DSDR KB:

There is data for Washtenaw county. The limit on population size for aggregate data is 65,000. That means there will be annual data for Washtenaw county. The 2005 data did not include group quarters data so be cautious in making comparisons between 2000 and 2005 or 2005 and 2006.

28 counties are available for the state of Michigan. The following link provides a map of Michigan with the sampled counties colored in yellow:

http://www.census.gov/acs/www/Products/usersguide/2006/State%20PDF%20files/MIACS06.pdf

The next size cutpoint for ACS data is for geographic units that have a population of 20,000. These areas will have 3-year data available in 2008. The following link is to County Estimates data from the Census Bureau.

http://www.census.gov/popest/counties/CO-EST2007-01.html

Based on the population estimates, an additional 36 additional counties should be available in 2008.

Here's a link to the time-line for data release based on the population size of geographic units:

http://www.census.gov/acs/www/Products/usersguide/2006Release_Schedule.pdf

Washtenaw county can also be identified in the ACS microdata via PUMAs. There are two PUMAs that represent Washtenaw county. They are PUMA 03200 and PUMA 03300.