Community Property vs. Separate Property Step-Up in California

Community Property vs. Separate Property Step-Up in California

Community property gets a full basis step-up when one spouse dies; separate property only gets a half step-up. That single distinction, under IRC section 1014(b)(6), can be worth six figures on an ordinary California house. Two identical properties, same value, same date of death, same trustee selling both: one sale owes no capital gains tax, the other owes tax on half the appreciation. The only difference is how the property was actually held.

This is the single most consequential characterization question in California trust administration, and it’s one a lot of trustees never think to ask because the house has “always just been theirs.”

The baseline rule, and the extra step California gets

Federal tax law treats community property and separate property differently at death, and California trustees run into this constantly because California is one of the handful of community property states. Under IRC section 1014(a), any capital asset gets its basis reset to fair market value as of the date of death. That’s the baseline rule everywhere in the country, community property state or not.

But under IRC section 1014(b)(6), community property gets something extra. When one spouse dies, both halves of the community property step up to fair market value, not just the half that belonged to the person who died. The surviving spouse’s own half, the half they already owned and never inherited anything, also resets. That’s unusual. In most of the country, a surviving joint owner only gets a step-up on the portion they inherited; their own pre-existing share keeps its old basis. California residents effectively get a second bite at the step-up that most states don’t offer.

Separate property doesn’t get that extra step. If an asset was separate property, only the deceased owner’s share resets to fair market value. Whoever holds the other share, a surviving spouse who wasn’t a community property co-owner on that particular asset, a sibling as a joint tenant, a co-owner from a prior relationship, keeps their original basis on their portion. No death, no step-up, no matter how long ago the original purchase happened.

A concrete example, worked through both ways

Say a married couple bought a house in 1990 for $150,000, held it as community property throughout the marriage, and one spouse dies decades later when the house is worth $1,150,000.

As community property, the entire basis resets to $1,150,000. If the surviving spouse or the trust sells the house shortly after for $1,150,000, there’s no capital gain to tax. All $1,000,000 of appreciation is gone, for tax purposes, in an instant. That’s the clean outcome, and it’s exactly what most families assume happens with any inherited house.

Now change one fact. The same house was actually the deceased spouse’s separate property, inherited from a parent before the marriage and never transmuted to community property. Only that spouse’s basis resets. If the couple held it as tenants in common with equal shares, half the basis steps up to $575,000 (half of the $1,150,000 fair market value), and the other half keeps its original basis, likely a small fraction of that, since it reflects 1990-era or earlier value on the surviving owner’s half. Sell the house for $1,150,000, and there’s meaningful capital gain on that surviving owner’s original half, taxed at ordinary capital gains rates that, combined with California’s state income tax (which doesn’t distinguish capital gains from ordinary income), can easily run 30 percent or more of the gain.

Same house. Same sale price. Same date of death. A tax difference that can run into six figures, based entirely on how a piece of paper decades ago characterized the asset.

Why characterization isn’t always obvious

Under California Family Code section 760, property acquired during marriage is presumed community property. That presumption is a strong starting point, but it gets rebutted constantly in real trust administrations. Under Family Code section 770, an inheritance or gift received during the marriage is separate property by default, even if the couple was married the entire time they owned it and even if both spouses’ names ended up on the title later. Property owned before the marriage stays separate unless the couple affirmatively transmuted it into community property.

Then there’s the funding question, which is where most of the real fights happen. A house bought with one spouse’s separate inheritance money but titled in both names can raise a completely different set of presumptions than one bought with community earnings but titled in only one spouse’s name. Title and funding source don’t always match, and when they don’t, California law has a hierarchy of presumptions that decides which one wins. None of this is something a trustee should work out from memory or from what a beneficiary remembers about “how Mom and Dad always talked about the house.” It requires looking at when the asset was acquired, whose funds paid for it, how title was held at each point in time, and whether a transmutation happened along the way.

