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ICD-10-CM 2027 diagnosis code

I49.89Other specified cardiac arrhythmias not elsewhere classified

✓ Billable / specificNew for 2027

I49.89 is a valid, billable ICD-10-CM code for other specified cardiac arrhythmias not elsewhere classified. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Looking up by condition? See ICD-10 code for Nodal rhythm, ICD-10 code for Heart flutter, ICD-10 code for Bradyarrhythmia.

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

About I49.89

I49.89 is the ICD-10-CM diagnosis code for other specified cardiac arrhythmias not elsewhere classified. It belongs to category I49 (other cardiac arrhythmias), block I30-I5A (other forms of heart disease) and chapter 9 (diseases of the circulatory system). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within I49.8 (other specified cardiac arrhythmias), I49.89 is specifically for other specified cardiac arrhythmias not elsewhere classified. Related codes cover Brugada syndrome (I49.81) and ventricular bigeminy (I49.82).

Code first cardiac arrhythmia complicating: abortion or ectopic or molar pregnancy (O00-O07, O08.8) and obstetric surgery and procedures (O75.4).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 308 (Cardiac Arrhythmia and Conduction Disorders with MCC, relative weight 1.1806), DRG 309 (Cardiac Arrhythmia and Conduction Disorders with CC, relative weight 0.7316) and DRG 310 (Cardiac Arrhythmia and Conduction Disorders without CC/MCC, relative weight 0.568), in MDC 05 (Diseases and Disorders of the Circulatory System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It was added in FY2027, effective October 1, 2026.

Coding notes

Applicable toConditions and synonyms classified to this code
  • Coronary sinus rhythm disorder
  • Ectopic rhythm disorder
  • Nodal rhythm disorder

Notes that apply from higher levels

Instructions written at a parent level also apply to I49.89.

› From I49 Other cardiac arrhythmias
Excludes2
  • bradycardia NOS (R00.1)
  • neonatal dysrhythmia (P29.1-)
  • sinoatrial bradycardia (R00.1)
  • sinus bradycardia (R00.1)
  • vagal bradycardia (R00.1)
Code first
  • cardiac arrhythmia complicating:
  • abortion or ectopic or molar pregnancy (O00-O07, O08.8)
  • obstetric surgery and procedures (O75.4)

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

Alphabetic index entries

15 entries

Terms in the official ICD-10-CM index that lead to I49.89.

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

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
  • FY2027 (effective 10/1/2026): Added

Common questions about I49.89

Is I49.89 billable?

Yes. I49.89 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can I49.89 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict I49.89 as a principal diagnosis.

Is I49.89 a CC or MCC?

No. I49.89 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does I49.89 group to?

I49.89 is used in the MS-DRG v44.0 logic for MS-DRG 308 (Cardiac Arrhythmia and Conduction Disorders with MCC), MS-DRG 309 (Cardiac Arrhythmia and Conduction Disorders with CC) and MS-DRG 310 (Cardiac Arrhythmia and Conduction Disorders without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

Did I49.89 change for 2027?

Yes. For FY2027 (effective October 1, 2026) it was added to the code set.