2026 ICD-10-CM Diagnosis Code O40Polyhydramnios

ICD-10-CM CodesO00-O9AO30-O48O40

ICD-10-CM O40
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

O40 is a non-billable ICD-10-CM category code for polyhydramnios, so it cannot be submitted on claims. Use a more specific code from this category instead, such as O40.1XX0, O40.1XX1, O40.1XX2, and O40.1XX3.

Code Identity

ICD-10-CM Code
O40
Billable Status
No — Non-Billable Category
Code Describes
Polyhydramnios
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
CategoryO40Polyhydramnios
This CodeO40Polyhydramnios

Specific Coding for PolyhydramniosOverview

Non-specific codes like O40 require more characters. Use one of these billable codes instead:

  • O40.1 for Polyhydramnios, first trimester

  • O40.2 for Polyhydramnios, second trimester

  • O40.3 for Polyhydramnios, third trimester

  • O40.9 for Polyhydramnios, unspecified trimester

Tabular List NotesGuidance

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

Includes

  • hydramnios

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 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

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

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Pregnancy(single) (uterine)
      • complicated by (care of) (management affected by)
        • polyhydramnios

Clinical InformationClinical

  • Polyhydramnios

    a condition of abnormally high amniotic fluid volume, such as greater than 2,000 ml in the last trimester and usually diagnosed by ultrasonographic criteria (amniotic fluid index). it is associated with maternal diabetes mellitus; multiple pregnancy; chromosomal disorders; and congenital abnormalities.

Patient EducationClinical

Health Problems in Pregnancy

A health problem in pregnancy is any disease or condition that could affect your health or the health of your fetus. Some health problems may make it more likely that you will have a high-risk pregnancy. A high-risk pregnancy is one in which you, your fetus, or both are at higher risk for health problems than in a typical pregnancy.

The full article covers:

  • What are health problems in pregnancy?
  • What raises my risk for health problems during pregnancy?
  • Can chronic health conditions cause problems in pregnancy?
  • Can health problems in pregnancy 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 O40Overview

Is O40 (Polyhydramnios) a billable code?

No. This is a category header that groups the codes for polyhydramnios, and headers cannot be submitted on claims. Claims for polyhydramnios need a more specific code from this category, such as O40.1XX0, O40.1XX1, and O40.1XX2.