San Mateo County property record for 421 W 39th Ave, San Mateo, CA 94403
| Property Type | Single Family Home |
|---|---|
| Details | 3 bd · 2 ba · 1,670 sqft · built 1957 |
| Lot Size | 0.133 acres (5,784 sqft) |
| Owner | 2 Trust Names on File |
| Last Sale | $365,000 (Apr 1996) |
| Tax Bill | $9,556 (2025) |
| Flood Zone | Zone X (minimal risk) |
| APN | 042-101-040 |
| Primary APN | 042-101-040 |
|---|
| Bedrooms | 3 Beds |
|---|---|
| Full Baths | 2 Baths |
| Total Rooms | 6 Rooms |
| Stories | 1 Story |
| Building Area | 1,670 sqft Living Area |
| Gross Area | 2,330 sqft |
| 1st Floor Area | 1,670 sqft |
| Basement Area | 660 sqft |
| Family Room | Family Room |
| Fireplaces | 1 Fireplace |
| Fireplace | Fireplace |
| Year Built | Built 1957 |
|---|---|
| Effective Year Built | Effective 1957 |
| Architectural Style | Ranch |
| Exterior Material | Wood Siding |
| Construction Type | Brick |
| Foundation Type | Pier/Post & Beam |
| Roof Material | Composition Shingle |
| Lot Area | 5,784 sqft (0.133 acres) |
| Lot Dimensions | 100 ft deep x 58 ft wide |
| View / Lot | Corner |
| Garage Type | Basement |
| Garage Area | 660 sqft |
| Parking Spaces | 2 Parking Spaces |
| Cooling System | Central |
|---|---|
| Heating System | Central |
| Sewer | Municipal |
| Water Source | Commercial |
| Street Address | 421 W 39TH AVE |
|---|---|
| City | SAN MATEO |
| State | CA |
| Zip | 94403-4334 |
| Property Category | Residential |
| Property Type | Residential > Single Family > Home |
| Local Zoning Code | R10006 |
| Legal Description | LOT 1 BLOCK 4 ROLLING HILLS RSM 26/26 CITY OF SAN |
| Legal Subdivision | ROLLING HILLS |
| Legal Block | 4 |
| Legal Lot Number | 1 |
| Jurisdiction | SAN MATEO CA |
| Township / Civil Division | SAN MATEO |
| Census Block Group | 3 |
| Census Block | 3011 |
| Census Tract | 607100 |
421 W 39th Ave is held in a trust since February 2026.
Source: San Mateo County records, as of October 19, 2026
| Owner of Record | 2 Trust Names on File |
|---|---|
| Mailing Address | 9 GELLERT DR, SAN FRANCISCO, CA 94132-1231 |
| Owner Type | Company |
| Vesting | Trust, Revocable Trust |
Owner names and exact recorded amounts are on file and can be viewed instantly on this page with a free 10-day trial.
| Deed Names | 2 Names on Deed |
|---|---|
| Last Sale | Apr 30, 1996 · Amount on File |
| Deed Sale | Apr 30, 1996 · Amount on File |
| Deed Document Number | 199652528 |
| Last Transfer Date | Feb 2, 2026 |
| Transfer Doc | 0000006417 |
| Record Updated | Oct 29, 2026 |
The 2025 property tax bill for 421 W 39th Ave was $9,556.
Source: San Mateo County assessment roll, as of July 15, 2026
| Type | Name |
|---|---|
| State | California |
| County | San Mateo County |
| Municipality | San Mateo City |
| Elementary School District | San Mateo-Foster City Elementary School District (KG - 08) |
| Secondary School District | San Mateo Union High School District (09 - 12) |
| Year | Tax Bill | Assessed Value | Assessed Market Value |
|---|---|---|---|
| 2026 | $618,466 (+2%) Land $309,233 Building $309,233 | ||
| 2025 | $9,556.00 | $606,340 Land $303,170 Building $303,170 | |
| 2023 | $8,658.00 (+0.41%) | $582,798 Land $291,399 Building $291,399 | $1,558,620 |
| 2022 | $8,623.00 |
Assessed value and assessed market value are set for property tax purposes and are not market price estimates.
FEMA maps place 421 W 39th Ave in Zone X, an area of minimal flood risk, though there have been 1 flood claim nearby since 2006.
Source: FEMA National Flood Hazard Layer, effective September 10, 2026 · OpenFEMA NFIP redacted claims and policies, as of September 2026
| FEMA Flood Zone | Zone X minimal risk |
|---|---|
| Flood Insurance Requirement | Not required lenders may require it |
| Nearby Flood Policies | 1 in force |
| Nearby Flood Claims | 1 (2006) |
| Claims Outside the SFHA | 1 of 1 |
| Most Recent Claim | Jan 2006 · Severe Storms, Flooding, Mudslides, And Landslides |
Values are read at the parcel center point; flood claims are located to the census block group, not this parcel; lenders make the official flood determination.
The area around 421 W 39th Ave has no burnable land within ember reach, so its wildfire risk is not rated.
Source: USDA Forest Service Wildfire Risk to Communities (2nd edition), as of 2024
| Wildfire Risk | Not rated no burnable land within ember reach |
|---|
Values cover an area roughly 900 ft across, not the parcel itself; insurers use their own ratings.
Source: EPA Safe Drinking Water Information System, as of September 2026
| Water System | CALIFORNIA WATER SERVICE - SAN MATEO private · serves 103,536 people · EPA ID CA4110008 |
|---|---|
| Water Source | Purchased surface water from SAN FRANCISCO REGIONAL WATER SYSTEM |
| Last State Inspection | Mar 2025 |
| Lead | 4 ppb (2023–2025) action level 15 ppb |
| Water Quality | None last 10 years |
|---|---|
| Treatment and Procedure | None last 10 years |
| Monitoring and Reporting | None last 3 years |
Results are for the whole water system, not water tested at this address; lead at the tap also depends on the building's own pipes.
Source: FCC Broadband Data Collection, based on 572 locations within half a mile, as of December 31, 2025
| Provider | Max Down / Up (Mbps) |
|---|---|
| Sonic Telecom Fiber | 10,000 / 10,000 |
| AT&T Fiber · Fixed Wireless, DSL in parts of the area | 5,000 / 5,000 |
| Xfinity Cable | 2,000 / 250 |
| Astound Broadband Cable · Fiber in parts of the area | 1,500 / 50 |
| Verizon Fixed Wireless | 300 / 20 |
| Etheric Networks Fixed Wireless | 250 / 100 |
May also be available: T-Mobile.
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