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ICD-10-CM 2027 diagnosis code

I48.2Chronic atrial fibrillation

Not billable — use a more specific code

I48.2 is a header code, so it can't be reported by itself. Choose one of the 2 more specific codes beneath it.

Code last changed in FY2020 (effective October 1, 2019). Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About I48.2

I48.2 is the ICD-10-CM diagnosis code for chronic atrial fibrillation. It belongs to category I48 (atrial fibrillation and flutter), block I30-I5A (other forms of heart disease) and chapter 9 (diseases of the circulatory system). It is a header code, so it can't be reported by itself; one of its 2 subcodes must be used instead.

Within I48 (atrial fibrillation and flutter), I48.2 is specifically for chronic atrial fibrillation. Related codes cover paroxysmal atrial fibrillation (I48.0), persistent atrial fibrillation (I48.1), Typical atrial flutter (I48.3), atypical atrial flutter (I48.4) and unspecified atrial fibrillation and atrial flutter (I48.9).

To report this condition, pick the subcode that matches the documentation: I48.20 (unspecified) and I48.21 (fibrillation).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015, and changed in FY2020 (expanded into subcodes).

Before ICD-10, this condition was coded in ICD-9-CM as 427.31 (atrial fibrillation).

Specific codes under I48.2

Notes that apply from higher levels

Instructions written at a parent level also apply to I48.2.

Broader instructions also apply from Chapter 9: Diseases of the circulatory system.

ICD-9-CM equivalent

Converter →
  • 427.31Atrial fibrillationapproximate

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • FY2020 (effective 10/1/2019): Expanded — no longer billable

Common questions about I48.2

Is I48.2 billable?

No. I48.2 is a header code. Report one of its more specific subcodes instead.

What is the ICD-9 code for I48.2?

The CMS General Equivalence Mappings map I48.2 to ICD-9-CM 427.31.