| Place | Post Code |
|---|---|
| Bachawan, San Agustin | 5501 |
| Binongahan, San Agustin | 5501 |
| Binugusan, San Agustin | 5501 |
| Buli, San Agustin | 5501 |
| Cabolutan, San Agustin | 5501 |
| Cagbuaya, San Agustin | 5501 |
| Camantaya, San Agustin | 5501 |
| Carmen, San Agustin | 5501 |
| Cawayan, San Agustin | 5501 |
| Doña Juana, San Agustin | 5501 |
| Dubduban, San Agustin | 5501 |
| Lusong, San Agustin | 5501 |
| Mahabang Baybay, San Agustin | 5501 |
| Poblacion, San Agustin | 5501 |
| Sugod, San Agustin | 5501 |