ICD-10 Code I34.1 – Nonrheumatic mitral (valve) prolapse (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I34.1 – Nonrheumatic mitral (valve) prolapse
What it is
I34.1 identifies mitral valve prolapse that is not due to rheumatic disease. The mitral valve leaflets bulge back into the left atrium during systole.
Clinical signs
Clinical features vary; refer to documentation. Commonly documented findings include a midsystolic click, possible late systolic murmur, and echocardiographic evidence of leaflet prolapse.
When to use this code
Use I34.1 when the provider documents nonrheumatic mitral valve prolapse, with or without symptoms. It is appropriate when echocardiography or the assessment clearly names mitral valve prolapse. If the record only says “mitral valve disorder,” check documentation before coding.
Do not use for
Do not use this code for rheumatic mitral valve disease or for other mitral valve disorders without prolapse. If prolapse is not documented, do not assume it from a murmur alone.
Coding tip
Code the condition only when the provider explicitly links the diagnosis to nonrheumatic mitral valve prolapse.