| Locality | Post Code |
|---|---|
| Amelia, Saint Mary | 70340 |
| Baldwin, Saint Mary | 70514 |
| Bayou Vista, Saint Mary | 70380 |
| Berwick, Saint Mary | 70342 |
| Calumet, Saint Mary | 70392 |
| Centerville, Saint Mary | 70522 |
| Charenton, Saint Mary | 70523 |
| Cypremort Point, Saint Mary | 70538 |
| Franklin, Saint Mary | 70538 |
| Garden City, Saint Mary | 70540 |
| Glenwild, Saint Mary | 70342 |
| Idlewild, Saint Mary | 70392 |
| Jeanerette, Saint Mary | 70544 |
| Morgan City, Saint Mary | 70380, 70381 |
| Patterson, Saint Mary | 70392 |