O23
Non-Billable (Header)Infections of genitourinary tract in pregnancy
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
What This Code Means
O23 is the ICD-10-CM diagnosis code for infections of genitourinary tract in pregnancy. O23 sits in the ICD-10-CM chapter for pregnancy, childbirth and the puerperium (o00-o9a), within the section covering other maternal disorders predominantly related to pregnancy (o20-o29).
Header codes like O23 cannot be reported on claims directly — they organize child codes that share clinical context but the actual diagnosis must be coded to the highest level of specificity supported by the documentation. Coders should look at O23's child codes and select the one that matches the patient's documented presentation, since payers reject header codes submitted as the primary diagnosis. For risk adjustment workflows, header codes never contribute to a Medicare Advantage member's RAF score on their own; only billable child codes that happen to map to a payment HCC affect risk-adjusted plan payments.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for O23 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Excludes 2 — Not included here, may code separately
- gonococcal infections complicating pregnancy, childbirth and the puerperium (O98.2)
- infections with a predominantly sexual mode of transmission NOS complicating pregnancy, childbirth and the puerperium (O98.3)
- syphilis complicating pregnancy, childbirth and the puerperium (O98.1)
- tuberculosis of genitourinary system complicating pregnancy, childbirth and the puerperium (O98.0)
- venereal disease NOS complicating pregnancy, childbirth and the puerperium (O98.3)