Market insights · California
San Mateo County, CA: growth, migration and housing
San Mateo County has 743,568 residents, down 2.5% since 2020 (+0.4% in the last year). In 2022–2023, 21,292 households moved in and 23,959 moved out (-2,667 net), while a net $891.3M of income left. Median household income is $158,855, the median home $1,559,600 and median rent $2,922 a month.
In California: 39th of 58 counties for 5-year population growth · 40th of 58 counties for net in-migration (per resident) · 2nd of 58 counties for median household income · 1st of 58 counties for median home value.
Where new residents came from
Top counties by households (tax returns) moving to San Mateo County, 2022–2023 (IRS).
| From | Households (tax returns) | Their income (AGI) |
|---|---|---|
| San Francisco County, CA | 4,514 | $798.9M |
| Santa Clara County, CA | 3,879 | $975.6M |
| Alameda County, CA | 2,026 | $301.6M |
| Los Angeles County, CA | 977 | $139.4M |
| Contra Costa County, CA | 839 | $101.0M |
| San Diego County, CA | 439 | $50.7M |
| Sacramento County, CA | 352 | $28.5M |
| King County, WA | 329 | $77.0M |
Where leavers went
Top counties by households leaving San Mateo County, 2022–2023 (IRS).
| To | Households (tax returns) | Their income (AGI) |
|---|---|---|
| Santa Clara County, CA | 3,874 | $1010.5M |
| San Francisco County, CA | 3,710 | $609.5M |
| Alameda County, CA | 2,498 | $361.5M |
| Contra Costa County, CA | 1,313 | $206.4M |
| Los Angeles County, CA | 900 | $128.3M |
| Sacramento County, CA | 635 | $65.9M |
| San Diego County, CA | 600 | $133.9M |
| San Joaquin County, CA | 416 | $37.2M |
BizyFi in San Mateo County
27 companies in the BizyFi directory are based here. Search them on the company map (company names with a free account), or browse California companies.
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Sources: U.S. Census Bureau population estimates (vintage 2025), American Community Survey 5-year (2024), and IRS Statistics of Income county-to-county migration data (2022–2023). Migration counts are tax returns (roughly households) moving between U.S. counties; the IRS suppresses very small flows. Growth rates, per-1,000 figures, rent share and state ranks are BizyFi calculations. Data updated 2026-10-17. This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.