ICD-10 Code I46.9 – Cardiac arrest, cause unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I46.9 – Cardiac arrest, cause unspecified
What it is
I46.9 identifies a cardiac arrest when the cause is not documented or not yet known. Use it for the event itself, not for the underlying disease that triggered it.
Clinical signs
Clinical features vary; refer to documentation. Cardiac arrest is typically described as sudden loss of pulse, unresponsiveness, and absence of normal breathing or effective circulation.
When to use this code
Use I46.9 when the record states cardiac arrest but does not specify a cause. It is also appropriate when the cause remains undetermined after evaluation. If the chart identifies an underlying condition, code that condition as directed.
Do not use for
Do not use this code for syncope, respiratory arrest, or cardiac arrest with a documented cause. Check documentation if the note describes resuscitation only without confirming arrest.
Coding tip
Query for the cause whenever possible, because unspecified arrest may not capture the full clinical picture.