I09.1 vs I38
I09.1 and I38 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 I09.1
endocarditis, valve unspecified (I38)
I09.1
Rheumatic diseases of endocardium, valve unspecified
BillableUnspecified
- Chapter 9
- Diseases of the circulatory system
- Section
- I05-I09
Use when the record says
- Rheumatic endocarditis (chronic)
- Rheumatic valvulitis (chronic)
Indexed under
- Endocarditis › rheumatic (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)
- Endocarditis › with rheumatic fever › inactive or quiescent (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)
- Fever › rheumatic › inactive or quiescent with › endocarditis (inanition) (of unknown origin) (persistent) (with chills) (with rigor)
I38
Endocarditis, valve unspecified
BillableUnspecified
- Chapter 9
- Diseases of the circulatory system
- Section
- I30-I5A
Use when the record says
- endocarditis (chronic) NOS
- valvular incompetence NOS
- valvular insufficiency NOS
- valvular regurgitation NOS
- valvular stenosis NOS
- valvulitis (chronic) NOS
Indexed under
- Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)
- Disease, diseased › valve, valvular
- Endocarditis › arteriosclerotic (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)
- Insufficiency, insufficient › valve, valvular
- Stenosis, stenotic › heart valve (cicatricial)
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