Prop 19 calculator.
Take your low property tax with you.

By Amrit Singh, REALTOR® · The Oberoi Group at Intero Real Estate · Published October 11, 2026 · Rules and tax rates checked October 11, 2026

If you’ve owned your home for a while, your property tax is probably a fraction of what a new buyer would pay for the same house. That gap is Prop 13. And the question I hear from homeowners over 55 is always the same: if I sell and buy something else, do I lose it?

Under Prop 19, often you don’t. You can take your assessed value with you to a new home anywhere in California. And if you’re inheriting your parents’ home, Prop 19 decides whether you keep their low tax or start over at today’s value.

Prop 19 in one minute

Voters passed Prop 19 in November 2020. It did two things:

• It made moving easier. Homeowners who are 55 or older, severely disabled, or who lost a home to a wildfire or natural disaster can carry their assessed value to a replacement home anywhere in California, at any price, up to three times.
• It made inheriting a low tax bill harder. Since February 16, 2021, a parent’s assessed value passes to a child only if the child moves into the family home, and only up to a cap.

Moving at 55 or older: who qualifies

• You, or your spouse who lives with you, are 55 or older on the day you sell.
• The home you sell is your main home, and so is the one you buy.
• You buy the new home, or finish building it, within two years before or after the sale.
• You haven’t already used it three times. Transfers after a wildfire or natural disaster don’t count toward the three.
• The new home can be in any California county. You file with the assessor where the new home is.

What if the new home costs more?

This is where a lot of the calculators online get it wrong, and it’s where timing makes you money.

You can buy a more expensive home and still use Prop 19. The difference gets added to your assessed value. But where “more expensive” starts depends on when you buy:

• Buy before you sell: the new home is compared with 100% of what your current home sells for.
• Buy within a year after you sell: 105%.
• Buy in the second year after you sell: 110%.

Whatever the new home costs above that line gets added to your current assessed value. That’s the method in the Board of Equalization’s own worked example: a home sold for $500,000 with an assessed value of $137,725, and a $700,000 replacement bought within the year. 105% of $500,000 is $525,000, so the extra $175,000 gets added, for a new assessed value of $312,725.

A Fremont example

Say you sell for $1,600,000, your assessed value is $450,000, and you buy a $1,800,000 home in Fremont. Here’s how the timing plays out:

Without Prop 19 that home would be assessed at $1,800,000, about $21,143 a year at Fremont’s 1.1746% rate. Selling first and buying within the next year keeps about $940 more a year than buying first, every year you own the home.

Buy first or sell first?

Prop 19 rewards selling first. Buy first and you’re on the 100% test, carrying two homes, and paying property tax on both until the old one closes. Sell first and you get 5% more room in the first year and 10% in the second, but you need somewhere to live in between. A rent back from your buyer, a short term rental or a bridge loan can cover that gap.

I map out both paths with every client before we list. The right answer depends on your cash, your lender and how much juggling you’re up for.

Inheriting your parents’ home

Before February 16, 2021, a child could inherit a parent’s home and keep the parent’s assessed value no matter what they did with it. Not anymore. Now:

• The home has to have been your parent’s main home, and you have to make it your main home within one year. Rent it out or keep it as a second home and it’s reassessed to market value.
• You file for the homeowners’ exemption within a year of the transfer.
• Only part of the value is protected: your parent’s assessed value plus an exclusion amount that resets every two years for inflation.

If the home is worth more than your parent’s assessed value plus that amount, the difference gets added.

An example: your mom’s assessed value is $300,000 and the home is worth $1,500,000 when it passes to you in 2026. The cap is $300,000 plus $1,044,586, or $1,344,586. The home is worth $155,414 more than that, so your new assessed value is $455,414. In Fremont that’s about $5,349 a year instead of $17,619. Move in, and you keep about $12,270 a year. Rent it out, and you pay the full $17,619.

Grandchildren can use the same rule only when their parent who was the grandparents’ child has passed away.

What Prop 19 doesn’t do

• It doesn’t cover rentals or second homes. Both the moving rule and the inheriting rule are about main homes. Family farms have their own inheritance rule.
• It doesn’t carry over fixed charges. Mello-Roos, parcel taxes and other special assessments belong to the new property.
• It doesn’t lower your tax rate. You pay the rate where the new home is. Here are the rates for every Alameda County city.
• It doesn’t happen on its own. You have to file a claim.

Forms and deadlines

In Alameda County the forms are on the Assessor’s website, and claims go to the Alameda County Assessor’s Office, 1221 Oak Street, Room 145, Oakland, CA 94612.

Is Prop 19 changing?

Not this year. Nothing on the November 3, 2026 ballot changes it. A proposed initiative to undo the inheritance changes was cleared to collect signatures in 2025, but it didn’t make this ballot. The parent to child exclusion amount resets next on February 16, 2027, and I’ll update the calculator when the new number is out.

Questions people ask

I’m a REALTOR®, not a tax advisor or attorney. This page and the calculator are general information and estimates, not tax or legal advice. The county assessor decides your assessed value. Confirm your situation with the assessor, a CPA or an estate attorney before you act on it.