Excludes1 pair
I00 vs I01.9
I00 and I01.9 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.
I00
Rheumatic fever without heart involvement
Billable
- Chapter 9
- Diseases of the circulatory system
- Section
- I00-I02
Use when the record says
- arthritis, rheumatic, acute or subacute
Indexed under
- Fever › rheumatic (active) (acute) (chronic) (subacute)
- Pneumonia › rheumatic
- Rheumatic › pneumonia
- Erythema, erythematous › marginatum › in acute rheumatic fever (due to)
- Pneumonia › in › rheumatic fever
I01.9
Acute rheumatic heart disease, unspecified
BillableUnspecified
- Chapter 9
- Diseases of the circulatory system
- Section
- I00-I02
Use when the record says
- Any condition in I00 with unspecified type of heart involvement
- Rheumatic carditis, acute
- Rheumatic heart disease, active or acute
Indexed under
- Bouillaud's disease or syndrome (rheumatic heart disease)
- Disease, diseased › Bouillaud's (rheumatic heart disease)
- Syndrome › Bouillaud's
- Disease, diseased › heart › rheumatic › active or acute
- Disease, diseased › heart › with › rheumatic fever › active
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