Figures shown include total county in-migration and outmigration, along with counties where residents are moving to or from. Please note that the IRS does not publish individual county-to-county migration flow data if there are fewer than 10 tax returns.
Exemptions claimed on tax returns are used to approximate numbers of residents moving to or from a county. Tax returns serve as a proxy for numbers of households. Aggregate totals for adjusted gross income are also shown. Of course, the IRS data is not without its limitations, most notably that not all people file tax returns.
The IRS bases its reported figures on address changes on individual income tax returns over consecutive years. This dataset is not directly comparable to years prior to 2011 because of a few recent methodological changes. The IRS reports that its migration figures are now based off an entire year of data, instead of a partial year. A different process for matching tax returns is also now used, yielding greater numbers of matching returns.
Last Updated: Oct. 12, 2017