County ZIP codes · California · FIPS 06081
San Mateo County, CA ZIP Codes
San Mateo County, California has 38 ZIP codes (Census 2020 ZCTA-county file; GeoNames postal codes, October 2026): 31 residential and 7 for PO boxes or a single organization. 30 of the residential ones lie mainly in San Mateo County and 1 mainly in a neighboring county; 2 cross the county line. Median household income ranges from $116,760 in 94063 (Redwood City) to $250,000 or more in 3 ZIP codes at the Census top code (Census Bureau, ACS 2020-2024).
- ACS2020-24
- Census2020
Where are the ZIP codes of San Mateo County?
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).
How different are its ZIP codes?
The middle half of its ranked ZIP codes (1,000+ people living in households) report median household incomes between $136,733 and $196,882. 3 report $250,000 or more, the Census top code.
They carry 24 postal town names.
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B19013).
All 31 residential ZIP codes in San Mateo County
30 ZIP codes lie mainly in San Mateo County; 1 more reaches into it from a neighboring county and follows the first table.
| In this county | ||||||
|---|---|---|---|---|---|---|
| 94080 | South San Francisco | 64,761 | 6,363 | $137k | $1.19M | 100% |
| 94015 | Daly City | 64,091 | 11,332 | $127k | $1.17M | 100% |
| 94014 | Daly City | 45,315 | 7,090 | $123k | $1.04M | 100% |
| 94403 | San Mateo | 43,276 | 7,683 | $175k | $1.75M | 100% |
| 94010 | Burlingame | 43,025 | 2,846 | $197k | $2M+ | 100% |
| 94066 | San Bruno | 42,728 | 7,051 | $141k | $1.21M | 100% |
| 94025 | Menlo Park | 40,721 | 4,868 | $217k | $2M+ | 100% |
| 94044 | Pacifica | 37,274 | 2,470 | $160k | $1.25M | 100% |
| 94061 | Redwood City | 37,048 | 9,595 | $146k | $1.9M | 100% |
| 94404 | San Mateo | 35,881 | 8,249 | $192k | $1.71M | 100% |
| 94401 | San Mateo | 35,295 | 11,345 | $122k | $1.18M | 100% |
| 94063 | Redwood City | 34,433 | 5,296 | $117k | $1.04M | 100% |
| 94070 | San Carlos | 30,447 | 4,974 | $240k | $2M+ | 100% |
| 94002 | Belmont | 27,534 | 4,896 | $204k | $2M+ | 100% |
| 94062 | Redwood City | 25,759 | 398 | $233k | $2M+ | 100% |
| 94402 | San Mateo | 25,475 | 5,045 | $173k | $2M+ | 100% |
| 94030 | Millbrae | 22,689 | 6,725 | $164k | $1.93M | 100% |
| 94019 | Half Moon Bay | 14,419 | 241 | $154k | $1.56M | 100% |
| 94065 | Redwood City | 11,673 | 5,088 | $216k | $1.81M | 100% |
| 94027 | Atherton | 7,002 | 1,393 | $250k+ | $2M+ | 100% |
| 94028 | Portola Valley | 6,531 | 377 | $250k+ | $2M+ | 81% |
| 94005 | Brisbane | 4,692 | 1,024 | $156k | $1.23M | 100% |
| 94018 | El Granada | 3,834 | 6,622 | $230k | $1.43M | 100% |
| 94037 | Montara | 2,917 | 530 | $234k | $1.58M | 100% |
| 94038 | Moss Beach | 2,683 | 452 | $100k | $1.12M | 100% |
| 94020 | La Honda | 1,694 | 40 | $250k+ | $996k | 100% |
| 94060 | Pescadero | 1,465 | 20 | $128k | $1.4M | 100% |
| 94021 | Loma Mar | 321 | 29 | $250k+ | $1.07M | 100% |
| 94074 | San Gregorio | 126 | 5 | $250k+ | – | 100% |
| 94128 | San Francisco | no residents | 0 | – | – | 100% |
Partly in San Mateo County
| In this county | ||||||
|---|---|---|---|---|---|---|
| 94303 | Palo Alto | 46,879 | 5,555 | $152k | $1.83M | 33% |
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; county shares by land area (Census 2020 ZCTA-county relationship file).
Which ZIP codes cross the county line?
2 ZIP codes of San Mateo County extend into another county. A ZIP code follows mail routes, not county borders.
| ZIP | In San Mateo | Elsewhere |
|---|---|---|
| 94303 | 33% | Santa Clara County 67% |
| 94028 | 81% | Santa Clara County 19% |
Source: U.S. Census Bureau, 2020 ZCTA-county relationship file (shares of land area).
PO Box and single-organization ZIP codes
Source: GeoNames postal codes (CC BY 4.0).
Which first three digits do San Mateo County's ZIP codes use?
The first three digits of a ZIP code name the sectional center, the mail processing plant that sorts it. San Mateo County's ZIP codes use 4 prefixes: 940, 941, 943 and 944.
| Prefix | Sectional center | Here | All codes |
|---|---|---|---|
| 940 | San Francisco, CA (SCF 940) | 31 | 45 |
| 941 | San Francisco, CA (SCF 940) | 1 | 51 |
| 943 | San Francisco, CA (SCF 940) | 1 | 7 |
| 944 | San Francisco, CA (SCF 940) | 5 | 5 |
Source: U.S. Postal Service, labeling list L005 (3-digit ZIP Code prefix groups, SCF sortation), effective October 1, 2026.