I05.9Rheumatic mitral valve disease, unspecified

I05.9 is the ICD-10-CM diagnosis code for rheumatic mitral valve disease, unspecified. It belongs to category I05 (rheumatic mitral valve diseases), block I05-I09 (chronic rheumatic heart diseases) and chapter 9 (diseases of the circulatory system). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within I05, choose I05.9 (Rheumatic mitral valve disease, unspecified) only when documentation doesn't support a more specific option: rheumatic mitral stenosis (I05.0), rheumatic mitral insufficiency (I05.1), rheumatic mitral stenosis with insufficiency (I05.2) and other rheumatic mitral valve diseases (I05.8).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 306 (Cardiac Congenital and Valvular Disorders with MCC, relative weight 1.546) and DRG 307 (Cardiac Congenital and Valvular Disorders without MCC, relative weight 0.9148), in MDC 05 (Diseases and Disorders of the Circulatory System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 394.9 (other and unspecified mitral valve diseases).