In 2019, 23,543 people moved to Contra Costa County from within the state, according to migration data from the Internal Revenue Service.
This is an increase over the year before, when 21,032 people migrated to Contra Costa County from elsewhere in the state.
The number of people moving to Contra Costa County is offset by the 30,732 residents who left the area during the same year.
There were 28,634 people who left the year before.
Migration data for the U.S. is based on year-to-year address changes reported on individual income tax returns filed with the IRS.
According to the U.S. Census Bureau, most U.S. regions saw their numbers shrink.
The Northeast region of the U.S. suffered the greatest losses, while the Midwest saw population growth.
The U.S. Census Bureau found migration within the country mainly flows to the South, with many people moving to areas of Florida and Texas.
| Years | Inflow | Outflow | Domestic Migration |
|---|---|---|---|
| 2017-2018 | 21,940 | 29,489 | -7,549 |
| 2018-2019 | 21,032 | 28,634 | -7,602 |
| 2019-2020 | 23,543 | 30,732 | -7,189 |
