ICD-10-CM 2027
ICD-10 code for Sinoatrial node dysfunction
From the official ICD-10-CM alphabetic index entry “Dysfunction › sinoatrial node”. Page updated September 29, 2026.
About coding Sinoatrial node dysfunction
The ICD-10-CM code for Sinoatrial node dysfunction is I49.5 (Sick sinus syndrome).
Within I49 (other cardiac arrhythmias), I49.5 is specifically for sick sinus syndrome. Related codes cover 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), other specified cardiac arrhythmias (I49.8) and cardiac arrhythmia, unspecified (I49.9).
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 Sinoatrial node dysfunction ICD-10 codes
What is the ICD-10 code for Sinoatrial node dysfunction?
- I49.5 — Sick sinus syndrome.
Is I49.5 billable?
- Yes. I49.5 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can I49.5 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict I49.5 as a principal diagnosis.
Is I49.5 a CC or MCC?
- No. I49.5 is neither a CC nor an MCC under MS-DRG v44.0.