O30.121
BillableTriplet pregnancy with two or more monoamniotic fetuses, first trimester
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is O30.121 an HCC code?
No. O30.121 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
O30.121 is the ICD-10-CM diagnosis code for triplet pregnancy with two or more monoamniotic fetuses, first trimester. A pregnancy with three fetuses where two or more share the same amniotic sac during the first three months of pregnancy. This is a high-risk pregnancy type requiring close monitoring. O30.121 sits in the ICD-10-CM chapter for pregnancy, childbirth and the puerperium (o00-o9a), within the section covering maternal care related to the fetus and amniotic cavity and possible delivery problems (o30-o48).
O30.121 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.
Always verify the trimester is documented as first trimester (weeks 0-13) before assigning this code.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for O30.121 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Always verify the trimester is documented as first trimester (weeks 0-13) before assigning this code
- •Confirm through ultrasound documentation that monoamniotic status (shared amniotic sac) is present for at least two of the three fetuses