O09.521
BillableSupervision of elderly multigravida, first trimester
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is O09.521 an HCC code?
No. O09.521 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
O09.521 is the ICD-10-CM diagnosis code for supervision of elderly multigravida, first trimester. Medical supervision during the first three months of pregnancy for a woman over 35 years old who has been pregnant before. O09.521 sits in the ICD-10-CM chapter for pregnancy, childbirth and the puerperium (o00-o9a), within the section covering supervision of high risk pregnancy (o09).
O09.521 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.
Confirm the patient has had at least one previous pregnancy to use the multigravida code.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for O09.521 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Confirm the patient has had at least one previous pregnancy to use the multigravida code
- •The fifth character '1' indicates first trimester; document trimester clearly in the record