What does ICD-10 code E51 mean?

ICD-10 code E51 is the standardized code used for thiamine deficiency in medical records and coding systems.

When is ICD-10 code E51 used?

Doctors, hospitals, and insurers may use ICD-10 code E51 when recording thiamine deficiency in a standardized format. This entry may also act as a broader category that points toward more specific child codes.

Does ICD-10 code E51 confirm a diagnosis?

No. A code helps standardize documentation and claims, but it should not be read as a substitute for a clinician's full assessment.

ICD10

ICD-10 Code E51: Thiamine deficiency

Name: ICD-10 Code E51: Thiamine deficiency
Creator: HealthAssure Clinical Team
Published: 2026-05-21T06:05:16.842Z

E51 is an ICD-10 diagnosis entry used to group records related to Thiamine deficiency. You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen. ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Endocrine, nutritional and metabolic diseases (E00-E89).

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Endocrine, nutritional and metabolic diseases (E00-E89).

When is it used?

May be used when a clinician documents thiamine deficiency in a patient's medical record.
May appear in hospital records, claims, referrals, and clinical documentation.
This code may act more like a grouping or parent code, so a more specific child code may be used in final documentation when available.

What it does not mean

A code alone does not explain severity, treatment plan, or outcome.
A medical code should not be treated as a substitute for a doctor's diagnosis or advice.
This entry may represent a broader category rather than the most specific billable code.

Code hierarchy

chapter

4Endocrine, nutritional and metabolic diseases (E00-E89)

block

E50-E64Other nutritional deficiencies

currentE50-E64

Official coding notes

Excludes1 (do not code together)

sequelae of thiamine deficiency (E64.8)

Where you may see this code

You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen.

Related specialists

EndocrinologistGeneral Physician

Sibling codes

E50Vitamin A deficiency E52Niacin deficiency [pellagra]billable E53Deficiency of other B group vitamins E54Ascorbic acid deficiencybillable E55Vitamin D deficiency E56Other vitamin deficiencies E58Dietary calcium deficiencybillable E59Dietary selenium deficiencybillable E60Dietary zinc deficiencybillable E61Deficiency of other nutrient elements E63Other nutritional deficiencies E64Sequelae of malnutrition and other nutritional deficiencies

Coding guidelines

Compatibility

Legacy code aligns to an official FY 2026 category. Frontend should resolve to the official category page and surface the billable child codes.

Legacy codes

E51

Replacement codes

E51.2 — Wernicke's encephalopathyE51.8 — Other manifestations of thiamine deficiencyE51.9 — Thiamine deficiency, unspecified

Common synonyms

Thiamine deficiency

Frequently asked questions

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.