O28.1
BillableAbnormal biochemical finding on antenatal screening of mother
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is O28.1 an HCC code?
No. O28.1 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.
This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).
What This Code Means
O28.1 is the ICD-10-CM diagnosis code for abnormal biochemical finding on antenatal screening of mother. An abnormal chemical or protein level found during routine screening tests performed on a pregnant woman. O28.1 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).
O28.1 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.
Specify the type of biochemical abnormality if documented (e.g., low PAPP-A, elevated hCG).
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for O28.1 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Specify the type of biochemical abnormality if documented (e.g., low PAPP-A, elevated hCG)
- •Distinguish between screening results and confirmed diagnoses; this code is for screening findings only