Geographical Mobility/Migration

The American Community Survey (ACS) and the Puerto Rico Community Survey (PRCS) ask respondents age 1 year and over whether they lived in the same residence 1 year ago. For people who lived in a different residence, the location of their previous residence is collected. The state-to-state migration flows are created from tabulations of the current state (including the District of Columbia and Puerto Rico) of residence crossed by state of residence 1 year ago. Tables of ACS state-to-state flows are available going back to the 2005 ACS – the first year of full implementation of the survey. People living in group quarters (e.g. adult correctional facilities, nursing facilities, college/university student housing, and military quarters) were added to the sample for the first time starting with the 2006 ACS.

The rows in each table represent the state of current residence and the columns represent the state of residence 1 year ago. The cells where the current residence and residence 1 year ago are the same are the estimated number of people who moved within the state. The 2010 table was enhanced to include estimates for the population 1 year and over for each state, nonmovers, and movers from abroad.

Currently, there are no state-to-state migration flows by characteristics available as an ACS standard product. Data users can create their own tabulations using public use microdata sample (PUMS) files.

• 2011 [XLS - 109K]  1-year ACS.
• 2010 [XLS - 105K]  1-year ACS.
• 2009 [XLS - 126K]  1-year ACS.
• 2007-2009 [XLS - 128K]  3-year ACS.
• 2005-2009 [XLS - 129K]  5-year ACS.
• 2008 [XLS - 87K]  1-year ACS.
• 2006-2008 [XLS - 90K]  3-year ACS.
• 2007 [XLS - 77K]  1-year ACS.
• 2005-2007 [XLS - 77K]  3-year ACS.
• 2006 [XLS - 77]  1-year ACS.
• 2005 [XLS - 76]  1-year ACS.

Table Notes:
Sample size and data quality measures (including coverage rates, allocation rates, and response rates) can be found on the American Community Survey website in the Methodology section.

Data are based on a sample and are subject to sampling variability. The degree of uncertainty for an estimate arising from sampling variability is represented through the use of a margin of error. The value shown here is the 90 percent margin of error. The margin of error can be interpreted roughly as providing a 90 percent probability that the interval defined by the estimate minus the margin of error and the estimate plus the margin of error (the lower and upper confidence bounds) contains the true value. In addition to sampling variability, the ACS estimates are subject to nonsampling error (for a discussion of nonsampling variability, see Accuracy of the Data). The effect of nonsampling error is not represented in these tables.

Region-to-Region Migration Flows
Estimates for migration flows between regions for ACS are available in American FactFinder beginning with the 2004 ACS. Use either Subject Table S0702 or Detailed Table B07101.

Decennial Census State-to-State Migration Flows
Migration questions have been asked on previous decennial censuses since 1940. Except for the 1950 Census, the time period between previous residence and current residence was 5 years instead of one year. Because of the difference in time period, Decennial Census and ACS migration estimates are not comparable.

State-to-State Migration Flow Tables are available on the Internet for Census 2000 and the 1990 Census. They are located on the Geographic Mobility/Migration Website. Tables for previous censuses are available in various publications published by the U.S. Census Bureau.

Some of the publications are available in pdf format on the Census Website. Printed copies of the publications are available at Federal depository libraries.

Migration Flows for Geography Below the State Level
Inmigration and outmigration data are available for published geographies in American FactFinder. Detailed tables B07001 through B07013 contain geographical mobility in the past year for current residence by selected characteristics for all summary levels. The data are separated into five geographical mobility categories: Nonmovers, movers within the same county, movers from a different county within the same state, movers from a different state, and movers from abroad. Detailed tables B07401 through B07413 contain geographical mobility in the past year for residence 1 year ago by selected categories for some summary levels. The data are separated into four categories: Nonmovers, movers within the same county, movers to a different county within the same state, and movers to a different state. Tables dealing specifically for Puerto Rico have a -PR suffix and slightly different geographical mobility categories.

County-to-county migration flow tables containing 2005-2009 5-year ACS data are now available. They can be found on the ACS County-to-County Migration Flows page of the Census Geographical Mobility/Migration website. Besides the county-to-county data, flows between minor civil divisions (mcd) are available for the 12 states where mcd serve as general-purpose local governments.

Other Sources
The Population Estimates Program publishes annual population estimates using various administrative and survey data. The program produces population, population change, and estimated components of change files for the nation, states, counties, metropolitan and micropolitan areas, and combined statistical areas as part of the datasets available for download. The files contain estimates for net internal and net international migration.

• ACS Background Information
• ACS Public Use Microdata Sample (PUMS) Files Information
• Population Estimates Program