ZIP code 94403: San Mateo, CA
ZIP code 94403 is in San Mateo, in San Mateo County, California. It is in California's 15th congressional district. Its state senate district is State Senate District 13; its state house district is Assembly District 21.
See it on the mapAll of California
City and county
| City or town | Share of ZIP residents |
|---|---|
| San Mateo | 100% |
| County | Share of ZIP residents |
|---|---|
| San Mateo County | 100% |
| Town or county subdivision | Share of ZIP residents |
|---|---|
| San Mateo CCD | 100% |
Congressional district
| Congressional district | Share of ZIP residents |
|---|---|
| California's 15th congressional district (CA-15) | 100% |
Elected officials
| Office | Member | Contact | Share of residents |
|---|---|---|---|
| Mayor | Adam Loraine | 650-522-7522 | 100% |
| U.S. Representative (CA-15) | Kevin Mullin (D) | 202-225-3531 | 100% |
| U.S. Senator | Adam B. Schiff (D) | 202-224-3841 | statewide |
| U.S. Senator | Alex Padilla (D) | 202-224-3553 · contact form | statewide |
| State Senator (State Senate District 13) | Josh Becker (Democratic) | 650-233-2724 | 100% |
| Assembly Member (Assembly District 21) | Diane Papan (Democratic) | 650-349-2200 | 100% |
Elected in 2024 under CA's previous congressional map; this district's lines changed for the 120th Congress (seated January 3, 2027).
Officials serving now (members of Congress until January 3, 2027). Sources: Mayors: Open States (public domain); State legislators: Open States (public domain); Members of Congress: the @unitedstates project, congress-legislators (CC0).
Local government
- San Mateo website: https://www.cityofsanmateo.org/
- San Mateo laws: search for the San Mateo, California code of ordinances
- San Mateo County website: https://smcgov.org
- San Mateo County laws: search for the San Mateo County, California code of ordinances
State legislative districts
| State senate district | Share of ZIP residents |
|---|---|
| State Senate District 13 | 100% |
| State house district | Share of ZIP residents |
|---|---|
| Assembly District 21 | 100% |
Voting precincts
15 voting precincts overlap ZIP 94403. Map them, with each precinct's share of the ZIP's residents.
Get this in your AI agent
Your agent can get these cities, counties, districts and precincts with their shares, and their GeoJSON boundaries, from Boundary Atlas. Add https://atlas-production-d344.up.railway.app/mcp to Claude, ChatGPT, Cursor or Codex (free, no key; how), then:
related_geographies(id="us:zcta:94403")
ZIP 94403 here is the Census Bureau's ZIP Code Tabulation Area, which approximates the USPS ZIP Code; PO-box-only ZIPs have none. Districts are the maps in force for the November 3, 2026 election.