ICD-10-CM 2027
ICD-10 code for disorder rhythm
From the official ICD-10-CM alphabetic index entry “Rhythm › disorder”. Page updated September 29, 2026.
About coding disorder rhythm
The ICD-10-CM code for disorder rhythm is I49.9 (Cardiac arrhythmia, unspecified). The official index lists 3 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on I49.9.
Within I49, choose I49.9 (Cardiac arrhythmia, unspecified) only when documentation doesn't support a more specific option: ventricular fibrillation and flutter (I49.0), atrial premature depolarization (I49.1), junctional premature depolarization (I49.2), ventricular premature depolarization (I49.3), other and unspecified premature depolarization (I49.4), sick sinus syndrome (I49.5) and other specified cardiac arrhythmias (I49.8).
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.
More specific disorder rhythm codes (official index)
Common questions about disorder rhythm ICD-10 codes
What is the ICD-10 code for disorder rhythm?
- I49.9 — Cardiac arrhythmia, unspecified. More specific codes apply when the documentation supports them: I49.89, I49.89, I49.89.
What is the ICD-10 code for coronary sinus disorder rhythm?
- I49.89 — Other specified cardiac arrhythmias not elsewhere classified.
What is the ICD-10 code for ectopic disorder rhythm?
- I49.89 — Other specified cardiac arrhythmias not elsewhere classified.
What is the ICD-10 code for nodal disorder rhythm?
- I49.89 — Other specified cardiac arrhythmias not elsewhere classified.
Is I49.9 billable?
- Yes. I49.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can I49.9 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict I49.9 as a principal diagnosis.
Is I49.9 a CC or MCC?
- No. I49.9 is neither a CC nor an MCC under MS-DRG v44.0.