2027 ICD-10-CM Diagnosis Code I48Atrial fibrillation and flutter

ICD-10-CM Codes›I00–I99›I30-I5A›I48

ICD-10-CM I48
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

I48 is a non-billable ICD-10-CM category code for atrial fibrillation and flutter, so it cannot be submitted on claims. Use a more specific code from this category instead, such as I48.0, I48.11, I48.19, and I48.20.

This medical diagnosis code is frequently used in Cardiology medical specialties to designate conditions such atrial fibrillation and flutter.

Code Identity

ICD-10-CM Code
I48
Billable Status
No — Non-Billable Category
Code Describes
Atrial fibrillation and flutter
Short Description
Atrial fibrillation and flutter
Same as the full description in the CMS dataset.
Chapter
I30-I5A
Other forms of heart disease

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI30-I5AOther forms of heart disease
CategoryI48Atrial fibrillation and flutter
This CodeI48Atrial fibrillation and flutter

Specific Coding for Atrial fibrillation and flutterOverview

Non-specific codes like I48 require more characters. Use one of these billable codes instead:

  • Use I48.0 for Paroxysmal atrial fibrillation

  • I48.1 for Persistent atrial fibrillation

  • Use I48.11 for Longstanding persistent atrial fibrillation

  • Use I48.19 for Other persistent atrial fibrillation

  • I48.2 for Chronic atrial fibrillation

  • Use I48.20 for Chronic atrial fibrillation, unspecified

  • Use I48.21 for Permanent atrial fibrillation

  • Use I48.3 for Typical atrial flutter

  • Use I48.4 for Atypical atrial flutter

  • I48.9 for Unspecified atrial fibrillation and atrial flutter

  • Use I48.91 for Unspecified atrial fibrillation

  • Use I48.92 for Unspecified atrial flutter

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to I48: its own notes plus those printed at Chapter 9. A note printed at a category, block or chapter applies to every code under it.

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 9 (I00-I99) Diseases of the circulatory system applies to 1,433 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
  • systemic connective tissue disorders (M30-M36)
  • transient cerebral ischemic attacks and related syndromes (G45.-)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name I48, its category, or a range that includes it.

Excludes2 1

These codes carry an Excludes2 note naming I48: its condition is not part of those codes, and both may be reported when the patient has both.

  • R00 Abnormalities of heart beat
    specified arrhythmias (I47-I49) names I47-I49, which includes this code

Code Also 1

These codes say I48 may also be needed to fully describe the condition. The note gives no sequencing direction.

  • M35.81 Multisystem inflammatory syndrome
    cardiac arrhythmia (I47-I49.-) names I47-I49, which includes this code

Patient EducationClinical

Arrhythmia

An arrhythmia is a problem with the rate or rhythm of your heartbeat. Your heart beats too quickly, too slowly, or with an irregular pattern. Changes in the electrical signals that control your heartbeat cause arrhythmias.

The full article covers:

  • What is an arrhythmia?
  • What causes an arrhythmia?
  • What are the symptoms of an arrhythmia?
  • How is an arrhythmia diagnosed?
  • What are the treatments for an arrhythmia?
  • Can arrhythmias be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About I48Overview

What is the ICD-10 code for atrial fibrillation and flutter?

I48 is the ICD-10-CM category for atrial fibrillation and flutter, but it is a non-billable header: claims need a more specific code from this category, listed on this page.

Is I48 (Atrial fibrillation and flutter) a billable code?

No. This is a category header that groups the codes for atrial fibrillation and flutter, and headers cannot be submitted on claims. Claims for atrial fibrillation and flutter need a more specific code from this category, such as I48.0, I48.11, and I48.19.