The AHS metros do not always match the current OMB definitions. Because the AHS is longitudinal, it is difficult to change geography each survey year without identifying individual households (which violates Census confidentiality requirements).
2015 and Later
Starting in 2015, the AHS metro area definitions match the official OMB delineations. From 2015 onwards, AHS metros match CBSA definitions of that year by the same name. See also Metropolitan Area Oversample Histories: 2015 to 2023.
1985 to 2013
For more on differences in metro area definitions from 1985 to 2013, see Metropolitan Area Histories and Geography, Public Use File: 1985-2013.
Crosswalk between 2013 and 2015
Due to changes in geographic boundaries, use caution when comparing 2015 metro estimates to prior years. Please see Summary of the Differences between the 2015 and 2013 AHS Metro Areas for more information.
Pre-1985
See Metropolitan Area Oversample Histories: 1973-2013.
Metropolitan area definitions used to define each AHS survey year sample, described in the above documents, can be mapped back to historical OMB delineation files, located on the Metropolitan and Micropolitan page.