ICD-10 Code I09.1 – Rheumatic diseases of endocardium, valve unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I09.1 – Rheumatic diseases of endocardium, valve unspecified
What it is
I09.1 identifies rheumatic heart disease affecting the endocardium and an unspecified valve. Use it when documentation confirms rheumatic involvement but does not name a specific valve.
Clinical signs
Clinical features vary; refer to documentation. Typical findings may include a history of rheumatic fever and evidence of valvular damage or murmurs consistent with rheumatic heart disease.
When to use this code
Use this code when the provider documents rheumatic endocardial disease with valve involvement but does not specify which valve is affected. It also fits follow-up encounters for established rheumatic valve disease when the record remains nonspecific.
If a specific valve is named, code that more precise diagnosis instead. Check documentation for whether the condition is active, historical, or part of broader rheumatic heart disease.
Do not use for
Do not use I09.1 for nonrheumatic valve disorders, infectious endocarditis, or congenital valve abnormalities. If the record identifies a specific rheumatic valve lesion, choose the more specific code.
Coding tip
Code I09.1 only when the documentation supports rheumatic origin and the affected valve is not identified.