The interactive map traces population gain and loss on the county level in tax year 2020 compared with tax year 2019. Data are limited to individuals who filed income tax returns with the IRS (about 70%-80% of the entire population). Net Migration is calculated as the difference between the inflow migration to the county and the outflow migration from the county. Net Migration is limited to domestic migrations, so migrations to and from foreign countries are excluded. Migrations with negative numbers in IRS source data are treated as missing values.

Source: IRS Migration Data and AEI Housing Center