Question 1

What is ICD-10 code E52?

Accepted Answer

E52 is the ICD-10-CM diagnosis code for niacin deficiency [pellagra]. Pellagra is a disease caused by niacin (vitamin B3) deficiency, characterized by skin problems, digestive issues, mental changes, and nerve damage. E52 sits in the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89), within the section covering other nutritional deficiencies (e50-e64).

E52 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.

The classic presentation is '4 Ds': dermatitis, diarrhea, dementia, and death; document which manifestations are present.

Question 2

Is E52 an HCC code?

Accepted Answer

No. E52 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 E52 billable?

Accepted Answer

Yes. E52 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. E52 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 E52?

Accepted Answer

E52 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 E52 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 E52?

Accepted Answer

The classic presentation is '4 Ds': dermatitis, diarrhea, dementia, and death; document which manifestations are present Often associated with alcoholism or corn-based diets; consider coding the underlying cause

E52

Is E52 an HCC code?

What This Code Means

Coding Tips

Excludes 1 — Do NOT code together

Code Hierarchy

Open E52 in the Interactive Encoder