A buyer who has run the numbers on a Foster City home has almost always run them off the seller's current tax bill. That bill is a snapshot of what the seller pays. It is not what the buyer will pay. Between the base 1% Prop 13 rate, a citywide general obligation bond, and two school district parcel taxes, a Foster City parcel carries three voter-approved add-ons that parcels a mile away in unincorporated San Mateo, Burlingame, or Belmont do not.
Each of the three has a transaction-mechanic wrinkle that shows up after close, not before. Understanding them ahead of contingency removal is the difference between a supplemental bill that is expected and one that isn't.
The Base Rate Is the Same. The Add-Ons Aren't.
Every parcel in San Mateo County pays roughly 1% of assessed value under Proposition 13, plus voter-approved indebtedness and special charges layered on by local districts and cities. The San Mateo County Tax Collector states this plainly: special charges are added to the tax bill by local districts, not by the county.
The Foster City stack, at the parcel level, includes three items a neighboring parcel a few blocks away will not see:
| Line item | Who levies it | Approximate current amount |
|---|---|---|
| Measure P levee bond | City of Foster City | ~$40 per $100,000 of assessed value, annually, through the 30-year bond term |
| Measure B parcel tax | San Mateo-Foster City School District | $139.50 per parcel per year |
| Measure V parcel tax | San Mateo-Foster City School District | $357.80 per parcel per year, indexed to inflation over a nine-year term |
The effective property tax rate in Foster City averages about 1.22% of assessed value, slightly below the county average of 1.25%. The number is unremarkable in the aggregate. The composition is not.
Line Item One: Measure P and the Reset at Close
Foster City voters passed Measure P in 2018 with roughly 81% support, authorizing a $90 million general obligation bond to raise and strengthen the levee that surrounds the city's outer bay-front perimeter. The city's own materials describe the cost as approximately $40 per $100,000 of assessed property value annually for 30 years, in place of the estimated $2,000 to $3,000 or more per year in mandatory flood insurance that a FEMA flood-zone designation would have required.
Here is the wrinkle. The assessment is calculated on the parcel's assessed value, and Prop 13 resets assessed value at the change of ownership to the new purchase price. A seller carrying a 1998 base year is paying the Measure P share on a fraction of what the property will trade for. The buyer will pay it on the full purchase price, phased in through the first supplemental tax bill after close. On a $2.16 million single-family purchase, which was the Foster City single-family median in June 2026 per MLSListings, the Measure P share alone lands around $860 a year at the new basis, not the seller's basis. It is a small number in the context of the transaction and a real one in the context of the first supplemental.
Cross the city line into Burlingame or unincorporated San Mateo and this line item is not on the bill at all.
Line Item Two: Measures B and V, and the Exemption That Doesn't Transfer
The San Mateo-Foster City School District covers only the cities of San Mateo and Foster City. A buyer moving from Burlingame, Belmont, Redwood City, or Hillsborough enters a new parcel tax district at close. The district currently collects two overlapping parcel taxes, Measure B and Measure V, at exemption values of $139.50 and $357.80 respectively for the current cycle, which together add just under $500 per parcel per year. Measure V, approved in November 2018 at $298 per parcel with an inflation escalator, is the reason the number has climbed above its original ballot figure.
Owners aged 65 and over can apply for an exemption from both. The exemption is administered by the district at 1170 Chess Drive, not by the county, and the application must be submitted for each parcel tax cycle by the district's June deadline. The exemption does not follow the deed. A senior buyer purchasing from another senior does not inherit the seller's exemption. They must apply on their own, in their own name, and if they close after the June cutoff they will pay both parcel taxes for the first year regardless of age.
The mechanic to flag in escrow is simple. Confirm on the preliminary tax bill whether the current owner is exempt, because a supplemental will assess the parcel taxes without exemption once ownership changes, and a senior buyer who assumes the exemption transfers will be surprised.
Line Item Three: Why the Flood Zone Question Still Comes Up
The Foster City Levee Improvements Project reached final completion in February 2024, designed by Schaaf & Wheeler Consulting Civil Engineers and constructed by Shimmick Construction. The city's public works page documents that the improved levee restored FEMA accreditation and is engineered for sea level rise projections to the year 2100.
For a buyer, the practical consequence is that Foster City parcels sit in Zone X Protected by Levee rather than a Special Flood Hazard Area, which is what keeps federally-backed mortgages from triggering mandatory NFIP flood insurance. The disclosure question, though, has not gone away. Natural Hazard Disclosure reports still describe the levee and the flood history. Lenders and insurance underwriters still ask. And FEMA's own guidance is clear that a LOMA or LOMR removes the federal purchase requirement but leaves the mortgage lender the prerogative to require flood insurance regardless, and that more than 25% of flood claims come from properties outside the SFHA.
Two moves worth making before contingencies come off. Confirm the current FIRM designation for the specific parcel through the county or a FEMA Letter of Map Amendment record rather than the citywide press release. And ask the buyer's lender in writing whether they will require a flood policy despite the Zone X designation. Lender policies vary and the answer belongs in the file before the loan contingency is removed.
What to Ask Escrow to Pull Before Contingencies Come Off
Preliminary tax bill. Confirm the current Measure P assessment amount, the current Measures B and V line items, and whether the current owner is taking the senior exemption.
First supplemental estimate. Ask the title company to run a supplemental estimate at the purchase price so the reset on the 1% base rate and the Measure P share is on paper, not a surprise.
Parcel-specific flood determination. Request the current FEMA flood zone determination for the property, not the citywide designation, and forward it to the lender in writing.
School parcel tax exemption timing. If the buyer is 65+ at close, note the district's June application deadline and calendar the application immediately after recording.
Frequently Asked Questions
Do these line items apply to condominiums and townhomes the same way? Measure P applies to any taxable parcel inside Foster City limits, so an attached-home parcel pays it on the same per-$100,000-of-assessed-value basis. Measures B and V are levied per parcel, meaning a townhome on its own APN pays the full amount while a condominium unit sharing a master parcel may see the tax allocated differently through the HOA. Confirm the treatment on the specific APN.
Does Measure P end when the bond is paid off? The 2018 authorization runs 30 years. The rate can be adjusted downward if actual interest rates on the bond sale come in lower than projected, per the city's own resolution establishing the assessment. Absent early defeasance, the assessment sits on Foster City bills into the mid-2040s.
If the levee is FEMA-accredited, why do some lenders still require flood insurance? A LOMA or LOMR removes the federal flood insurance purchase requirement, but individual lenders retain the right to require a policy as a condition of financing regardless of zone designation. This is why the answer belongs in writing from the specific lender on the specific parcel before removing the loan contingency.
Foster City rewards buyers who read the tax bill line by line, not top line. If you're weighing a Foster City purchase against a neighboring Peninsula city and want the supplemental math run against a specific address, along with a plain-English read of the preliminary title and NHD before contingencies come off, Julie Flouty is available for a consultation. Let's Connect.
