Property tax is the cost buyers ask about last and are most surprised by. On Coronado, where the typical home is valued in the millions, the rules of Proposition 13 matter more than almost anywhere. This page explains them in plain English, with the numbers worked out for the island.
Property Tax Explained
Prop 13 and Prop 19 on Coronado, Explained
What buying a Coronado home does to your property tax: the new base value, the 2% cap, the homeowners’ exemption, Mills Act savings and when Prop 19 matters.
How the tax is set
California voters approved Proposition 13 on June 6, 1978. It set the base property tax at 1% of a home’s assessed value, rolled assessments back to their 1975–76 levels, and limited yearly increases in the assessed value to the rate of inflation or 2%, whichever is less. The assessed value changes in two main ways: it rises by the capped amount each year, and it is reset to market value when a home is sold or new construction is completed.
For a buyer, the practical consequence is that your tax is based on your purchase price, not the seller’s. A home a seller has owned for decades may carry a modest assessed value; when you buy it, the assessor reassesses it at the price you paid. Voter-approved bonds and special assessments are added to the 1% base, so the total is usually somewhat higher than 1%.
Worked example
The arithmetic on Coronado
A first-year bill at today’s typical Coronado value, and how it could drift over ten years.
A first-year bill and how it can change
Assumes a purchase at the typical home value in ZIP 92118 ($2,563,759, Aug 2026), a base rate of 1.00% plus 0.15% of assumed voter-approved charges (1.15% in all), assessed value rising at the 2% cap, and, for comparison, a market value rising 4% a year. An illustration, not a forecast.
| When | Assessed value | Estimated bill | Market value at 4% | Bill if reassessed then | Assessed-to-market gap |
|---|---|---|---|---|---|
| Year 1 | $2,563,759 | $29,483 | $2,563,759 | $29,483 | $0 |
| Year 2 | $2,615,034 | $30,073 | $2,666,309 | $30,663 | $51,275 |
| Year 3 | $2,667,335 | $30,674 | $2,772,962 | $31,889 | $105,627 |
| Year 5 | $2,775,095 | $31,914 | $2,999,236 | $34,491 | $224,140 |
| Year 10 | $3,063,929 | $35,235 | $3,649,029 | $41,964 | $585,099 |
The first-year bill on $2,563,759 is about $29,483 ($2,457 a month). Because the assessed value can rise only 2% a year, in this illustration the bill in year 10 is about $35,235, while a buyer who purchased that year at the higher market value would start at about $41,964. Special taxes such as Mello-Roos, the homeowners’ exemption and any temporary reductions are not included.
The Coronado twist: historic homes and the Mills Act
Coronado has a large stock of historic homes, and the city runs a Mills Act program for owners of designated historic resources in residential zones. Under a Mills Act contract, the owner receives a reduction in property taxes in exchange for preserving the home. The city describes contracts as lasting 10 years and staying with the property when it is sold, and reports that more than 150 Coronado properties benefit. Because the savings depend on the assessed value, they can be significant on a high-value home, and they can also be worth asking about if you are considering buying a designated house.
If you are looking at an older home, ask whether it is already designated, whether a Mills Act contract is in place, and what the contract requires. A title company or the county assessor can estimate the effect on the tax bill before you make an offer.
The homeowners’ exemption
If you will live in the home, California’s homeowners’ exemption reduces the assessed value by $7,000, which is worth roughly $80 a year at a tax rate of about 1.15%. It is a one-time filing with the county assessor (Form BOE-266); to receive the full exemption in the first year, the first claim is due by February 15. The exemption stays in place until something changes, and a new owner files their own claim. It does not apply to a second home or a rental.
When the bill arrives
The regular bill is paid in two installments: the first is due November 1 and delinquent after December 10, and the second is due February 1 and delinquent after April 10. If your lender collects property tax in an escrow account, it usually pays these for you. After a purchase, the assessor also issues a supplemental bill for the difference between the old assessed value and your new one, covering the part of the fiscal year that remains after closing, and it is often mailed to you directly rather than paid from escrow. A supplemental assessment can be appealed within 60 days of the mailing date of the supplemental bill, according to the San Diego County Assessor.
Where Proposition 19 comes in
Proposition 19, effective in 2021, changed two things. First, when a family home passes from parent to child, the parent’s tax value carries over only if the child makes it their principal residence and only up to a limit: market value above the parent’s factored base value plus an inflation-adjusted amount (currently $1,044,586 for transfers from February 16, 2025 through February 15, 2027) is added to the assessed value. Second, homeowners who are 55 or older, severely disabled or victims of a disaster can transfer their existing tax base to a replacement home within two years, subject to limits on how many times and on the value of the replacement home.
Both are worth understanding if a Coronado home is in your family, and both are best confirmed with the assessor and an attorney or tax professional for your situation.
Common questions
Will my tax bill be based on what the seller pays?
No. A sale reassesses the property at the new market value, so the bill is based on the purchase price plus any voter-approved charges.
Can the assessed value ever go down?
Yes. If a home’s market value on January 1 is below its assessed value, an owner can ask the assessor for a temporary reduction (Proposition 8). The assessor reviews it each year.
Does the 2% cap apply to Mello-Roos?
No. Special taxes are set by the district and are not limited by Proposition 13. Ask for the exact tax bill of any home you are considering to see whether any apply.
How do I estimate the tax on a specific home?
Use the property tax estimator for a first pass and ask your title company for the actual figure.
Keep exploring
- Property tax estimator — Try your own numbers, including Mello-Roos.
- The Coronado buyer’s guide — Neighborhoods, costs and the steps to closing.
- Coronado neighborhoods — Seven areas, one page each.
- Weekly market report — Values and the buyer-versus-seller gauge.
Talk to a lender. Rates, loan programs and approvals come from lenders, not from websites or real estate agents. Talk to your own mortgage broker, or use our preferred lender, Rodrigo Ballon with CrossCountry Mortgage, at 858-735-0255. You are always free to choose any lender you like, and you can verify any lender’s license at nmlsconsumeraccess.org.
Sources
- Public Policy Institute of California: Proposition 13, 40 years later
- San Diego County Assessor: real property assessment
- San Diego County Treasurer-Tax Collector: secured property taxes
- California State Board of Equalization: homeowners’ exemption
- California State Board of Equalization: Proposition 19
- City of Coronado: Historic Preservation and the Mills Act
General information for orientation, not legal, tax, financial or appraisal advice. Details change; confirm anything that matters with the official source, your lender and your agent.