San Mateo County, CA → Contra Costa County, CA
Reported tax-filing households, individuals, and adjusted gross income that moved from San Mateo County, CA to Contra Costa County, CA, 2022–2023.
Households moved
1,313
People moved
2,428
Reported AGI moved
$206.37M
Avg. AGI per migrating return
$157,176
Avg. household size
1.85
Reported county-pair flows
1
IRS migration data does not represent every U.S. resident (non-filers are underrepresented), a mailing address does not always equal a physical residence, and AGI reflects Year 2 tax returns without proving income was earned after arrival. Use “income moved” or “reported AGI moved,” not “economic impact created.”