Encephalopathy ICD-10-CM Coding: Types, Guidelines, and Documentation Tips 

Overview of Encephalopathy 

Encephalopathy refers to a broad category of brain dysfunction that can result from a variety of underlying conditions, including metabolic disturbances, infections, toxins, hypoxia, or organ failure. 

It is commonly seen in inpatient settings and often represents a clinically significant condition that impacts severity of illness, resource utilization, and patient outcomes. 

Types of Encephalopathy and ICD-10-CM Codes 

Accurate coding depends on identifying the underlying cause and type of encephalopathy documented. 

Common ICD-10-CM codes include: 

• G93.40 – Encephalopathy, unspecified
• G93.41 – Metabolic encephalopathy
• G93.49 – Other encephalopathy 

Additional related codes based on etiology: 

• K76.82 – Hepatic encephalopathy 
• F05 – Delirium due to known physiological condition
• Toxic encephalopathy → code from T36–T65 with 5th/6th character for intent 

Code assignment should reflect the most specific type of encephalopathy documented. 

Documentation Requirements for Accurate Coding 

Provider documentation should clearly identify: 

The type of encephalopathy (metabolic, toxic, hepatic, anoxic, etc.)
The underlying cause or condition 
Clinical indicators supporting the diagnosis 

Avoid use of unspecified encephalopathy (G93.40) when further clarification is supported by the clinical picture. 

Coding and CDI Tips for Encephalopathy 

Differentiate encephalopathy from delirium or altered mental status when possible 

Query when documentation uses nonspecific terms such as: 

• “AMS” 
• “confusion” 
• “encephalopathic changes” 

Link encephalopathy to underlying causes (e.g., sepsis, renal failure, liver disease, medications) 

Recognize that metabolic encephalopathy (G93.41) is a MCC and impacts severity capture 

Review labs and clinical indicators such as: 

• Elevated ammonia 
• Electrolyte imbalance 
• Hypoxia 
• Infection markers 

Clinical Indicators Supporting Encephalopathy 

Common clinical indicators may include: 

• Altered level of consciousness
• Confusion or disorientation
• Lethargy or agitation
• Abnormal EEG findings
• Metabolic abnormalities (e.g., sodium imbalance, uremia, hyperammonemia) 

Treatment may include: 

• Correction of underlying cause
• IV fluids
• Electrolyte replacement
• Lactulose (for hepatic causes)
• Antibiotics (if infectious etiology is present) 

Query Opportunities for Encephalopathy 

A query may be appropriate when: 

• Documentation reflects altered mental status without a defined diagnosis 
• Clinical indicators support a metabolic or toxic etiology 
• There is a known underlying condition (e.g., sepsis, renal failure) with neurologic changes 

FY 2026 Coding Considerations 

ICD-10-CM classification for encephalopathy remains stable in FY 2026, with continued emphasis on: 

• Coding the specific type and underlying cause 
• Avoiding unspecified diagnoses when documentation supports specificity
• Capturing conditions that impact CC/MCC status and SOI/ROM 

Lori Amende, RHIA, CCS 

Education and Quality Manager at UASI

Works Cited 

Centers for Medicare & Medicaid Services. (2025). ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026. 

American Hospital Association. (2024). Encephalopathy coding guidance. AHA Coding Clinic for ICD-10-CM/PCS. 

National Library of Medicine. (2024). Encephalopathy. MedlinePlus Medical Encyclopedia. Available at: https://medlineplus.gov/ency/article/001415.htm