Post Offices List in Union County, New Mexico:
| Amistad Post Office | 21 Amistad Rd, Amistad, NM 88410 |
| Clayton Post Office | 1 Walnut St, Clayton, NM 88415 |
| Des Moines Post Office | 720 Broadway Ave, Des Moines, NM 88418 |
| Folsom Post Office | 53 Grand Ave, Folsom, NM 88419 |
| Grenville Post Office | 16 5th Ave, Grenville, NM 88424 |
| Sedan Post Office | 508 Callis Rd, Sedan, NM 88436 |