I51.4
Myocarditis, unspecified
Billable FY2026 2025-10-01 → 2026-09-30
This is the unspecified option. 8 more
specific codes sit alongside it. Worth
checking whether the documentation supports one of them.
Exclusions 12 never code together
I00-I99chapter
Excludes2
- certain conditions originating in the perinatal period (P04-P96)P04-P96
- certain infectious and parasitic diseases (A00-B99)A00-B99
- complications of pregnancy, childbirth and the puerperium (O00-O9A)O00-O9A
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)Q00-Q99
- endocrine, nutritional and metabolic diseases (E00-E88)E00-E88
- injury, poisoning and certain other consequences of external causes (S00-T88)S00-T88
- neoplasms (C00-D49)C00-D49
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)R00-R94
- systemic connective tissue disorders (M30-M36)M30-M36
- transient cerebral ischemic attacks and related syndromes (G45.-)G45.-
Excludes1 — never code together. The excluded condition and this one are mutually exclusive.
Excludes2 — not included here, but the patient may have both. Code both when documented.
Instructional notes 3
I51.4code
Inclusion terms
- Chronic (interstitial) myocarditis
- Myocardial fibrosis
- Myocarditis NOS
Index entries leading here 3
Alongside this code 8 same parent — I51
I51.0 Cardiac septal defect, acquired I51.1 Rupture of chordae tendineae, not elsewhere classified I51.2 Rupture of papillary muscle, not elsewhere classified I51.3 Intracardiac thrombosis, not elsewhere classified I51.5 Myocardial degeneration I51.7 Cardiomegaly I51.8 Other ill-defined heart diseases category I51.9 Heart disease, unspecified
Additional references
AHA Coding Clinic® Licence required
Official coding advice for this code. Published by the American Hospital Association. Not included in this installation.