ICD-10-CM > O00-O9A > O30-O48 > O41 > O41.1 > O41.12 > O41.129 O41.129 Chorioamnionitis, unspecified trimester Non-Billable/Non-Specific Codes O41.1290..., not applicable or unspecifiedO41.1291..., fetus 1O41.1292..., fetus 2O41.1293..., fetus 3O41.1294..., fetus 4O41.1295..., fetus 5O41.1299..., other fetus