DxCodebookFY2027 · Oct 1, 2026 – Sep 30, 2027

Category · FY2027

O40 Polyhydramnios

  • Header · not billable
  • Codes take a 7th character

O40 is not billable. The category heads 28 billable codes in FY2027, grouped under 4 subdivisions. Its codes take a 7th character, so none is complete with fewer than 7 characters.

Index → code

  • Hydramnios → O40.-
  • Polyhydramnios → O40.-
  • Pregnancy (single) (uterine)complicated by (care of) (management affected by)hydramnios → O40.-

Where it sits

  1. Chapter 15 Pregnancy, childbirth and the puerperium (O00-O9A)
  2. O30-O48 Maternal care related to the fetus and amniotic cavity and possible delivery problems (O30-O48)
  3. O40 Polyhydramnios
Billable codes
28
Subdivisions
4
CC / MCC codes
0 / 0
HCC V28 codes
0
New FY2027
0
Index entries
5

Codes in O40

  1. O40.1
    Polyhydramnios, first trimester +7th: 0 1 2 3 4 5 9
    Needs 7th character
  2. O40.2
    Polyhydramnios, second trimester +7th: 0 1 2 3 4 5 9
    Needs 7th character
  3. O40.3
    Polyhydramnios, third trimester +7th: 0 1 2 3 4 5 9
    Needs 7th character
  4. O40.9
    Polyhydramnios, unspecified trimester +7th: 0 1 2 3 4 5 9
    Needs 7th character

Sources of each column. Rows marked +7th need a 7th character: pick one to build the full code; its code card has its own flags.

Instructions

At O40

Includes

  • hydramnios

Excludes1

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

Notes that also apply

Chapter 15 instructions (Notes 6, Excludes1 1, Excludes2 4, Use additional code 1): printed on the chapter 15 page.

7th characters

7th characters for O40 defined here

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.

7th characters for O40
7thMeaning (NCHS)
0not applicable or unspecified
1fetus 1
2fetus 2
3fetus 3
4fetus 4
5fetus 5
9other fetus

A code that takes a 7th character is invalid without it; the placeholder X fills a code shorter than 6 characters (Official Guidelines I.A.5). How 7th characters work.

Index entries

  • Hydramnios → O40.-
  • Polyhydramnios → O40.-
  • Pregnancy (single) (uterine)complicated by (care of) (management affected by)hydramnios → O40.-
  • Pregnancy (single) (uterine)complicated by (care of) (management affected by)polyhydramnios → O40-
  • Pregnancy (single) (uterine)complicated by (care of) (management affected by)hydropsamnii → O40.-

NCHS Alphabetic Index. Index first, then the Tabular List.

Hierarchy