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ICD10BillableValid for clinical use

ICD-10 Code R94.31: Abnormal electrocardiogram [ECG] [EKG]

R94.31 is a billable ICD-10 diagnosis code used to classify Abnormal electrocardiogram [ECG] [EKG] 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 electrocardiogram [ecg] [ekg] 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
R94.3Abnormal results of cardiovascular function studies
currentR94.3

Official coding notes

Excludes1 (do not code together)
  • long QT syndrome (I45.81)

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

Coverage-related procedures and services

CPT 93350high
ECHOCARDIOGRAPHY, TRANSTHORACIC, REAL-TIME WITH IMAGE DOCUMENTATION (2D), INCLUDES M-MODE RECORDING, WHEN PERFORMED, DURING REST AND CARDIOVASCULAR STRESS TEST USING TREADMILL, BICYCLE EXERCISE AND/OR PHARMACOLOGICALLY INDUCED STRESS, WITH INTERPRETATION AND REPORT;
Source: CMS coverage guidance
CPT 93351high
ECHOCARDIOGRAPHY, TRANSTHORACIC, REAL-TIME WITH IMAGE DOCUMENTATION (2D), INCLUDES M-MODE RECORDING, WHEN PERFORMED, DURING REST AND CARDIOVASCULAR STRESS TEST USING TREADMILL, BICYCLE EXERCISE AND/OR PHARMACOLOGICALLY INDUCED STRESS, WITH INTERPRETATION AND REPORT; INCLUDING PERFORMANCE OF CONTINUOUS ELECTROCARDIOGRAPHIC MONITORING, WITH SUPERVISION BY A PHYSICIAN OR OTHER QUALIFIED HEALTH CARE PROFESSIONAL
Source: CMS coverage guidance
CPT 93352high
USE OF ECHOCARDIOGRAPHIC CONTRAST AGENT DURING STRESS ECHOCARDIOGRAPHY (LIST SEPARATELY IN ADDITION TO CODE FOR PRIMARY PROCEDURE)
Source: CMS coverage guidance
CPT 78454high
MYOCARDIAL PERFUSION IMAGING, PLANAR (INCLUDING QUALITATIVE OR QUANTITATIVE WALL MOTION, EJECTION FRACTION BY FIRST PASS OR GATED TECHNIQUE, ADDITIONAL QUANTIFICATION, WHEN PERFORMED); MULTIPLE STUDIES, AT REST AND/OR STRESS (EXERCISE OR PHARMACOLOGIC) AND/OR REDISTRIBUTION AND/OR REST REINJECTION
Source: CMS coverage guidance
CPT 78453high
MYOCARDIAL PERFUSION IMAGING, PLANAR (INCLUDING QUALITATIVE OR QUANTITATIVE WALL MOTION, EJECTION FRACTION BY FIRST PASS OR GATED TECHNIQUE, ADDITIONAL QUANTIFICATION, WHEN PERFORMED); SINGLE STUDY, AT REST OR STRESS (EXERCISE OR PHARMACOLOGIC)
Source: CMS coverage guidance
CPT 78452high
MYOCARDIAL PERFUSION IMAGING, TOMOGRAPHIC (SPECT) (INCLUDING ATTENUATION CORRECTION, QUALITATIVE OR QUANTITATIVE WALL MOTION, EJECTION FRACTION BY FIRST PASS OR GATED TECHNIQUE, ADDITIONAL QUANTIFICATION, WHEN PERFORMED); MULTIPLE STUDIES, AT REST AND/OR STRESS (EXERCISE OR PHARMACOLOGIC) AND/OR REDISTRIBUTION AND/OR REST REINJECTION
Source: CMS coverage guidance

Coding guidelines

Common synonyms

Abnormal electrocardiogram [ECG] [EKG]

Frequently asked questions

Code details

CodeR94.31
SystemICD10
Display nameAbnormal electrocardiogram [ECG] [EKG]
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, abnormalitiesProlonged, prolongation(of)

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 R94.31 for Abnormal electrocardiogram [ECG] [EKG] | HealthAssure