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ICD-10-CM 2027 diagnosis code

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

Not billable — use a more specific codeRequires 7th character

O35.06 is a header code, so it can't be reported by itself. Choose one of the 7 more specific codes beneath it and add the required 7th character.Short description: Mat care (suspected) cnsl malf/damag fts, hydrocephaly

Code last changed in FY2023 (effective October 1, 2022). Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About O35.06

O35.06 is the ICD-10-CM diagnosis code for maternal care for (suspected) central nervous system malformation or damage in fetus, hydrocephaly. It belongs to category O35 (maternal care for known or suspected fetal abnormality and damage), block O30-O48 (maternal care related to the fetus and amniotic cavity and possible delivery problems) and chapter 15 (pregnancy, childbirth and the puerperium). It is a header code, so it can't be reported by itself; one of its 7 subcodes must be used instead.

Within O35.0 (maternal care for (suspected) central nervous system malformation in fetus), O35.06 is specifically for maternal care for (suspected) central nervous system malformation or damage in fetus, hydrocephaly. Related codes cover central nervous system malformation or damage in fetus, unspecified (O35.00), central nervous system malformation or damage in fetus, agenesis of the corpus callosum (O35.01), central nervous system malformation or damage in fetus, anencephaly (O35.02), central nervous system malformation or damage in fetus, choroid plexus cysts (O35.03), central nervous system malformation or damage in fetus, encephalocele (O35.04), central nervous system malformation or damage in fetus, holoprosencephaly (O35.05), central nervous system malformation or damage in fetus, microcephaly (O35.07), central nervous system malformation or damage in fetus, spina bifida (O35.08) and 1 more.

Codes in this range require a 7th character: 0 for not applicable or unspecified, 1 for fetus 1, 2 for fetus 2, 3 for fetus 3, 4 for fetus 4, 5 for fetus 5 and 1 more. Use placeholder "X" characters to fill any empty positions before the 7th character.

It was added in FY2023, effective October 1, 2022.

7th character

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.

Coding notes

Applicable toConditions and synonyms classified to this code
  • Maternal care for fetal hydrocephalus

Notes that apply from higher levels

Instructions written at a parent level also apply to O35.06.

› From O35.0 Maternal care for (suspected) central nervous system malformation in fetus
Excludes2
  • chromosomal abnormality in fetus (O35.1-)
› From O35 Maternal care for known or suspected fetal abnormality and damage
Includes
  • the listed conditions in the fetus as a reason for hospitalization or other obstetric care to the mother, or for termination of pregnancy
Excludes1
  • encounter for suspected maternal and fetal conditions ruled out (Z03.7-)
Code also
  • any associated maternal condition

Broader instructions also apply from Chapter 15: Pregnancy, childbirth and the puerperium.

Alphabetic index entries

2 entries

Terms in the official ICD-10-CM index that lead to O35.06.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2023 (effective 10/1/2022): Added
  • No changes since FY2023.

Common questions about O35.06

Is O35.06 billable?

No. O35.06 is a header code. Report one of its more specific subcodes instead.