Transmutation: how separate property becomes community property (or vice versa)

Since 1985, California has required a written transmutation agreement to change an asset’s character between spouses. It has to expressly state that the character of the property is changing; simply adding a spouse’s name to a deed, without more, is generally not enough to convert separate property into community property for these purposes, though it can still matter for other legal questions. If your parents’ estate planning documents, deeds, or trust schedules include language about transmutation, that paperwork often decides the whole basis question, and it’s worth finding before anyone assumes an answer either way. I cover the mechanics of how transmutation agreements work and what makes one enforceable in transmutation agreements in trust administration.

Why this matters more for real property than people expect

Cash and most securities held in a joint account don’t usually carry the same drama, because ownership tends to be documented clearly and gains, while real, are often modest relative to the size of a typical account. Real property is where this issue causes real financial damage, because California real estate has often appreciated enormously over decades of ownership, and because a mischaracterized property can turn what should have been a tax-free sale into a five- or six-figure tax bill nobody budgeted for. If a piece of real property in the trust also passed through joint accounts or was commingled with community funds over the years, the characterization question gets even harder. I walk through how commingling affects that analysis in commingled assets in trust administration.

Get the appraisal, then get the characterization right

Basis always starts with a date-of-death value, whether the asset ends up with a full or half step-up. Without a proper appraisal there’s no fixed number to step up to, and no defensible starting point if the IRS ever questions the sale. I explain why that valuation has to happen early, and how it’s actually done, in the date-of-death appraisal.

The honest caveat

Characterization is not always a clean answer. Some assets genuinely are what California family law calls “mixed character,” part community and part separate, because they were purchased with a blend of funds or improved with community money over the years by a couple who never formally addressed it. In those cases the step-up isn’t a simple full-or-half question; it can require an apportionment calculation that depends on records some families no longer have. Don’t assume you can eyeball this from an old deed and a family memory. Get the actual documents pulled and reviewed before a trustee reports any gain to the IRS.

Talk to a real California estate attorney

If you’re a trustee sorting out whether an asset was community or separate property before a sale, I can walk through the title history, the acquisition records, and any transmutation paperwork, and get the characterization right before the tax return gets filed, not after.

Talk to Eric Ridley is a free 60-minute consultation by phone or Zoom, anywhere in California. Or call (805) 244-5291. You’ll leave knowing where you stand, whether or not you hire me.

Related reading: Stepped-up basis in a California trust, explained · Characterizing assets after death in California · Surviving spouse rights in trust administration

Frequently asked questions

Does community property get a bigger step-up in basis than separate property in California?

Yes. Under IRC section 1014(b)(6), when one spouse dies, both halves of community property step up to fair market value, not just the deceased spouse’s half. Separate property only steps up the deceased owner’s share; the surviving co-owner keeps their original, lower basis on the rest.

How do I know if an asset is community property or separate property in California?

Under Family Code section 760, property acquired during marriage is presumed community property. Under Family Code section 770, an inheritance or gift received during marriage is separate property by default. Property owned before marriage stays separate unless the couple transmuted it. Characterization depends on acquisition date, funding source, and title.

What happens if a trustee guesses wrong about characterization?

Treating separate property as community property overstates the step-up and understates gain on a later sale, creating tax exposure for the trust and beneficiaries. Treating community property as separate property understates the step-up, which can cause the trust to overpay capital gains tax that was never actually owed.

Can separate property become community property in California?

Yes, through a transmutation, a legal change in how an asset is characterized between spouses. Since 1985, California requires a written transmutation agreement that expressly states the change in ownership; informal understandings or simply adding a spouse’s name to title are generally not enough on their own.

Does the full step-up apply to real estate held in joint tenancy between spouses?

Sometimes, but it isn’t automatic. Property titled in joint tenancy between spouses can still be community property in substance if it was acquired with community funds during marriage. What matters for the full 1014(b)(6) step-up is the underlying community property character, not just how title reads on the deed.

This is general information about California law, not legal advice for your situation.