ZIP Code 94403 · San Mateo, California
San Mateo County · 17,660 counted · 4 districts
Each percentage here is a share of the 17,660 homes counted in ZIP Code 94403, not the chance that any one address is in that district. Enrollment follows the street: two houses on opposite sides of the same road can be in different districts, and only the district office can say which.
The districts named for the early grades in ZIP Code 94403, San Mateo, California are not the districts named for high school, and the set changes in both directions: 2 districts arrive for high school that no elementary answer names, and 2 run the early grades and stop. 4 districts hold the 17,660 homes counted here between them, and San Mateo Union High and San Mateo-Foster City Elementary hold the most of them, 16,402 homes each. The largest share is high enough that one name is right for most of the homes counted and wrong for the other 1,258: 1,258 homes with Belmont-Redwood Shores Elementary.
The early grades are split between two districts
2 districts hold a measurable share of ZIP Code 94403 at this level. San Mateo-Foster City Elementary is the largest with 16,402 homes; the smallest of them holds 1,258 homes. San Mateo-Foster City Elementary and Belmont-Redwood Shores Elementary are named here for grade school and not for high school.
Every track below is 35 cells long and stands for all 17,660 homes counted in ZIP Code 94403, so one cell is 505 homes, rounded to the nearest whole cell. Cells lit solid are the homes one district holds, and the unlit cells are the homes held by the other districts in the same list.
- San Mateo-Foster City Elementary School District16,402 of 17,660 homes93%
- Belmont-Redwood Shores Elementary School District1,258 of 17,660 homes7.1%
High school is split between two districts
2 districts hold a measurable share of ZIP Code 94403 at this level. San Mateo Union High is the largest with 16,402 homes; the smallest of them holds 1,258 homes. San Mateo Union High and Sequoia Union High are named here for high school and not for the early grades.
- San Mateo Union High School District16,402 of 17,660 homes93%
- Sequoia Union High School District1,258 of 17,660 homes7.1%
Have a street address?
A ZIP Code names every district that can serve the area; a street address settles which one serves a home. The Census Bureau geocoder takes an exact address and returns its school districts from the current boundary files, free and with no account.
Check an exact address with the Census Geocoder
Then confirm it with the district office. Each district named here, with its NCES district ID, website and phone:
- San Mateo Union High School District NCES ID 0634980 smuhsd.org (650) 558-2299
- San Mateo-Foster City Elementary School District NCES ID 0634920 smfcsd.net (650) 312-7700
- Belmont-Redwood Shores Elementary School District NCES ID 0604530 brssd.org (650) 637-4800
- Sequoia Union High School District NCES ID 0636390 seq.org (650) 369-1411
The set of names changes in both directions
San Mateo Union High and Sequoia Union High are named for high school here and for no elementary grades, and San Mateo-Foster City Elementary and Belmont-Redwood Shores Elementary run the early grades and no more. An address on the wrong street can therefore change district at the change of grade and land in a district that was never part of its elementary answer, while a neighbor two blocks away keeps one name the whole way through.
What one district name costs in 94403
A lookup that answers ZIP Code 94403 with one district name has to pick one of the names below and drop the rest. Measured against the 17,660 homes counted here, for the early grades it is wrong for 1,258 homes and for high school it is wrong for 1,258 homes. That is the whole difference between this page and a one-line answer: the same federal file, read to the end instead of to the first row.
The districts that reach into 94403
The districts named above are not alike in size or in reach. San Mateo Union High touches 15 ZIP Code areas in all and holds 16,402 homes inside this one; Belmont-Redwood Shores Elementary touches 7 areas. Not one of them is ever the only district in a ZIP Code area anywhere in the country: every postal area they touch, they share with somebody.
- San Mateo Union High School District16,402 of 17,660 here · 15 ZIP areas in all
- San Mateo-Foster City Elementary School District16,402 of 17,660 here · 9 ZIP areas in all
- Belmont-Redwood Shores Elementary School District1,258 of 17,660 here · 7 ZIP areas in all
- Sequoia Union High School District1,258 of 17,660 here · 14 ZIP areas in all
Where San Mateo-Foster City Elementary goes from here
San Mateo-Foster City Elementary School District runs kindergarten through grade 8, and it shares 4 of the 9 ZIP Code areas it touches with neighbors, holds under half a percent of the homes in the remaining 5, and is the only district in none of them. Inside its own boundary it holds 55,830 homes over 28 square miles; the part of it counted in ZIP Code 94403 is 16,402 of those. The district it shares the most postal ground with is San Mateo Union High School District, across 4 ZIP Code areas.
How 94403 compares in California
Across California the boundary file names more than one district in 996 of the 1,788 ZIP Code areas it names a district for, 56% of them, and 3 areas in the state have no high school district named for part of their homes. Counting the districts named at either level, 150 areas in California name more than this ZIP Code does and 1,489 name fewer. Nationally more than one district is named in 53% of 33,555 areas.
Look up 94403 again, or look up another ZIP Code
The lookup holds every ZIP Code area in the country with homes in it, including the ones with no page of their own. Opening it at 94403 recomputes the same 17,660 homes from the same snapshot, and typing five other digits answers for somewhere else. No server is asked for the answer: the whole index travels with the lookup page itself.
What to do next
Ask the district office to confirm your street address: look on its site for a school locator, a find my school tool or an attendance zone map, or call the office.
A ZIP Code is a set of mail delivery routes, not a boundary: 1,258 of the 17,660 homes counted in 94403 sit outside each of the 2 districts tied for the most of them, and the line runs along streets rather than around the postal area.
District websites and phone numbers here come from the NCES Common Core of Data directory, 2024-25 school year, filed under the same district ID as the Census boundary files. Where it lists no usable website, none is printed rather than guessed.
What this site can hand you instead:
If a house purchase depends on the answer, ask the district itself for written confirmation of that exact address. A listing is not a district record, and neither is this page.
Where these numbers come from
The homes were counted in the 2020 Census and the district lines are the 2026 boundary file, so a fast-growing area may have changed since; ZIP Codes here are the Census Bureau's ZIP Code Tabulation Areas; a share is a share of homes, not the chance that one address is in a district; and a district is not a school attendance zone. Every source, file and caveat is on the method page.