2026 ICD-10-CM Diagnosis Code O35Maternal care for known or suspected fetal abnormality and damage

ICD-10-CM Codes›O00-O9A›O30-O48›O35

ICD-10-CM O35
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

O35 is a non-billable ICD-10-CM category code for maternal care for known or suspected fetal abnormality and damage, so it cannot be submitted on claims. Use a more specific code from this category instead, such as O35.00X0, O35.00X1, O35.00X2, and O35.00X3.

Code Identity

ICD-10-CM Code
O35
Billable Status
No — Non-Billable Category
Code Describes
Maternal care for known or suspected fetal abnormality and damage
Chapter
O30-O48
Maternal care related to the fetus and amniotic cavity and possible delivery problems

Code Classification

ChapterO00-O9APregnancy, childbirth and the puerperium
SectionO30-O48Maternal care related to the fetus and amniotic cavity and possible delivery problems
CategoryO35Maternal care for known or suspected fetal abnormality and damage
This CodeO35Maternal care for known or suspected fetal abnormality and damage

Specific Coding for Maternal care for known or suspected fetal abnlt and damageOverview

Non-specific codes like O35 require more characters. Use one of these billable codes instead:

  • O35.0 for Maternal care for (suspected) central nervous system malformation in fetus

  • O35.00 for Maternal care for (suspected) central nervous system malformation or damage in fetus, unspecified

  • O35.01 for Maternal care for (suspected) central nervous system malformation or damage in fetus, agenesis of the corpus callosum

  • O35.02 for Maternal care for (suspected) central nervous system malformation or damage in fetus, anencephaly

  • O35.03 for Maternal care for (suspected) central nervous system malformation or damage in fetus, choroid plexus cysts

  • O35.04 for Maternal care for (suspected) central nervous system malformation or damage in fetus, encephalocele

  • O35.05 for Maternal care for (suspected) central nervous system malformation or damage in fetus, holoprosencephaly

  • O35.06 for Maternal care for (suspected) central nervous system malformation or damage in fetus, hydrocephaly

  • O35.07 for Maternal care for (suspected) central nervous system malformation or damage in fetus, microcephaly

  • O35.08 for Maternal care for (suspected) central nervous system malformation or damage in fetus, spina bifida

  • O35.09 for Maternal care for (suspected) other central nervous system malformation or damage in fetus

  • O35.1 for Maternal care for (suspected) chromosomal abnormality in fetus

  • O35.10 for Maternal care for (suspected) chromosomal abnormality in fetus, unspecified

  • O35.11 for Maternal care for (suspected) chromosomal abnormality in fetus, Trisomy 13

  • O35.12 for Maternal care for (suspected) chromosomal abnormality in fetus, Trisomy 18

  • O35.13 for Maternal care for (suspected) chromosomal abnormality in fetus, Trisomy 21

  • O35.14 for Maternal care for (suspected) chromosomal abnormality in fetus, Turner Syndrome

  • O35.15 for Maternal care for (suspected) chromosomal abnormality in fetus, sex chromosome abnormality

  • O35.19 for Maternal care for (suspected) chromosomal abnormality in fetus, other chromosomal abnormality

  • O35.2 for Maternal care for (suspected) hereditary disease in fetus

  • O35.3 for Maternal care for (suspected) damage to fetus from viral disease in mother

  • O35.4 for Maternal care for (suspected) damage to fetus from alcohol

  • O35.5 for Maternal care for (suspected) damage to fetus by drugs

  • O35.6 for Maternal care for (suspected) damage to fetus by radiation

  • O35.7 for Maternal care for (suspected) damage to fetus by other medical procedures

  • O35.8 for Maternal care for other (suspected) fetal abnormality and damage

  • O35.9 for Maternal care for (suspected) fetal abnormality and damage, unspecified

  • O35.A for Maternal care for other (suspected) fetal abnormality and damage, fetal facial anomalies

  • O35.B for Maternal care for other (suspected) fetal abnormality and damage, fetal cardiac anomalies

  • O35.C for Maternal care for other (suspected) fetal abnormality and damage, fetal pulmonary anomalies

  • O35.D for Maternal care for other (suspected) fetal abnormality and damage, fetal gastrointestinal anomalies

  • O35.E for Maternal care for other (suspected) fetal abnormality and damage, fetal genitourinary anomalies

  • O35.F for Maternal care for other (suspected) fetal abnormality and damage, fetal musculoskeletal anomalies of trunk

  • O35.G for Maternal care for other (suspected) fetal abnormality and damage, fetal upper extremities anomalies

  • O35.H for Maternal care for other (suspected) fetal abnormality and damage, fetal lower extremities anomalies

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Includes

  • the listed conditions in the fetus as a reason for hospitalization or other obstetric care to the mother, or for termination of pregnancy

Code Also

  • any associated maternal condition

Type 1 Excludes

  • encounter for suspected maternal and fetal conditions ruled out Z03.7

7th Character Note

  • One of the following 7th characters is to be assigned to each code under category O35. 7th character 0 is for single gestations and multiple gestations where the fetus is unspecified. 7th characters 1 through 9 are for cases of multiple gestations to identify the fetus for which the code applies. The appropriate code from category O30

7th Character

  • 0 - not applicable or unspecified
  • 1 - fetus 1
  • 2 - fetus 2
  • 3 - fetus 3
  • 4 - fetus 4
  • 5 - fetus 5
  • 9 - other fetus

Patient EducationClinical

Birth Defects

A birth defect is a problem that happens while a baby is developing in the mother's body. Most birth defects happen during the first 3 months of pregnancy. One out of every 33 babies in the United States is born with a birth defect.

The full article covers:

  • What are birth defects?
  • What causes birth defects?
  • Who is at risk of having a baby with birth defects?
  • How are birth defects diagnosed?
  • What are the treatments for birth defects?
  • Can birth defects be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About O35Overview

Is O35 a billable code?

No. This is a category header that groups the codes for maternal care for known or suspected fetal abnormality and damage, and headers cannot be submitted on claims. Claims for maternal care for known or suspected fetal abnormality and damage need a more specific code from this category, such as O35.00X0, O35.00X1, and O35.00X2.