I46.2Cardiac arrest due to underlying cardiac condition

I46.2 is the ICD-10-CM diagnosis code for cardiac arrest due to underlying cardiac condition. It belongs to category I46 (cardiac arrest), block I30-I5A (other forms of heart disease) and chapter 9 (diseases of the circulatory system). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within I46 (cardiac arrest), I46.2 is specifically for cardiac arrest due to underlying cardiac condition. Related codes cover due to other underlying condition (I46.8) and cause unspecified (I46.9).

Code first: underlying cardiac condition.

As a secondary diagnosis it is an MCC (major complication or comorbidity), which can move an inpatient stay into the highest-paying "with MCC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 296 (Cardiac Arrest, Unexplained with MCC, relative weight 1.4991), DRG 297 (Cardiac Arrest, Unexplained with CC, relative weight 0.7776), DRG 298 (Cardiac Arrest, Unexplained without CC/MCC, relative weight 0.4946), DRG 791 (Prematurity with Major Problems, relative weight 4.1075) and DRG 793 (Full Term Neonate with Major Problems, relative weight 4.2195), in MDC 05 (Diseases and Disorders of the Circulatory System) and MDC 15 (Newborns and Other Neonates with Conditions Originating in the Perinatal Period), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It is not acceptable as the principal diagnosis for an inpatient stay; it may be reported as a secondary diagnosis.

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

Before ICD-10, this condition was coded in ICD-9-CM as 427.5 (cardiac arrest).