If you inherited a home in California before April 1, 2021, the rules that governed your property tax basis no longer apply to anything you do with that home after that date. Most people don't fully understand the size of the cliff they're standing on.
The old rule (pre-Prop 19)
Before April 2021, when a parent left a home to a child in California, the child could keep the parent's original property-tax assessed value — no matter what the home was actually worth, no matter whether they lived in it, no matter whether they rented it out.
A $400,000 assessed value on a home now worth $3 million was a transferable inheritance. Children kept paying tax on $400,000 — forever.
The new rule (post-Prop 19)
Prop 19 changed three things at once:
- The transfer of tax basis only applies if the child moves in as their primary residence.
- There's a $1 million exclusion above the parent's assessed value, beyond which the home is partially reassessed.
- The child has one year from the date of inheritance to move in and file for the homeowners' exemption.
If you inherited the home before April 1, 2021, the old rules still cover what you have today — but they do not cover what your kids will inherit from you.
What this means for the typical scenario
A homeowner in their late 60s, with a home they inherited from their parents 15 years ago at $400K assessed value, sitting on a property worth $2.5M today, paying ~$5,200 a year in property tax. The current resident has two adult children.
Three options, three very different tax outcomes:
| Choice | What happens | Annual property tax |
|---|---|---|
| Keep the home, leave it to kids | Kids must move in within 12 months OR home gets reassessed to market value | $400K basis today → ~$30,000/year reassessed for the kids |
| Sell now (before age 55+ rules apply) | Capital gains tax on gain above the $250K/$500K exclusion | Loses the basis entirely |
| Sell + buy a replacement home using Prop 19 portability | Transfer basis to new home (one-time, age 55+) | Basis ports — still ~$5,200/year on new home |
The right answer depends on whether the kids actually want the home, and whether the homeowner is over 55. But the math almost always points toward selling-and-porting before the homeowner ages further, not after.
The thing nobody tells you
Prop 19's age-55+ portability rule is a one-time use per lifetime per spouse. Some couples can technically use it twice (once for each spouse) but that requires structure and timing that needs to be set up before you sell. If you sell first and ask later, you've lost the second use.
What to do this month
- Run our Prop 19 calculator — gives you a personalized look at the inherited-home vs. sell-and-port scenarios.
- Run our Sell Before Prop 19 calculator — specifically for homeowners considering the move-and-port path.
- Have one short conversation with a CA-licensed agent who has actually executed Prop 19 portability transactions. The mechanics are formal and one missed step costs you the basis permanently.
You don't have to decide today. But the cost of waiting another five years — and burning the chance to use portability — is something every California homeowner over 55 should understand before they decide whether to keep doing nothing.
Eric Plotkin is a founding agent at Newmarket Edge and a 12-year California real estate veteran. This article is informational and does not constitute legal or tax advice. Consult your CPA and an attorney for guidance specific to your situation.