P37 vs Z21
P37 (Other congenital infectious and parasitic diseases) compared with Z21 (Asymptomatic human immunodeficiency virus [HIV] infection status), from the official CMS tabular data. Both may be reported when both conditions are documented (Excludes2).
Can these codes be reported together?
Yes, when both are documented. P37 carries an Excludes2 note covering Z21: “asymptomatic human immunodeficiency virus [HIV] infection status (Z21)”
Excludes2 marks distinct conditions — both may be reported when both are documented.
Side by side
| P37Other congenital infectious and parasitic diseases | Z21Asymptomatic human immunodeficiency virus [HIV] infection status | |
|---|---|---|
| Billing status | Non-billable header | Billable |
| Classification | P00-P96 — Certain Conditions Originating in the Perinatal Period (P00-P96) | Z00-Z99 — Factors Influencing Health Status and Contact with Health Services (Z00-Z99) |
| Definition | Other congenital infectious and parasitic diseases is a non-billable ICD-10-CM category code (P37). | Asymptomatic human immunodeficiency virus [HIV] infection status is a billable ICD-10-CM diagnosis code (Z21). |
| Includes | — | HIV positive NOS |
| Code first | — | Human immunodeficiency virus [HIV] disease complicating pregnancy, childbirth and the puerperium, if applicable (O98.7-) |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources