ICD-10-CM 2027
ICD-10 code for disorder action
From the official ICD-10-CM alphabetic index entry “Action, heart › disorder”. Page updated September 29, 2026.
About coding disorder action
The ICD-10-CM code for disorder action is I49.9 (Cardiac arrhythmia, unspecified).
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.
Common questions about disorder action ICD-10 codes
What is the ICD-10 code for disorder action?
- I49.9 — Cardiac arrhythmia, unspecified.
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.