ICD-9-CM diagnosis code (retired)
536.9 — Unspecified functional disorder of stomach
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 536.9
536.9 is an ICD-9-CM diagnosis code for unspecified functional disorder of stomach. 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 2 ICD-10-CM codes, such as K31.89 (Other diseases of stomach and duodenum) and K31.9 (Disease of stomach and duodenum, unspecified). All of these are approximate matches, so review the record to pick the right one.
ICD-10-CM equivalents
Common questions about 536.9
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.