In February 2005, the South Dakota Labor Market Information Center began publishing several labor market measures using new Metropolitan and Micropolitan definitions. Historical data was also revised to reflect the new area definitions. The geographic changes followed guidelines implemented by the Office of Management and Budget.

The Office of Management and Budget (OMB) maintains and updates statistical area classifications, a task it has performed every decade since the 1950 Census. As a result of the 2000 Census, the OMB finalized and released new statistical area definitions on February 18, 2004. The area definitions are based on population and commuting within communities.

In South Dakota, there are two basic area types: metropolitan areas and micropolitan areas. The official definition of a Metropolitan Statistical Area (MSA) is that it must have at least one urbanized area of 50,000 or more population, plus adjacent territory with a high degree of social and economic integration with the core as measured by commuting ties.

For the past decade, South Dakota had two MSAs, Rapid City and Sioux Falls. Under the new definition, these two MSAs still exist, but their composition changed. In addition, one county in South Dakota (Union) became part of the Sioux City MSA. Below is a table listing the counties in the previously defined MSA and how they are now defined.

In addition to the new metropolitan statistical areas, the OMB also defined a new set of areas called micropolitan statistical areas. The official definition of a micropolitan area is at least one urban cluster of at least 10,000 but less than 50,000 population, plus adjacent territory with a high degree of social and economic integration with the core as measured by commuting ties.

According to these definitions for micropolitan areas, South Dakota has nine areas. The table below lists the micropolitan statistical area names and the counties in that area.