I05.9 vs I34
I05.9 and I34 can never be reported together. ICD-10-CM declares them mutually exclusive with an Excludes1 note, meaning the two conditions cannot occur in the same patient — so exactly one of them is correct for any given encounter.
The official note, declared on I34
mitral valve disease (I05.9)
I05.9
Rheumatic mitral valve disease, unspecified
BillableUnspecified
- Chapter 9
- Diseases of the circulatory system
- Section
- I05-I09
Use when the record says
- Rheumatic mitral (valve) disorder (chronic) NOS
Indexed under
- Disease, diseased › mitral
- Endocarditis › mitral (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)
- Lesion › mitral (s) (nontraumatic)
- Disease, diseased › heart › mitral
- Endocarditis › mitral › with › rheumatic fever › inactive or quiescent (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)
I34
Nonrheumatic mitral valve disorders
Not billable
- Chapter 9
- Diseases of the circulatory system
- Section
- I30-I5A
Excludes1 is not always absolute: where two conditions covered by the note are genuinely unrelated, CMS guidance permits reporting both. Document the reasoning rather than assuming it. More on Excludes1 vs Excludes2 · FY2027