ICD-9-CM diagnosis code (retired)
742.3 — Congenital hydrocephalus
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 742.3
742.3 is an ICD-9-CM diagnosis code for congenital hydrocephalus. 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 3 ICD-10-CM codes, such as Q03.0 (Malformations of aqueduct of Sylvius), Q03.1 (Atresia of foramina of Magendie and Luschka) and Q03.8 (Other congenital hydrocephalus). All of these are approximate matches, so review the record to pick the right one.
ICD-10-CM equivalents
Common questions about 742.3
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.