ICD-9-CM diagnosis code (retired)
656.23 — Isoimmunization from other and unspecified blood-group incompatibility, antepartum condition or complication
About ICD-9-CM 656.23
656.23 is an ICD-9-CM diagnosis code for isoimmunization from other and unspecified blood-group incompatibility, 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 6 ICD-10-CM codes, such as O36.1110 (Maternal care for Anti-A sensitization, first trimester, not applicable or unspecified), O36.1120 (Maternal care for Anti-A sensitization, second trimester, not applicable or unspecified) and O36.1130 (Maternal care for Anti-A sensitization, third trimester, not applicable or unspecified). All of these are approximate matches, so review the record to pick the right one.
ICD-10-CM equivalents
- O36.1110Maternal care for Anti-A sensitization, first trimester, not applicable or unspecifiedapproximate
- O36.1120Maternal care for Anti-A sensitization, second trimester, not applicable or unspecifiedapproximate
- O36.1130Maternal care for Anti-A sensitization, third trimester, not applicable or unspecifiedapproximate
- O36.1910Maternal care for other isoimmunization, first trimester, not applicable or unspecifiedapproximate
- O36.1920Maternal care for other isoimmunization, second trimester, not applicable or unspecifiedapproximate
- O36.1930Maternal care for other isoimmunization, third trimester, not applicable or unspecifiedapproximate
Common questions about 656.23
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.