Excludes1 pair
I09.2 vs I31-
I09.2 and I31 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 I09.2
chronic pericarditis not specified as rheumatic (I31.-)
I09.2
Chronic rheumatic pericarditis
Billable
- Chapter 9
- Diseases of the circulatory system
- Section
- I05-I09
Use when the record says
- Adherent pericardium, rheumatic
- Chronic rheumatic mediastinopericarditis
- Chronic rheumatic myopericarditis
Indexed under
- Concretio cordis › rheumatic
- Myopericarditis › chronic rheumatic
- Rheumatic › adherent pericardium
- Adherent › pericardium › rheumatic
- Adhesions, adhesive › cardiac › rheumatic
I31
Other diseases of pericardium
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