Alaska's Unique Geography in FIPS Codes

Alaska is the most geographically unusual state in the US for data purposes. Rather than counties, Alaska has boroughs, census areas (unorganized areas that exist only for statistical purposes), and one consolidated home-rule city (Juneau). All of these are county-equivalents for federal statistical purposes, meaning they each get their own 3-digit FIPS county code appended to Alaska's 2-digit state code (02). Alaska's FIPS page lists all of Alaska's county-equivalents.

As of the 2020 Census, Alaska has 19 organized boroughs (similar to counties) and 11 census areas — the remainder of the state divided into statistical units by the Census Bureau since there's no local government to define boundaries. Census areas don't correspond to any governmental jurisdiction; they exist purely so that every part of Alaska is assigned to a county-equivalent for federal data reporting.

Alaska's geography also changes more frequently than most states. Wade Hampton Census Area was renamed Kusilvak Census Area in 2015 (FIPS code changed from 02270 to 02158). Chugach Census Area (02063) and Copper River Census Area (02066) were created from Valdez-Cordova Census Area (02261) in 2019. When working with historical Alaska data, these code changes can cause joins to break if you don't account for vintage-specific code lists.

Despite these complexities, Alaska county-equivalent FIPS codes work the same way as mainland county codes in every federal dataset. They appear in Census ACS data, BLS employment statistics, EPA environmental data, and all other standard federal products. The 5-digit codes follow the same state + county structure: 02020 is Anchorage, 02090 is Fairbanks North Star Borough. Use the search tool to look up any Alaska code, or browse via Alaska's state page.