Guidance on Uses of Statistical Area Definitions

Guidance on Uses of Statistical Area Definitions

  • August 20th, 2019

All Agencies Should Use the Most Recent Definitions. All agencies that conduct statistical activities to collect and publish data for Metropolitan, Micropolitan, and Combined Statistical Areas, and New England City and Town Areas should use the most recent definitions of these areas established by OMB.

The Definitions Are for Statistical Purposes Only. OMB establishes and maintains the definitions of Metropolitan and Micropolitan Statistical Areas, Combined Statistical Areas, and New England City and Town Areas solely for statistical purposes. This classification is intended to provide nationally consistent definitions for collecting, tabulating, and publishing federal statistics for a set of geographic areas.

Inquiries. Inquiries concerning the Metropolitan and Micropolitan Statistical Area Standards and the statistical uses of their definitions should be directed to Suzann Evinger (202-395-3093) at OMB. Inquiries about uses of the statistical area definitions in program administration or regulation should be directed to the appropriate agency.

Metropolitan Is Not the Same as Urban. The Metropolitan and Micropolitan Statistical Area Standards do not equate to an urban-rural classification; many counties included in Metropolitan and Micropolitan Statistical Areas, and many other counties, contain both urban and rural territory and populations.

Nonstatistical Program Uses of the Statistical Area Definitions. In periodically reviewing and revising the definitions of these areas, OMB does not take into account or attempt to anticipate any nonstatistical uses that may be made of the definitions, nor will OMB modify the definitions to meet the requirements of any nonstatistical program. Thus, OMB cautions that Metropolitan Statistical Area and Micropolitan Statistical Area definitions should not be used to develop and implement federal, state, and local nonstatistical programs and policies without full consideration of the effects of using these definitions for such purposes.

Metro and Micro Areas May Not be Suitable for Program Funding Formulas. These areas are not intended to serve as a general-purpose geographic framework for nonstatistical activities, and they may or may not be suitable for use in program funding formulas. OMB recognizes that some legislation specifies the use of Metropolitan Statistical Areas for program purposes, including the allocation of federal funds, and will continue to work with the Congress to clarify the foundations of these definitions and the resultant, often unintended consequences of their use for nonstatistical purposes.

It Is the Sponsoring Agency’s Responsibility to Know What Is Appropriate. In cases where there is no statutory requirement and an agency elects to use the Metropolitan, Micropolitan, or Combined Statistical Area definitions in nonstatistical programs, it is the sponsoring agency’s responsibility to ensure that the definitions are appropriate for such use. When an agency is publishing for comment a proposed regulation that would use the definitions for a nonstatistical purpose, the agency should seek public comment on the proposed use.

An agency using the statistical definitions in a nonstatistical program may modify the definitions, but only for the purposes of that program. In such cases, any modifications should be clearly identified as deviations from the OMB statistical area definitions in order to avoid confusion with OMB’s official definitions of Metropolitan, Micropolitan, and Combined Statistical Areas.

In addition, in light of recent changes to the statistical area definitions, OMB urges federal agencies that use the statistical areas for allocating program funds to provide information to the public on their plans and schedules for using the new definitions.

New Terminology—Be Careful! The 2000 standards changed the terminology used for classifying the areas. Under the 1980 and 1990 standards there were two types of areas:
(1) Metropolitan Statistical Areas and
(2) Consolidated Metropolitan Statistical Areas that consisted of Primary Metropolitan Statistical Areas.
The terms “Consolidated Metropolitan Statistical Area” and “Primary Metropolitan Statistical Area” are now obsolete.

“Metropolitan Division” Replaces “Primary Metropolitan Statsitical Area.” Under the 2000 standards, “Metropolitan Statistical Area” and “Micropolitan Statistical Area” are the terms used for the basic set of county-based areas defined under this classification. In addition, the term “Metropolitan Division” is used to refer to a county or group of counties within a Metropolitan Statistical Area that has a population core of at least 2.5 million. A Metropolitan Division is most generally comparable in concept, and equivalent to, the now obsolete Primary Metropolitan Statistical Area.

While a Metropolitan Division is a subdivision of a larger Metropolitan Statistical Area, it often functions as a distinct social, economic, and cultural area with the larger region. Metropolitan Divisions retain their separate statistical identities. Federal agencies will continue to provide detailed data for each Metropolitan Division, just as they did in the past for the Primary Metropolitan Statistical Areas.

If federal agencies have been using the Primary Metropolitan Statistical Area for program administrative and fund allocation purposes, they should now consider using the Metropolitan Division definitions, the comparable geographic units of the classification based on the 2000 standards. Research and analyses that previously used data for Primary Metropolitan Statistical Areas should now use data for Metropolitan Divisions. Data users and analysts interested in demographic and economic patterns, trends, and processes within large Metropolitan Statistical Areas should consider data for specific Metropolitan Divisions when conducting analyses.

Be Careful When Comparing to 1990 Data. Users making comparisons with areas defined under the 1990 standards should note that when the 2000 standards were applied, the result, in some cases, was to create several areas from an existing Metropolitan Statistical Area. The resulting reconfigured areas may also qualify under the 2000 standards to form a complementary Combined Statistical Area, while retaining their separate designations as Metropolitan or Micropolitan Statistical Areas. In these situations, the Combined Statistical Area may be the approximate geographic equivalent of the previous Metropolitan Statistical Area, and thus may be the more appropriate geographic unit for analytic and program purposes.

Sometimes the Combined Statistical Area Will Be the Only Geography Reported for Data Tabulations. Federal agencies will be making economic and demographic data available for Metropolitan and Micropolitan Statistical Areas, Metropolitan Divisions, New England City and Town Areas, and Combined Statistical Areas. Because of sample sizes and associated data quality and confidentiality issues, there may be instances where agencies will produce data only at the level of Combined Statistical Areas.

Electronic Links to Useful Sites. The OMB bulletin from which this report was taken is available electronically from the OMB website at

The 2000 Standards for Defining Metropolitan and Micropolitan Statistical Areas are available at

Other background documents are available at

Historical definitions of Metropolitan Statistical Areas are available from the Census Bureau’s web site at: