ICD-9-CM diagnosis code (retired)
421.1 — Acute and subacute infective endocarditis in diseases classified elsewhere
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 421.1
421.1 is an ICD-9-CM diagnosis code for acute and subacute infective endocarditis in diseases classified elsewhere. 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, I39 (Endocarditis and heart valve disorders in diseases classified elsewhere). The match is approximate, so confirm it against the record.
ICD-10-CM equivalents
- I39Endocarditis and heart valve disorders in diseases classified elsewhereapproximate
Common questions about 421.1
What is the ICD-10 code for ICD-9 421.1?
- The GEMs map 421.1 to ICD-10-CM I39.
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.