| County | FIPS |
|---|---|
| Ada County | 16001 |
| Adams County | 16003 |
| Bannock County | 16005 |
| Bear Lake County | 16007 |
| Benewah County | 16009 |
| Bingham County | 16011 |
| Blaine County | 16013 |
| Boise County | 16015 |
| Bonner County | 16017 |
| Bonneville County | 16019 |
| Boundary County | 16021 |
| Butte County | 16023 |
| Camas County | 16025 |
| Canyon County | 16027 |
| Caribou County | 16029 |
| Cassia County | 16031 |
| Clark County | 16033 |
| Clearwater County | 16035 |
| Custer County | 16037 |
| Elmore County | 16039 |
| Franklin County | 16041 |
| Fremont County | 16043 |
| Gem County | 16045 |
| Gooding County | 16047 |
| Idaho County | 16049 |
| Jefferson County | 16051 |
| Jerome County | 16053 |
| Kootenai County | 16055 |
| Latah County | 16057 |
| Lemhi County | 16059 |
| Lewis County | 16061 |
| Lincoln County | 16063 |
| Madison County | 16065 |
| Minidoka County | 16067 |
| Nez Perce County | 16069 |
| Oneida County | 16071 |
| Owyhee County | 16073 |
| Payette County | 16075 |
| Power County | 16077 |
| Shoshone County | 16079 |
| Teton County | 16081 |
| Twin Falls County | 16083 |
| Valley County | 16085 |
| Washington County | 16087 |