ICD-10-CM > O00-O9A > O30-O48 > O36 > O36.2 > O36.20 O36.20 Maternal care for hydrops fetalis, unspecified trimester Non-Billable/Non-Specific Codes O36.20X0..., not applicable or unspecifiedO36.20X1..., fetus 1O36.20X2..., fetus 2O36.20X3..., fetus 3O36.20X4..., fetus 4O36.20X5..., fetus 5O36.20X9..., other fetus