I46.8 — Cardiac arrest due to other underlying condition
Is I46.8 billable?
Yes — I46.8 is billable for FY2027. I46.8 is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. I46.8 may be submitted for encounters from October 1, 2026 through September 30, 2027.
I46.8 at a glance
| Code | I46.8 |
|---|---|
| Description | Cardiac arrest due to other underlying condition |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
What Medicare edits apply to I46.8?
The Medicare Code Editor screens inpatient claims before they are grouped. These edits name I46.8 directly.
CMS will reject this code as the principal diagnosis on an inpatient claim. It describes something other than the condition chiefly responsible for the admission.
Which MS-DRGs does I46.8 group to?
I46.8 sits in MDC 05 and helps define the logic of 3 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 296Cardiac Arrest, Unexplained with MCCmedical
- 297Cardiac Arrest, Unexplained with CCmedical
- 298Cardiac Arrest, Unexplained without CC/MCCmedical
As a secondary diagnosis, I46.8 is a major complication or comorbidity (MCC), which can move a stay into a higher-paying DRG.
How is I46.8 listed in the Alphabetic Index?
These are the routes through the Alphabetic Index that lead to I46.8. They show the wording a clinician may have documented, which often differs from the Tabular description.
- Arrest, arrested › cardiac › due to › specified condition NEC
Code first
The underlying condition below must be sequenced before I46.8. I46.8 describes a manifestation and cannot be the principal or first-listed diagnosis.
- underlying condition
Excludes2 — not included here — inherited from Chapter 9
The conditions below are not part of I46.8, but a patient may have both at the same time. When documentation supports it, I46.8 and the excluded code may both be reported.
- 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.-)
Excludes2 — not included here — inherited from I46
The conditions below are not part of I46.8, but a patient may have both at the same time. When documentation supports it, I46.8 and the excluded code may both be reported.
- cardiogenic shock (R57.0)
How long has I46.8 existed?
I46.8 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.