ICD-10-CM 2027
ICD-10 code for cardiac dysrhythmia
From the official ICD-10-CM alphabetic index entry “Dysrhythmia › cardiac”. Page updated September 29, 2026.
About coding cardiac dysrhythmia
The ICD-10-CM code for cardiac dysrhythmia is I49.9 (Cardiac arrhythmia, unspecified). The official index lists 6 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 cardiac dysrhythmia codes (official index)
- newborn
- bradycardia P29.12 — Neonatal bradycardia
- occurring before birth P03.819 — Newborn affected by abnormality in fetal (intrauterine) heart rate or rhythm, unspecified as to time of onset
- before onset of labor P03.810 — Newborn affected by abnormality in fetal (intrauterine) heart rate or rhythm before the onset of labor
- during labor P03.811 — Newborn affected by abnormality in fetal (intrauterine) heart rate or rhythm during labor
- tachycardia P29.11 — Neonatal tachycardia
- postoperative I97.89 — Other postprocedural complications and disorders of the circulatory system, not elsewhere classified
Common questions about cardiac dysrhythmia ICD-10 codes
What is the ICD-10 code for cardiac dysrhythmia?
- I49.9 — Cardiac arrhythmia, unspecified. More specific codes apply when the documentation supports them: P29.12, P03.819, P03.810, P03.811 and others below.
What is the ICD-10 code for postoperative cardiac dysrhythmia?
- I97.89 — Other postprocedural complications and disorders of the circulatory system, 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.