Skip to content
Dx

ICD-10-CM 2027

ICD-10 code for Hydramnios

O40

Polyhydramnios

Header — needs a more specific code

From the official ICD-10-CM alphabetic index entry “Hydramnios”. Page updated September 29, 2026.

About coding Hydramnios

The ICD-10-CM code for Hydramnios is O40 (Polyhydramnios).

To report this condition, pick the subcode that matches the documentation: O40.1 (first trimester), O40.2 (second trimester), O40.3 (third trimester) and O40.9 (unspecified trimester).

Don't report O40 together with the conditions in its Excludes1 note: encounter for suspected maternal and fetal conditions ruled out (Z03.7-).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Don't confuse with (Excludes1 for O40)

  • encounter for suspected maternal and fetal conditions ruled out (Z03.7-)

Common questions about Hydramnios ICD-10 codes

What is the ICD-10 code for Hydramnios?

O40 — Polyhydramnios (a header code; report a more specific subcode).

Is O40 billable?

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