ICD-9-CM diagnosis code (retired)
420.91 — Acute idiopathic pericarditis
ICD-9-CM was replaced by ICD-10 on October 1, 2015. These are the ICD-10-CM equivalents from the CMS General Equivalence Mappings.
About ICD-9-CM 420.91
420.91 is an ICD-9-CM diagnosis code for acute idiopathic pericarditis. ICD-9-CM was retired for U.S. claims on October 1, 2015, when ICD-10-CM took over.
The CMS General Equivalence Mappings translate it to one ICD-10-CM code, I30.0 (Acute nonspecific idiopathic pericarditis). The match is exact.
ICD-10-CM equivalents
- I30.0Acute nonspecific idiopathic pericarditisexact match
Common questions about 420.91
What is the ICD-10 code for ICD-9 420.91?
- The GEMs map 420.91 to ICD-10-CM I30.0.
GEMs are a translation aid, not a substitute for coding from the record. The 2027 ICD-10 code set has changed since the last GEMs release in 2018. Page updated September 29, 2026.