Question 1

What is ICD-10 code O30.033?

Accepted Answer

O30.033 is the ICD-10-CM diagnosis code for Twin pregnancy, monochorionic/diamniotic, third trimester. A pregnancy with two babies sharing one placenta but each in their own amniotic sac during the third trimester (weeks 21 through delivery). O30.033 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. O30.033 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Question 2

Is O30.033 an HCC code?

Accepted Answer

No. O30.033 is a billable ICD-10-CM code but does not map to any payment HCC category under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can still be reported on Medicare Advantage encounter data submissions, but it does not contribute to the beneficiary's Risk Adjustment Factor (RAF) score and therefore does not affect the risk-adjusted capitation payment to the plan. V28 reached 100% phase-in for payment year 2026.

Question 3

Is O30.033 billable?

Accepted Answer

Yes. O30.033 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. O30.033 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Question 4

What is the V28 vs V24 difference for O30.033?

Accepted Answer

O30.033 does not map to a payment HCC under either the CMS-HCC V28 risk adjustment model or the older V24 model. V28 reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition. Because neither model rewards O30.033 with a risk adjustment factor, it contributes zero to a Medicare Advantage beneficiary's RAF score in either version. Coders should check whether provider documentation supports a more specific child code that does map to a payment HCC.

Question 5

What should coders know when reporting O30.033?

Accepted Answer

Third trimester complications and monitoring should be documented as these pregnancies require closer surveillance Use this code for weeks 21 through the end of pregnancy

O30.033

Is O30.033 an HCC code?

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Open O30.033 in the Interactive Encoder