
Don't report Z21 together with the conditions in its Excludes1 note: acquired immunodeficiency syndrome (B20), contact with human immunodeficiency virus [HIV] (Z20.6), exposure to human immunodeficiency virus [HIV] (Z20.6), human immunodeficiency virus [HIV] disease (B20) and 1 more.
Code first: Human immunodeficiency virus [HIV] disease complicating pregnancy, childbirth and the puerperium, if applicable (O98.7-).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
Don't confuse with (Excludes1 for Z21)
Common questions about Retroviral seroconversion acute syndrome ICD-10 codes
What is the ICD-10 code for Retroviral seroconversion acute syndrome?
- Z21 — Asymptomatic human immunodeficiency virus [HIV] infection status.
Is Z21 billable?
- Yes. Z21 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can Z21 be used as a principal diagnosis?
- It can, but When it is the principal diagnosis, Medicare considers it a questionable reason for an inpatient admission, so claims may be reviewed.
Is Z21 a CC or MCC?
- No. Z21 is neither a CC nor an MCC under MS-DRG v44.0.