ICDcodes.org
FY2027

I01.0 vs I30

I01.0 and I30 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 I01.0
acute pericarditis not specified as rheumatic (I30.-)
I01.0

Acute rheumatic pericarditis

Billable
Chapter 9
Diseases of the circulatory system
Section
I00-I02
Use when the record says
  • Any condition in I00 with pericarditis
  • Rheumatic pericarditis (acute)
Indexed under
  • Pericarditis › rheumatic (with decompensation) (with effusion)
  • Rheumatic › pericarditis (acute) (subacute)
  • Pericarditis › acute › rheumatic (with decompensation) (with effusion)
I30

Acute pericarditis

Not billable
Chapter 9
Diseases of the circulatory system
Section
I30-I5A
Use when the record says
  • acute mediastinopericarditis
  • acute myopericarditis
  • acute pericardial effusion
  • acute pleuropericarditis
  • acute pneumopericarditis

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