The list is the FIPS codes of Montana counties. All the FIPS codes are starting with 30.
| County | FIPS Code |
| Beaverhead | 30001 |
| Big Horn | 30003 |
| Blaine | 30005 |
| Broadwater | 30007 |
| Carbon | 30009 |
| Carter | 30011 |
| Cascade | 30013 |
| Chouteau | 30015 |
| Custer | 30017 |
| Daniels | 30019 |
| Dawson | 30021 |
| Deer Lodge | 30023 |
| Fallon | 30025 |
| Fergus | 30027 |
| Flathead | 30029 |
| Gallatin | 30031 |
| Garfield | 30033 |
| Glacier | 30035 |
| Golden Valley | 30037 |
| Granite | 30039 |
| Hill | 30041 |
| Jefferson | 30043 |
| Judith Basin | 30045 |
| Lake | 30047 |
| Lewis and Clark | 30049 |
| Liberty | 30051 |
| Lincoln | 30053 |
| Madison | 30057 |
| McCone | 30055 |
| Meagher | 30059 |
| Mineral | 30061 |
| Missoula | 30063 |
| Musselshell | 30065 |
| Park | 30067 |
| Petroleum | 30069 |
| Phillips | 30071 |
| Pondera | 30073 |
| Powder River | 30075 |
| Powell | 30077 |
| Prairie | 30079 |
| Ravalli | 30081 |
| Richland | 30083 |
| Roosevelt | 30085 |
| Rosebud | 30087 |
| Sanders | 30089 |
| Sheridan | 30091 |
| Silver Bow | 30093 |
| Stillwater | 30095 |
| Sweet Grass | 30097 |
| Teton | 30099 |
| Toole | 30101 |
| Treasure | 30103 |
| Valley | 30105 |
| Wheatland | 30107 |
| Wibaux | 30109 |
| Yellowstone | 30111 |
| Yellowstone Nat Park | 30113 |
All codes are cited from United States Department of Agriculture [28].