Official State of Iowa Website

Metropolitan and Micropolitan Statistical Areas

The United States Office of Management and Budget (OMB) delineates metropolitan and micropolitan statistical areas according to published standards that are applied to Census Bureau data. The general concept of a metropolitan or micropolitan statistical area is that of a core area containing a substantial population nucleus, together with adjacent communities having a high degree of economic and social integration with that core. Current metropolitan and micropolitan statistical area delineations were announced by OMB effective July 2023.



Names of statistical areas have changed since they were first designated in 1949.

    • In 1949 standard definitions of metropolitan areas were issued under the designation "standard metropolitan area" 
    • In 1959 the term was changed to "standard metropolitan statistical area"
    • In 1983 it was changed to "metropolitan statistical area"
    • In 1990 the collective term "metropolitan area"  became effective and included metropolitan statistical areas , consolidated metropolitan statistical areas, and primary metropolitan statistical areas
    • In 2000 the collective term was changed to "core-based statistical areas" and encompassed metropolitan statistical areas and micropolitan statistical areas, which may be combined to form combined statistical areas.


Currently defined statistical areas are based on standards published in the Federal Register on July 2023. Because of historical changes in geographic definitions, users must be cautions in comparing statistical area data from different dates.

    • Mtropolitan and micropolitan statistical areas are defined in terms of whole counties
    • One or more principal cities are identified within each metropolitan and micropolitan statistical area
    • These cities are the population and employment centers and are used in titling the areas

Metropolitan statistical areas:

    • Have at least one urbanized area of 50,000 or more population and 
    • May include adjacent counties that have a minimum of 25 percent of workers commuting to the central counties of the metropolitan statistical area.

Micropolitan statistical areas:

    • Have at least one urban cluster of at least 10,000 but less than 50,000 population and
    • May include adjacent counties that have a minimum of 25 percent or workers commuting to the central counties of micropolitan statistical area.

Deliniations - Iowa Metropolitan Statistical Areas

Iowa has nine metropolitan statistical areas made up of twenty-two Iowa counties and tenn counties in other states (2023):

    • Ames, IA - Boone county (2018), Story county (2003)
    • Cedar Rapids, IA - Benton county (2003), Jones county (2003), Linn county (1950)
    • Davenport-Moline-Rock Island, IA-IL - Henry county (IL) (1963), Mercer county (IL) (2003), Rock Island county (IL) (1950), Scott county (IA) (1950)
    • Des Moines-West Des Moines, IA - Dallas county (1983), Guthrie county (2003), Jasper county (2018), Madison county (2003), Polk county (1950), Warren county (1973)
    • Dubuque, IA - Dubuque county (1960)
    • Iowa City, IA - Johnson county (1981), Washington county (2003)
    • Omaha-Council Bluffs, NE-IA - Harrison county (IA) (2003), Mills county (IA) (2003), Pottawattamie county (IA) (1950), Cass county (NE) (1993), Douglas county (NE) (1950), Sarpy county (NE) (1950), Saunders county (NE) (2003), Washington county (NE) (1983)
    • Sioux City, IA-NE-SD - Woodbury county (IA) (1950) , Dakota county (NE) (1963), Union county (SD) (2003)
    • Waterloo-Cedar Falls, IA - Black Hawk county (1960), Bremer county (2003), Grundy county (2003)

Deliniations - Iowa Micropolitan Statistical Areas

Iowa has fifteen micropolitan statistical areas made up of sixteen Iowa counties and onecounty in another state (2023):

    • Burlington, IA-IL - Henderson county (IL), Des Moines county (IA)
    • Carroll, IA - Carroll county
    • Clinton, IA - Clinton county
    • Fort Dodge, IA - Webster county
    • Fort Madison, IA- Lee county 
    • Le Mars, IA - Plymouth county
    • Marshalltown, IA - Marshall county
    • Mason City, IA - Cerro Gordo county, Worth county
    • Muscatine, IA - Muscatine county
    • Oskaloosa, IA - Mahaska county
    • Ottumwa, IA - Wapello county
    • Pella, IA - Marion county
    • Spencer, IA - Clay county
    • Spirit Lake, IA - Dickinson county
    • Storm Lake, IA - Buena Vista county

For information about statistical area standards, definitions, and concepts, see: