Question 1

What is ICD-10 code N08?

Accepted Answer

N08 is the ICD-10-CM diagnosis code for glomerular disorders in diseases classified elsewhere. Kidney filtering unit damage that occurs as a complication of another disease process classified elsewhere in the medical record. N08 sits in the ICD-10-CM chapter for diseases of the genitourinary system (n00-n99), within the section covering glomerular diseases (n00-n08).

N08 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 code the underlying disease first, then use N08 as a secondary code to indicate glomerular involvement.

Question 2

Is N08 an HCC code?

Accepted Answer

No. N08 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 N08 billable?

Accepted Answer

Yes. N08 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. N08 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 N08?

Accepted Answer

N08 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 N08 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 N08?

Accepted Answer

Always code the underlying disease first, then use N08 as a secondary code to indicate glomerular involvement Requires documentation of both the primary disease and evidence of glomerular disorder

N08

Is N08 an HCC code?

What This Code Means

Coding Tips

Excludes 1 — Do NOT code together

Code First

Code Hierarchy

Open N08 in the Interactive Encoder