The list is the FIPS codes of Maine counties. All the FIPS codes are starting with 23.
| County | FIPS Code |
| Androscoggin | 23001 |
| Aroostook | 23003 |
| Cumberland | 23005 |
| Franklin | 23007 |
| Hancock | 23009 |
| Kennebec | 23011 |
| Knox | 23013 |
| Lincoln | 23015 |
| Oxford | 23017 |
| Penobscot | 23019 |
| Piscataquis | 23021 |
| Sagadahoc | 23023 |
| Somerset | 23025 |
| Waldo | 23027 |
| Washington | 23029 |
| York | 23031 |
All codes are cited from United States Department of Agriculture [28].