ICD10BillableValid for clinical use

ICD-10 Code R94.01: Abnormal electroencephalogram [EEG]

R94.01 is a billable ICD-10 diagnosis code used to classify Abnormal electroencephalogram [EEG] in medical records and claims. You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records. ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99).

Reviewed by HealthAssure Clinical TeamUpdated 26 May 2026

What is this code?

ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99).

When is it used?

  • May be used when a clinician documents abnormal electroencephalogram [eeg] in a patient's medical record.
  • May appear in hospital records, claims, referrals, and clinical documentation.
  • This code can be used as a clinically usable diagnosis entry in standardized coding workflows.

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.

Code hierarchy

chapter
18Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)
block
R90-R94Abnormal findings on diagnostic imaging and in function studies, without diagnosis
category
R94Abnormal results of function studies
category
R94.0Abnormal results of function studies of central nervous system
currentR94.0

Where you may see this code

You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.

Related specialists

General Physician

Coding guidelines

Common synonyms

Abnormal electroencephalogram [EEG]

Frequently asked questions

Code details

CodeR94.01
SystemICD10
Display nameAbnormal electroencephalogram [EEG]
ChapterSymptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)
BlockAbnormal findings on diagnostic imaging and in function studies, without diagnosis

Flags

BillableYes
Valid clinical useYes

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

Index terms

Matched terms
Abnormal, abnormality, abnormalities

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.

ICD-10 Code R94.01 for Abnormal electroencephalogram [EEG] | HealthAssure