ICD-10-CM > O00-O9A > O30-O48 > O40 > O40.9 O40.9 Polyhydramnios, unspecified trimester Non-Billable/Non-Specific Codes O40.9XX0..., not applicable or unspecifiedO40.9XX1..., fetus 1O40.9XX2..., fetus 2O40.9XX3..., fetus 3O40.9XX4..., fetus 4O40.9XX5..., fetus 5O40.9XX9..., other fetus