I34.1 vs Q87.4
I34.1 (Nonrheumatic mitral (valve) prolapse) compared with Q87.4 (Marfan syndrome), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. I34.1 carries an Excludes1 note covering Q87.4: “Marfan's syndrome (Q87.4-)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Side by side
| I34.1Nonrheumatic mitral (valve) prolapse | Q87.4Marfan syndrome | |
|---|---|---|
| Billing status | Billable | Non-billable header |
| Classification | I00-I99 — Diseases of the Circulatory System (I00-I99) | Q00-Q99 — Congenital Malformations, Deformations and Chromosomal Abnormalities (Q00-Q99) |
| Definition | Nonrheumatic mitral (valve) prolapse is a billable ICD-10-CM diagnosis code (I34.1). | Marfan syndrome is a non-billable ICD-10-CM category code (Q87.4). |
| Includes | Floppy nonrheumatic mitral valve syndrome | — |
| Use additional code | — | code(s) to identify all associated manifestations |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources