FIPS Code | State | County name | 2003 urban influence code | Description | 2000 population |
|---|
| 12001 | FL | Alachua County | 2 | Small-in a metro area with fewer than 1 million residents | 217,955 |
| 12003 | FL | Baker County | 1 | Large-in a metro area with at least 1 million residents or more | 22,259 |
| 12005 | FL | Bay County | 2 | Small-in a metro area with fewer than 1 million residents | 148,217 |
| 12007 | FL | Bradford County | 6 | Noncore adjacent to a small metro with town of at least 2,500 residents | 26,088 |
| 12009 | FL | Brevard County | 2 | Small-in a metro area with fewer than 1 million residents | 476,230 |
| 12011 | FL | Broward County | 1 | Large-in a metro area with at least 1 million residents or more | 1,623,018 |
| 12013 | FL | Calhoun County | 7 | Noncore adjacent to a small metro and does not contain a town of at least 2,500 residents | 13,017 |
| 12015 | FL | Charlotte County | 2 | Small-in a metro area with fewer than 1 million residents | 141,627 |
| 12017 | FL | Citrus County | 5 | Micropolitan adjacent to a small metro area | 118,085 |
| 12019 | FL | Clay County | 1 | Large-in a metro area with at least 1 million residents or more | 140,814 |
| 12021 | FL | Collier County | 2 | Small-in a metro area with fewer than 1 million residents | 251,377 |
| 12023 | FL | Columbia County | 5 | Micropolitan adjacent to a small metro area | 56,513 |
| 12027 | FL | DeSoto County | 5 | Micropolitan adjacent to a small metro area | 32,209 |
| 12029 | FL | Dixie County | 7 | Noncore adjacent to a small metro and does not contain a town of at least 2,500 residents | 13,827 |
| 12031 | FL | Duval County | 1 | Large-in a metro area with at least 1 million residents or more | 778,879 |
| 12033 | FL | Escambia County | 2 | Small-in a metro area with fewer than 1 million residents | 294,410 |
| 12035 | FL | Flagler County | 5 | Micropolitan adjacent to a small metro area | 49,832 |
| 12037 | FL | Franklin County | 7 | Noncore adjacent to a small metro and does not contain a town of at least 2,500 residents | 11,057 |
| 12039 | FL | Gadsden County | 2 | Small-in a metro area with fewer than 1 million residents | 45,087 |
| 12041 | FL | Gilchrist County | 2 | Small-in a metro area with fewer than 1 million residents | 14,437 |
| 12043 | FL | Glades County | 4 | Noncore adjacent to a large metro area | 10,576 |
| 12045 | FL | Gulf County | 6 | Noncore adjacent to a small metro with town of at least 2,500 residents | 13,332 |
| 12047 | FL | Hamilton County | 7 | Noncore adjacent to a small metro and does not contain a town of at least 2,500 residents | 13,327 |
| 12049 | FL | Hardee County | 5 | Micropolitan adjacent to a small metro area | 26,938 |
| 12051 | FL | Hendry County | 5 | Micropolitan adjacent to a small metro area | 36,210 |
| 12053 | FL | Hernando County | 1 | Large-in a metro area with at least 1 million residents or more | 130,802 |
| 12055 | FL | Highlands County | 5 | Micropolitan adjacent to a small metro area | 87,366 |
| 12057 | FL | Hillsborough County | 1 | Large-in a metro area with at least 1 million residents or more | 998,948 |
| 12059 | FL | Holmes County | 6 | Noncore adjacent to a small metro with town of at least 2,500 residents | 18,564 |
| 12061 | FL | Indian River County | 2 | Small-in a metro area with fewer than 1 million residents | 112,947 |
| 12063 | FL | Jackson County | 6 | Noncore adjacent to a small metro with town of at least 2,500 residents | 46,755 |
| 12065 | FL | Jefferson County | 2 | Small-in a metro area with fewer than 1 million residents | 12,902 |
| 12067 | FL | Lafayette County | 7 | Noncore adjacent to a small metro and does not contain a town of at least 2,500 residents | 7,022 |
| 12069 | FL | Lake County | 1 | Large-in a metro area with at least 1 million residents or more | 210,528 |
| 12071 | FL | Lee County | 2 | Small-in a metro area with fewer than 1 million residents | 440,888 |
| 12073 | FL | Leon County | 2 | Small-in a metro area with fewer than 1 million residents | 239,452 |
| 12075 | FL | Levy County | 7 | Noncore adjacent to a small metro and does not contain a town of at least 2,500 residents | 34,450 |
| 12077 | FL | Liberty County | 7 | Noncore adjacent to a small metro and does not contain a town of at least 2,500 residents | 7,021 |
| 12079 | FL | Madison County | 6 | Noncore adjacent to a small metro with town of at least 2,500 residents | 18,733 |
| 12081 | FL | Manatee County | 2 | Small-in a metro area with fewer than 1 million residents | 264,002 |
| 12083 | FL | Marion County | 2 | Small-in a metro area with fewer than 1 million residents | 258,916 |
| 12085 | FL | Martin County | 2 | Small-in a metro area with fewer than 1 million residents | 126,731 |
| 12086 | FL | Miami-Dade County | 1 | Large-in a metro area with at least 1 million residents or more | 2,253,362 |
| 12087 | FL | Monroe County | 3 | Micropolitan adjacent to a large metro area | 79,589 |
| 12089 | FL | Nassau County | 1 | Large-in a metro area with at least 1 million residents or more | 57,663 |
| 12091 | FL | Okaloosa County | 2 | Small-in a metro area with fewer than 1 million residents | 170,498 |
| 12093 | FL | Okeechobee County | 5 | Micropolitan adjacent to a small metro area | 35,910 |
| 12095 | FL | Orange County | 1 | Large-in a metro area with at least 1 million residents or more | 896,344 |
| 12097 | FL | Osceola County | 1 | Large-in a metro area with at least 1 million residents or more | 172,493 |
| 12099 | FL | Palm Beach County | 1 | Large-in a metro area with at least 1 million residents or more | 1,131,184 |
| 12101 | FL | Pasco County | 1 | Large-in a metro area with at least 1 million residents or more | 344,765 |
| 12103 | FL | Pinellas County | 1 | Large-in a metro area with at least 1 million residents or more | 921,482 |
| 12105 | FL | Polk County | 2 | Small-in a metro area with fewer than 1 million residents | 483,924 |
| 12107 | FL | Putnam County | 3 | Micropolitan adjacent to a large metro area | 70,423 |
| 12109 | FL | St. Johns County | 1 | Large-in a metro area with at least 1 million residents or more | 123,135 |
| 12111 | FL | St. Lucie County | 2 | Small-in a metro area with fewer than 1 million residents | 192,695 |
| 12113 | FL | Santa Rosa County | 2 | Small-in a metro area with fewer than 1 million residents | 117,743 |
| 12115 | FL | Sarasota County | 2 | Small-in a metro area with fewer than 1 million residents | 325,957 |
| 12117 | FL | Seminole County | 1 | Large-in a metro area with at least 1 million residents or more | 365,196 |
| 12119 | FL | Sumter County | 3 | Micropolitan adjacent to a large metro area | 53,345 |
| 12121 | FL | Suwannee County | 6 | Noncore adjacent to a small metro with town of at least 2,500 residents | 34,844 |
| 12123 | FL | Taylor County | 6 | Noncore adjacent to a small metro with town of at least 2,500 residents | 19,256 |
| 12125 | FL | Union County | 7 | Noncore adjacent to a small metro and does not contain a town of at least 2,500 residents | 13,442 |
| 12127 | FL | Volusia County | 2 | Small-in a metro area with fewer than 1 million residents | 443,343 |
| 12129 | FL | Wakulla County | 2 | Small-in a metro area with fewer than 1 million residents | 22,863 |
| 12131 | FL | Walton County | 6 | Noncore adjacent to a small metro with town of at least 2,500 residents | 40,601 |
| 12133 | FL | Washington County | 6 | Noncore adjacent to a small metro with town of at least 2,500 residents | 20,973 |