2027 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 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

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
Short Description
Maternal care for known or suspected fetal abnlt 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

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to O35: its own notes plus those printed at Chapter 15. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

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

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

On O35 itself
  • encounter for suspected maternal and fetal conditions ruled out (Z03.7-)
From Chapter 15 (O00-O9A) Pregnancy, childbirth and the puerperium applies to 2,481 codes
  • supervision of normal pregnancy (Z34.-)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 15 (O00-O9A) Pregnancy, childbirth and the puerperium applies to 2,481 codes
  • mental and behavioral disorders associated with the puerperium (F53.-)
  • obstetrical tetanus (A34)
  • postpartum necrosis of pituitary gland (E23.0)
  • puerperal osteomalacia (M83.0)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From Chapter 15 (O00-O9A) Pregnancy, childbirth and the puerperium applies to 2,481 codes
  • code, if applicable, from category Z3A, Weeks of gestation, to identify the specific week of the pregnancy, if known.

Code Also

A second code may be needed to fully describe the condition; the note gives no sequencing direction.

  • any associated maternal condition

Notes

General instructions on how these codes are used.

From Chapter 15 (O00-O9A) Pregnancy, childbirth and the puerperium applies to 2,481 codes
  • CODES FROM THIS CHAPTER ARE FOR USE ONLY ON MATERNAL RECORDS, NEVER ON NEWBORN RECORDS
  • Codes from this chapter are for use for conditions related to or aggravated by the pregnancy, childbirth, or by the puerperium (maternal causes or obstetric causes)
  • Trimesters are counted from the first day of the last menstrual period. They are defined as follows:
  • 1st trimester- less than 14 weeks 0 days
  • 2nd trimester- 14 weeks 0 days to less than 28 weeks 0 days
  • 3rd trimester- 28 weeks 0 days until delivery

7th Character

Every code in the category takes a 7th character from the listed values, with the placeholder X filling any empty positions before it.

  • 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, Multiple gestation, must also be assigned when assigning a code from category O35 that has a 7th character of 1 through 9.
Values for category O35 Fetus Identification
  • 0not applicable or unspecified
  • 1fetus 1
  • 2fetus 2
  • 3fetus 3
  • 4fetus 4
  • 5fetus 5
  • 9other fetus

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name O35, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming O35: they are not reported together with it, unless the two conditions are unrelated.

  • Z03.7 Encounter for suspected maternal and fetal conditions ruled out
    known or suspected fetal anomalies affecting management of mother, not ruled out (O26.-, O35.-, O36.-, O40.-, O41.-)

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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About O35Overview

What is the ICD-10 code for maternal care for known or suspected fetal abnormality and damage?

O35 is the ICD-10-CM category for maternal care for known or suspected fetal abnormality and damage, but it is a non-billable header: claims need a more specific code from this category, listed on this page.

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.

Can O35 be reported with a code from Z03.7?

Not as a rule. The Excludes1 note on O35 lists "encounter for suspected maternal and fetal conditions ruled out (Z03.7-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).