E51.2 Wernicke's encephalopathy

The ICD-10-CM code for Wernicke's encephalopathy is E51.2 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

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

Section

E50-E64: Other nutritional deficiencies (E50-E64)

Category E51

7 codes (5 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to E51.2:

• Polioencephalopathy, superior hemorrhagic
• Wernicke's › disease or syndrome
• Polioencephalomyelitis (acute) (anterior) › with beriberi
• Polioencephalitis (acute) (bulbar) › Wernicke's
• Hemorrhage, hemorrhagic (concealed) › polioencephalitis, superior
• Wernicke's › encephalopathy
• Encephalopathy (acute) › Wernicke's
• Polioencephalitis (acute) (bulbar) › superior hemorrhagic (acute) (Wernicke's)

U.S. Hospital Utilization

• An estimated 26,230 U.S. inpatient stays in 2023 included E51.2 among the documented diagnoses.
• 3,630 stays listed it as the principal diagnosis.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

Official Coding Guidelines

Diabetes mellitus (TOC entry)

a. Diabetes mellitus ................................................................................................................... 39

Obesity (TOC entry)

b. Obesity .................................................................................................................................. 42

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool
• AHRQ — HCUP National Inpatient Sample, Frequencies by Diagnosis Code (2016–2023)