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ICD-10-CM 2027 diagnosis code

O40.3Polyhydramnios, third trimester

Not billable — use a more specific codeRequires 7th character

O40.3 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 O40.3

O40.3 is the ICD-10-CM diagnosis code for polyhydramnios, third trimester. It belongs to category O40 (polyhydramnios), 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 O40 (polyhydramnios), O40.3 is specifically for polyhydramnios, third trimester. Related codes cover first trimester (O40.1), second trimester (O40.2) and unspecified trimester (O40.9).

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 each code under category O40. 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 O40 that has a 7th character of 1 through 9.

Notes that apply from higher levels

Instructions written at a parent level also apply to O40.3.

› From O40 Polyhydramnios
Includes
  • hydramnios
Excludes1
  • encounter for suspected maternal and fetal conditions ruled out (Z03.7-)

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

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 O40.3

Is O40.3 billable?

No. O40.3 is a header code. Report one of its more specific subcodes instead.