I46Cardiac arrest

I46 is the ICD-10-CM diagnosis code for cardiac arrest. It belongs to block I30-I5A (other forms of heart disease) and chapter 9 (diseases of the circulatory system). It is a header code, so it can't be reported by itself; one of its 3 subcodes must be used instead.

To report this condition, pick the subcode that matches the documentation: I46.2 (due to underlying cardiac condition), I46.8 (due to other underlying condition) and I46.9 (cause unspecified).

The conditions in its Excludes2 note aren't part of I46, but may be coded alongside it if the patient has both: cardiogenic shock (R57.0).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.