Excludes1 pair

I08- vs I38

I08 and I38 are not coded together. ICD-10-CM declares them mutually exclusive with an Excludes1 note — the two conditions are not expected to occur together, so exactly one of them is normally correct for a given encounter. The Official Guidelines carve out one exception: if the two conditions are clearly unrelated to each other, both may be reported.

The official note, declared on I08
endocarditis, valve unspecified (I38)
I08

Multiple valve diseases

Not billable
Chapter 9
Diseases of the circulatory system
Section
I05-I09
Use when the record says
  • multiple valve diseases specified as rheumatic or unspecified
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
  • Insufficiency, insufficient › valve, valvular (heart)
  • Stenosis, stenotic › heart valve

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