I00 vs I01.0
I00 (Rheumatic fever without heart involvement) compared with I01.0 (Acute rheumatic pericarditis), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. I00 carries an Excludes1 note covering I01.0: “rheumatic fever with heart involvement (I01.0 -I01.9)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Side by side
| I00Rheumatic fever without heart involvement | I01.0Acute rheumatic pericarditis | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | I00-I99 — Diseases of the Circulatory System (I00-I99) | I00-I99 — Diseases of the Circulatory System (I00-I99) |
| Definition | Rheumatic fever without heart involvement is a billable ICD-10-CM diagnosis code (I00). | Acute rheumatic pericarditis is a billable ICD-10-CM diagnosis code (I01.0). |
| Includes | arthritis, rheumatic, acute or subacute | Any condition in I00 with pericarditis Rheumatic pericarditis (acute) |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources