| O41.121 | Chorioamnionitis, first trimester | NON-BILLABLE CODE |
| O41.1210 | Chorioamnionitis, first trimester, not applicable or unspecified | BILLABLE CODE |
| O41.1211 | Chorioamnionitis, first trimester, fetus 1 | BILLABLE CODE |
| O41.1212 | Chorioamnionitis, first trimester, fetus 2 | BILLABLE CODE |
| O41.1213 | Chorioamnionitis, first trimester, fetus 3 | BILLABLE CODE |
| O41.1214 | Chorioamnionitis, first trimester, fetus 4 | BILLABLE CODE |
| O41.1215 | Chorioamnionitis, first trimester, fetus 5 | BILLABLE CODE |
| O41.1219 | Chorioamnionitis, first trimester, other fetus | BILLABLE CODE |
| O41.122 | Chorioamnionitis, second trimester | NON-BILLABLE CODE |
| O41.1220 | Chorioamnionitis, second trimester, not applicable or unspecified | BILLABLE CODE |
| O41.1221 | Chorioamnionitis, second trimester, fetus 1 | BILLABLE CODE |
| O41.1222 | Chorioamnionitis, second trimester, fetus 2 | BILLABLE CODE |
| O41.1223 | Chorioamnionitis, second trimester, fetus 3 | BILLABLE CODE |
| O41.1224 | Chorioamnionitis, second trimester, fetus 4 | BILLABLE CODE |
| O41.1225 | Chorioamnionitis, second trimester, fetus 5 | BILLABLE CODE |
| O41.1229 | Chorioamnionitis, second trimester, other fetus | BILLABLE CODE |
| O41.123 | Chorioamnionitis, third trimester | NON-BILLABLE CODE |
| O41.1230 | Chorioamnionitis, third trimester, not applicable or unspecified | BILLABLE CODE |
| O41.1231 | Chorioamnionitis, third trimester, fetus 1 | BILLABLE CODE |
| O41.1232 | Chorioamnionitis, third trimester, fetus 2 | BILLABLE CODE |
| O41.1233 | Chorioamnionitis, third trimester, fetus 3 | BILLABLE CODE |
| O41.1234 | Chorioamnionitis, third trimester, fetus 4 | BILLABLE CODE |
| O41.1235 | Chorioamnionitis, third trimester, fetus 5 | BILLABLE CODE |
| O41.1239 | Chorioamnionitis, third trimester, other fetus | BILLABLE CODE |
| O41.129 | Chorioamnionitis, unspecified trimester | NON-BILLABLE CODE |
| O41.1290 | Chorioamnionitis, unspecified trimester, not applicable or unspecified | BILLABLE CODE |
| O41.1291 | Chorioamnionitis, unspecified trimester, fetus 1 | BILLABLE CODE |
| O41.1292 | Chorioamnionitis, unspecified trimester, fetus 2 | BILLABLE CODE |
| O41.1293 | Chorioamnionitis, unspecified trimester, fetus 3 | BILLABLE CODE |
| O41.1294 | Chorioamnionitis, unspecified trimester, fetus 4 | BILLABLE CODE |
| O41.1295 | Chorioamnionitis, unspecified trimester, fetus 5 | BILLABLE CODE |
| O41.1299 | Chorioamnionitis, unspecified trimester, other fetus | BILLABLE CODE |
