ICD-9-CM diagnosis code (retired)
428.21 — Acute systolic heart failure
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 428.21
428.21 is an ICD-9-CM diagnosis code for acute systolic heart failure. 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, I50.21 (Acute systolic (congestive) heart failure). The match is approximate, so confirm it against the record.
ICD-10-CM equivalents
- I50.21Acute systolic (congestive) heart failureapproximate
Common questions about 428.21
What is the ICD-10 code for ICD-9 428.21?
- The GEMs map 428.21 to ICD-10-CM I50.21.
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.