I33.9
Acute and subacute endocarditis, unspecified
Billable FY2026 2025-10-01 → 2026-09-30
This is the unspecified option. 1 more
specific code 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 6
I33.9code
Inclusion terms
- Acute endocarditis NOS
- Acute myoendocarditis NOS
- Acute periendocarditis NOS
- Subacute endocarditis NOS
- Subacute myoendocarditis NOS
- Subacute periendocarditis NOS
Index entries leading here 1
- Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular) I38
- acute or subacute I33.9
- aortic (heart) (nonrheumatic) (valve) I35.8
- acute or subacute I33.9
- mitral (chronic) (double) (fibroid) (heart) (inactive) (valve) (with chorea) I05.9
- pulmonary (chronic) (heart) (valve) I37.8
- acute or subacute I33.9
- tricuspid (chronic) (heart) (inactive) (rheumatic) (valve) (with chorea) I07.9
- toxic I33.9
Alongside this code 1 same parent — I33
Medications 1
MED-RT files conditions by MeSH, which carves the world differently from ICD-10. These are name matches on this code's description, offered as candidates — not as an assertion that they are this code.
Additional references
AHA Coding Clinic® Licence required
Official coding advice for this code. Published by the American Hospital Association. Not included in this installation.