Choropleth Map

The choropleth map on the first page shows every U.S. state or county colored by the selected metric for a single year. Use the controls above the map to:

• Level — switch between State and County granularity.
• Year — drag the slider to view any tax year from 2007–2008 through 2022–2023.
• Category & Statistic — choose a data category (Population, Households, or AGI) and then pick a specific statistic within that category.
• Zoom / Pan — zoom in and pan horizontally or vertically to focus on a specific region.

Click a state or county, and the map will re-shade to show migration flows to and from that region. Click that region again to deselect.

Individual Trend Chart

Scroll down (or click the ↓ arrow) to the Individual Trend page. Here you can search for any state or county, Add it to the chart, and compare up to twelve regions on a single time-series plot. Change the metric at any time; the chart re-renders instantly.

Pairwise Comparison Chart

The Pairwise Comparison page lets you pick two regions (Region A and Region B) and chart the flow between them over time. You can add up to twelve pairs simultaneously. The directional labels (A → B, B → A) help clarify which direction each metric refers to.

AGI (Adjusted Gross Income)

Total gross income minus specific deductions, as reported on IRS tax returns. In this dataset, AGI values are expressed in thousands of dollars.

Choropleth Map

A thematic map in which areas are shaded in proportion to a statistical variable, making it easy to compare magnitudes across regions at a glance.

County Equivalent

An administrative division treated the same as a county for census and IRS purposes. Examples include independent cities (e.g., Carson City, NV), parishes (Louisiana), and boroughs (Alaska).

FIPS Code

A numeric code assigned by the Federal Information Processing Standards to uniquely identify every state (2 digits) and county (5 digits) in the U.S.

Household

A tax return filing unit. One household may include one or more individuals. In the IRS SOI data, this corresponds to the number of returns (n1).

Inbound Rate

The proportion of total migration volume that is inbound. Calculated as inflow ÷ (inflow + outflow). A rate above 50 % indicates the region attracts more migrants than it loses.

Inflow

The number of people, households, or dollars (AGI) moving into a region during a given tax year.

Inflow Rate

A region's inflow expressed as a percentage of the region's total population, number of households, or AGI.

Inflow Share

When unselected, the region's share of the total national inflow of people, households, or dollars (AGI). When selected, the region's share of the selected region's total inflow.

IRS SOI (Statistics of Income)

A division of the Internal Revenue Service that publishes statistics derived from tax return data, including the county-to-county migration dataset used by this website.

Net Inflow / Net Outflow

The difference between inflow and outflow. Net inflow = inflow − outflow (positive means the region gained). Net outflow = outflow − inflow (positive means the region lost).

Outbound Rate

The proportion of total migration volume that is outbound. Calculated as outflow ÷ (inflow + outflow). Equal to 1 − inbound rate.

Outflow

The number of people, households, or dollars (AGI) moving out of a region during a given tax year.

Outflow Rate

A region's outflow expressed as a percentage of the region's total population, number of households, or AGI.

Outflow Share

When unselected, the region's share of the total national outflow of people, households, or dollars (AGI). When selected, the region's share of the selected region's total outflow.

Population

The number of individual tax exemptions (n2) on migrating returns. This is used as a proxy for the number of people who moved.

Avg AGI Ratio (In-to-Out / Out-to-In)

The ratio of the average AGI per migrant (individual or household) moving in to the average AGI per migrant moving out, or vice versa. A ratio above 1.0 for in-to-out means in-movers have higher average incomes than out-movers.

Tax Year

The IRS filing year associated with a migration record. A label such as "2021–2022" means the data compares addresses on returns filed in 2021 with those filed in 2022.