ICD10BillableValid for clinical use

ICD-10 Code I49.9: Cardiac arrhythmia, unspecified

I49.9 is a billable ICD-10 diagnosis code used to classify Cardiac arrhythmia, unspecified 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 Diseases of the circulatory system (I00-I99).

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 Diseases of the circulatory system (I00-I99).

When is it used?

  • May be used when a clinician documents cardiac arrhythmia, unspecified 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
9Diseases of the circulatory system (I00-I99)
block
I30-I5AOther forms of heart disease
category
I49Other cardiac arrhythmias
currentI49

Official coding notes

Inclusion terms
  • Arrhythmia (cardiac) NOS

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

CardiologistGeneral Physician

Coverage-related procedures and services

CPT 78483high
CARDIAC BLOOD POOL IMAGING (PLANAR), FIRST PASS TECHNIQUE; MULTIPLE STUDIES, AT REST AND WITH STRESS (EXERCISE AND/OR PHARMACOLOGIC), WALL MOTION STUDY PLUS EJECTION FRACTION, WITH OR WITHOUT QUANTIFICATION
Source: CMS coverage guidance
CPT 78481high
CARDIAC BLOOD POOL IMAGING (PLANAR), FIRST PASS TECHNIQUE; SINGLE STUDY, AT REST OR WITH STRESS (EXERCISE AND/OR PHARMACOLOGIC), WALL MOTION STUDY PLUS EJECTION FRACTION, WITH OR WITHOUT QUANTIFICATION
Source: CMS coverage guidance
CPT 78496high
CARDIAC BLOOD POOL IMAGING, GATED EQUILIBRIUM, SINGLE STUDY, AT REST, WITH RIGHT VENTRICULAR EJECTION FRACTION BY FIRST PASS TECHNIQUE (LIST SEPARATELY IN ADDITION TO CODE FOR PRIMARY PROCEDURE)
Source: CMS coverage guidance
CPT 78494high
CARDIAC BLOOD POOL IMAGING, GATED EQUILIBRIUM, SPECT, AT REST, WALL MOTION STUDY PLUS EJECTION FRACTION, WITH OR WITHOUT QUANTITATIVE PROCESSING
Source: CMS coverage guidance
CPT 78473high
CARDIAC BLOOD POOL IMAGING, GATED EQUILIBRIUM; MULTIPLE STUDIES, WALL MOTION STUDY PLUS EJECTION FRACTION, AT REST AND STRESS (EXERCISE AND/OR PHARMACOLOGIC), WITH OR WITHOUT ADDITIONAL QUANTIFICATION
Source: CMS coverage guidance
CPT 78472high
CARDIAC BLOOD POOL IMAGING, GATED EQUILIBRIUM; PLANAR, SINGLE STUDY AT REST OR STRESS (EXERCISE AND/OR PHARMACOLOGIC), WALL MOTION STUDY PLUS EJECTION FRACTION, WITH OR WITHOUT ADDITIONAL QUANTITATIVE PROCESSING
Source: CMS coverage guidance

Coding guidelines

Compatibility

Legacy and official ICD code match exactly.
Legacy codes
I49.9

Common synonyms

Cardiac arrhythmia, unspecifiedCardiac arrhythmia

Frequently asked questions

Code details

CodeI49.9
SystemICD10
Display nameCardiac arrhythmia, unspecified
ChapterDiseases of the circulatory system (I00-I99)
BlockOther forms of heart disease

Flags

BillableYes
Valid clinical useYes

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

Index terms

Matched terms
Action, heartAction, heartArrhythmia(auricle)(cardiac)(juvenile)(nodal)(reflex)(supraventricular)(transitory)(ventricle)Disorder(of)Disturbance(s)DysrhythmiaIrregular, irregularityRhythmRhythmRhythm

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 I49.9 for Cardiac arrhythmia, unspecified | HealthAssure