Post Offices List in Columbia City, Maryland:
| Columbia Post Office | 6801 Oak Hall Ln, Columbia, MD 21045 |
| American Cities Post Office | 10500 Little Patuxent Pkwy Ste 190, Columbia, MD 21044 |
| Columbia Post Office | 6801 Oak Hall Ln, Columbia, MD 21045 |
| American Cities Post Office | 10500 Little Patuxent Pkwy Ste 190, Columbia, MD 21044 |