ICD-10 Code I49.0 – Ventricular fibrillation and flutter (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I49.0 – Ventricular fibrillation and flutter
What it is
I49.0 identifies ventricular fibrillation and ventricular flutter, dangerous rhythm disturbances that start in the lower chambers of the heart. These rhythms prevent effective pumping and are treated as medical emergencies.
Clinical signs
Patients may have sudden collapse, loss of consciousness, or no detectable pulse. Clinical features vary; refer to documentation, ECG findings, and the provider’s final rhythm diagnosis.
When to use this code
Use I49.0 when the provider documents ventricular fibrillation, ventricular flutter, or both as the diagnosed rhythm disturbance. It may be appropriate in emergency, inpatient, or post-resuscitation records when the arrhythmia is confirmed. Code the documented condition, not a nonspecific cardiac arrest alone.
Do not use for
Do not use this code for atrial fibrillation, atrial flutter, or other supraventricular arrhythmias. If the record only says “cardiac arrest” or “ventricular tachycardia,” check documentation before assigning I49.0.
Coding tip
Assign I49.0 only when the provider clearly names ventricular fibrillation or flutter in the final diagnosis.