Question 1

What is ICD-10 code R82.991?

Accepted Answer

R82.991 is the ICD-10-CM diagnosis code for hypocitraturia. Lower than normal levels of citrate in the urine, which can increase the risk of kidney stone formation. R82.991 sits in the ICD-10-CM chapter for symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (r00-r99), within the section covering abnormal findings on examination of urine, without diagnosis (r80-r82).

R82.991 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.

Hypocitraturia is a metabolic risk factor for nephrolithiasis; review for concurrent stone disease codes.

Question 2

Is R82.991 an HCC code?

Accepted Answer

No. R82.991 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 R82.991 billable?

Accepted Answer

Yes. R82.991 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. R82.991 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 R82.991?

Accepted Answer

R82.991 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 R82.991 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 R82.991?

Accepted Answer

Hypocitraturia is a metabolic risk factor for nephrolithiasis; review for concurrent stone disease codes Document quantitative lab values when available to support medical necessity

R82.991

Is R82.991 an HCC code?

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