I49.9 Cardiac arrhythmia, unspecified

Billable ICD-10-CM code, FY2026.

Applicable to

• Arrhythmia (cardiac) NOS

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)

MS-DRG index

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

Approximate ICD-9-CM (GEMs)

• 427.9 Cardiac dysrhythmia, unspecified

Code annotations containing back-references to I49.9

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 I49.9

• Action, heart › disorder
• Action, heart › irregular
• Arrhythmia (auricle)(cardiac)(juvenile)(nodal)(reflex)(supraventricular)(transitory)(ventricle)
• Disorder (of) › heart action
• Disturbance (s) › rhythm, heart
• Dysrhythmia › cardiac
• Irregular, irregularity › action, heart
• Rhythm › disorder
• Rhythm › escape
• Rhythm › heart, abnormal

Nearby codes

• I49.4 Other and unspecified premature depolarization
• I49.40 Unspecified premature depolarization
• I49.49 Other premature depolarization
• I49.5 Sick sinus syndrome
• I49.8 Other specified cardiac arrhythmias
• I49.9 Cardiac arrhythmia, unspecified (this code)