I40 — Acute myocarditis
Is I40 billable?
No — I40 is a non-billable header code. I40 groups more specific codes and cannot be submitted on a claim. A valid ICD-10-CM code must be reported at the highest level of specificity available in its branch. Select one of the 4 billable codes beneath I40.
Billable codes under this header
I40 at a glance
| Code | I40 |
|---|---|
| Description | Acute myocarditis |
| Billable | No — header code |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Excludes1 — never code together
The conditions below can never be reported together with I40 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- acute rheumatic myocarditis (I01.2)
Includes
Conditions classified to I40.
- subacute myocarditis
Excludes2 — not included here — inherited from Chapter 9
The conditions below are not part of I40, but a patient may have both at the same time. When documentation supports it, I40 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.-)
What codes fall under I40? (4)
How long has I40 existed?
I40 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.
Which codes are confused with I40?
ICD-10-CM declares these codes mutually exclusive with I40 — exactly one of each pair can be correct for a given encounter.