Alphabetic Index FY2027

I46.2

Cardiac arrest due to underlying cardiac condition

FY2027Chapter 9: Diseases of the circulatory system/I30–I5A Other forms of heart disease

BillableComplete code, valid to report
Care settingsHospice: not accepted as primaryHospital MCC · if discharged alive

I46.2 (also written I462) is a billable ICD-10-CM diagnosis code for cardiac arrest due to underlying cardiac condition. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 3 codes in category I46 (Cardiac arrest). The Alphabetic Index lists it under 1 entry. Its coding notes include a Code first instruction and 11 Excludes2 entries.

Code first

If the underlying condition listed here is present and known, sequence it first.

This code
  • underlying cardiac condition

Excludes2

Not included here. Both codes may be reported if the patient has both conditions.

Inherited from I46 Cardiac arrest
  • cardiogenic shock (R57.0)
Also from chapter/block level (10 notes)
Inherited from Chapter 9 Diseases of the circulatory system
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
  • systemic connective tissue disorders (M30-M36)
  • transient cerebral ischemic attacks and related syndromes (G45.-)

Care settings

How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.

Hospice: not accepted as primary

Not accepted as the principal diagnosis on a hospice claim (bill types 081x and 082x). The Integrated OCE returns an edit for this code.
Reason: Supplementary or additional code, not allowed as principal diagnosis.

Source: CMS Integrated Outpatient Code Editor (IOCE) v27.3, effective October 1, 2026, edit 113

Hospital MCC · alive discharges only

Counts as an MCC only if the patient is discharged alive. Otherwise it is a non-CC. Counts as a major complication or comorbidity (MCC) when reported as a secondary diagnosis on an inpatient claim. It does not count when the principal diagnosis is one of the 25 codes in its exclusion list. Some MS-DRGs also ignore a CC or MCC that defines the DRG.

Source: CMS MS-DRG Definitions Manual v44, effective October 1, 2026, Appendix C (Part 2)

Alphabetic Index terms

Terms the official Alphabetic Index lists for this code. 1 entry