Question 1

What is ICD-10 code O23.523?

Accepted Answer

O23.523 is the ICD-10-CM diagnosis code for salpingo-oophoritis in pregnancy, third trimester. An infection of the fallopian tubes and ovaries occurring during the third trimester of pregnancy. O23.523 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).

O23.523 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 third trimester dating (weeks 28+ of pregnancy) is documented.

Question 2

Is O23.523 an HCC code?

Accepted Answer

No. O23.523 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 O23.523 billable?

Accepted Answer

Yes. O23.523 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. O23.523 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 O23.523?

Accepted Answer

O23.523 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 O23.523 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 O23.523?

Accepted Answer

Confirm third trimester dating (weeks 28+ of pregnancy) is documented Monitor for potential complications that could affect labor and delivery management

O23.523

Is O23.523 an HCC code?

What This Code Means

Coding Tips

Code Hierarchy

Open O23.523 in the Interactive Encoder