The Census Supplemental Survey, a predecessor of the ACS, began in 2000 with data products for geographic units with 250,000 or more persons. Geographic coverage expanded significantly in 2005, and further expansion is planned until data become available for all census geography down to the block-group level in 2010.

Geographic Coverage Prior to 2005

From 2000 through 2003, Census Supplemental Survey and the ACS provided Michigan data for:
- the state as a whole
- seven to nine congressional districts
- five metropolitan statistical areas
   (Grand Rapids-Muskegon-Holland, Lansing-East Lansing,
   Kalamazoo-Battle Creek, Detroit-Ann Arbor-Flint, and
   Saginaw-Bay City-Midland)
- seven counties
   (Genesee, Ingham, Kent, Macomb, Oakland,
    Washtenaw, and Wayne)
- the city of Detroit.

Ottawa county was added in 2004 as its estimated population edged above 250,000.

Geographic Coverage for 2005

Figures for 2005 are being provided for units of geography with more than 65,000 persons.  For Michigan, that includes:

- state total

- all congressional districts

- all metropolitan statistical areas (MSA's) and combined statistical areas (CSA's)

- the Grand Traverse micropolitan area and several single-county micropolitan areas

- 27 counties, containing 84% of Michigan's population:
    Allegan, Bay, Berrien, Calhoun, Clinton, Eaton, Genesee,
    Grand Traverse, Ingham, Jackson, Kalamazoo, Kent, Lapeer,
    Lenawee, Livingston, Macomb, Midland, Monroe, Muskegon,
    Oakland, Ottawa, Saginaw, Saint Clair, Shiawassee,
    Van Buren, Washtenaw, Wayne.

- 18 cities: 
    Ann Arbor, Dearborn, Detroit, Farmington Hills, Flint,
    Grand Rapids, Kalamazoo, Lansing, Livonia, Pontiac,
    Rochester Hills, Southfield, Sterling Heights, Taylor,
    Troy, Warren, Westland, Wyoming.

- 6 townships: 
    Canton township, Clinton township, Macomb township,
    Shelby charter township, Waterford charter township,
    West Bloomfield charter township.

Geographic Coverage after 2005

Coverage of the ACS will increase each year from 2006 through 2010:

- Areas with 65,000 or more persons:  Beginning with the release of 2006 data in 2007, figures will be released each year with respect to the total population rather than just the population in households.

- Areas with 20,000 or more persons: Beginning in 2008, three-year averages will be released each year for all units of geography with 20,000 or more people.

- Smaller units of geography: Beginning in 2010, five-year averages will be released each year for all units of census geography down to census tracts and block groups.

Additional information on geographic coverage of the ACS can be obtained from:
   http://www.census.gov/acs/www/

Updated 7/31/2006

Library of Michigan, Department of History, Arts and Libraries