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ICD-10-CM 2027 diagnosis code

O33.5Maternal care for disproportion due to unusually large fetus

Not billable — use a more specific codeRequires 7th character

O33.5 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.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About O33.5

O33.5 is the ICD-10-CM diagnosis code for maternal care for disproportion due to unusually large fetus. It belongs to category O33 (maternal care for disproportion), 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 O33 (maternal care for disproportion), O33.5 is specifically for maternal care for disproportion due to unusually large fetus. Related codes cover due to deformity of maternal pelvic bones (O33.0), due to generally contracted pelvis (O33.1), due to inlet contraction of pelvis (O33.2), due to outlet contraction of pelvis (O33.3), of mixed maternal and fetal origin (O33.4), due to hydrocephalic fetus (O33.6), due to other fetal deformities (O33.7), of other origin (O33.8) 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 has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

7th character

One of the following 7th characters is to be assigned to code O33.5. 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 code O33.5 with a 7th character of 1 through 9.

Coding notes

Applicable toConditions and synonyms classified to this code
  • Maternal care for disproportion due to disproportion of fetal origin with normally formed fetus
  • Maternal care for disproportion due to fetal disproportion NOS

Notes that apply from higher levels

Instructions written at a parent level also apply to O33.5.

› From O33 Maternal care for disproportion
Includes
  • the listed conditions as a reason for observation, hospitalization or other obstetric care of the mother, or for cesarean delivery before onset of labor
Excludes1
  • disproportion with obstructed labor (O65-O66)

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

Alphabetic index entries

3 entries

Terms in the official ICD-10-CM index that lead to O33.5.

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
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about O33.5

Is O33.5 billable?

No. O33.5 is a header code. Report one of its more specific subcodes instead.