ICDcodes.org
FY2027

I09.2 vs I31

I09.2 and I31 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 I09.2
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 (acute) (subacute)
  • Adherent › pericardium › rheumatic
  • Adhesions, adhesive › cardiac › rheumatic (postinfective)
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