ICD-9-CM diagnosis code (retired)
331.0 — Alzheimer's disease
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 331.0
331.0 is an ICD-9-CM diagnosis code for Alzheimer's disease. 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, G30.9 (Alzheimer's disease, unspecified). The match is approximate, so confirm it against the record.
ICD-10-CM equivalents
- G30.9Alzheimer's disease, unspecifiedapproximate
Common questions about 331.0
What is the ICD-10 code for ICD-9 331.0?
- The GEMs map 331.0 to ICD-10-CM G30.9.
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.