ICD-9-CM diagnosis code (retired)
646.23 — Unspecified renal disease in pregnancy, without mention of hypertension, antepartum condition or complication
About ICD-9-CM 646.23
646.23 is an ICD-9-CM diagnosis code for unspecified renal disease in pregnancy, without mention of hypertension, antepartum condition or complication. 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 O26.831 (Pregnancy related renal disease, first trimester), O26.832 (Pregnancy related renal disease, second trimester) and O26.833 (Pregnancy related renal disease, third trimester). All of these are approximate matches, so review the record to pick the right one.
ICD-10-CM equivalents
Common questions about 646.23
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.