O40 Polyhydramnios

The ICD-10-CM code for Polyhydramnios is O40 (FY2026). It is a non-billable category code — select a more specific code below for claims.

Classification

Chapter

15: Pregnancy, childbirth and the puerperium (O00-O9A)

Section

O30-O48: Maternal care related to the fetus and amniotic cavity and possible delivery problems (O30-O48)

Category O40

5 codes (4 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to O40:

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

Official Coding Guidelines

Inconclusive suspected fetal condition: assign O35/O36/O40/O41

For encounters for suspected fetal condition that are inconclusive following testing and evaluation, assign the appropriate code from category O35, O36, O40 or O41.

7th character fetus identification; assign 0 in specified cases

6) 7th character for fetus identification Where applicable, a 7th character is to be assigned for certain categories (O31, O32, O33.3 - O33.6, O35, O36, O40, O41, O60.1, O60.2, O64, and O69) to identify the fetus for which the complication code applies. Assign 7th character “0”: • For single gestations • When the documentation in the record is insufficient to determine the fetus affected and it is not possible to obtain clarification. • When it is not possible to clinically determine which fetus is affected.

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool