I49.01 Ventricular fibrillation

Billable ICD-10-CM code, FY2026. Acts as a Major Complication or Comorbidity (MCC) as a secondary diagnosis.

Applies from I49 Other cardiac arrhythmias

Excludes2 (not included here)

• 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)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 213 — Cardio-Respiratory Failure and Shock
• CMS-HCC V22: HCC 84 — Cardio-Respiratory Failure and Shock
• ESRD V24: HCC 84

MS-DRG index

Defines the logic of DRG(s) 308-310 in MDC 05.

Approximate ICD-9-CM (GEMs)

• 427.41 Ventricular fibrillation

Code annotations containing back-references to I49.01

Back-references to I49

• Code Also: M35.81 Multisystem inflammatory syndrome ("cardiac arrhythmia (I47-I49.-)")
• Type 2 Excludes: R00 Abnormalities of heart beat ("specified arrhythmias (I47-I49)")

Diagnosis Index entries for I49.01

• Fibrillation › ventricular

Nearby codes

• I49 Other cardiac arrhythmias
• I49.0 Ventricular fibrillation and flutter
• I49.01 Ventricular fibrillation (this code)
• I49.02 Ventricular flutter
• I49.1 Atrial premature depolarization
• I49.2 Junctional premature depolarization
• I49.3 Ventricular premature depolarization
• I49.4 Other and unspecified premature depolarization