Double Step-Up in Basis for Community Property at Death

In community property states, both halves of jointly owned assets receive a double step-up in basis when one spouse dies—a rare and valuable tax mechanism that resets the entire property value to current market price for tax purposes, rather than only the deceased spouse’s half.

Why Only One Half Steps Up in Common-Law States

In the majority of U.S. states—those following common-law property rules—married couples hold assets as either joint tenants with rights of survivorship or as tenants in common. When one spouse dies, only the deceased spouse’s half of the property receives a step-up in basis to its fair market value at the date of death.

The surviving spouse’s half retains its original cost basis. If a couple bought stock for $100,000 and it grew to $500,000, and one spouse dies when the stock is worth $500,000, the deceased’s half ($250,000 value) steps up to $250,000 basis. But the survivor’s half still carries the original $50,000 basis applied to that portion. The survivor now owns an asset worth $500,000 with a combined basis of only $300,000—embedding a $200,000 capital gain that will trigger tax when sold.

The Community Property Advantage

Community property states operate under a fundamentally different ownership model. In these states, assets acquired during marriage are presumed to be owned equally by both spouses, regardless of which spouse earned the income or took title. This shared ownership applies automatically unless spouses take deliberate steps to opt out.

The critical tax consequence: when one spouse dies in a community property state, both halves of the community property asset step up in basis. Using the $100,000-to-$500,000 stock example above, the entire $500,000 value becomes the new basis for the surviving spouse. There is no embedded capital gain. If the survivor sells immediately, there is no tax. The double step-up is often called a “one-free-step-up” for the living spouse.

This treatment applies regardless of which spouse earned the money, managed the investment, or held legal title. The moment one spouse dies, the IRS values the property at that moment in time, and both halves receive new basis at that stepped-up value.

How This Shapes Estate and Wealth Transfer Strategy

The double step-up can represent hundreds of thousands or millions of dollars in untaxed gains, depending on the size of the estate and the appreciation of community property assets. It reduces the capital gains tax liability faced by the surviving spouse and creates flexibility for managing the estate.

Practitioners often recommend that couples in community property states hold significant appreciated assets (equities, real estate, business interests) in community property form. Trusts can be structured to maintain or preserve community property status, and some couples make deliberate elections to treat separate property as community property in order to capture the step-up.

The benefit is most pronounced for high-net-worth households. A married couple in California who accumulated $5 million in appreciated real estate and stocks over decades can, through the death of one spouse, eliminate the entire embedded capital gains tax on those assets for the survivor. Compare that to a couple in New York with identical assets: the surviving spouse carries forward billions of dollars in deferred tax liability.

Why Common-Law States Don’t Offer This

The root difference lies in ownership structure. In common-law jurisdictions, each spouse is treated as owning a distinct, separate half of jointly titled property. That separateness is why only the deceased spouse’s half qualifies for step-up treatment—only their interest in the property “passes through the estate.”

The survivor’s half never passed through the estate; it passed by operation of law (survivorship). Because the survivor already owned it and did not acquire it at death, the tax code sees no reason to reset its basis. This logic is consistent but harsh for the survivor’s tax position.

Community property states reject this separateness fiction. Each spouse is seen as owning the whole asset together from the outset. At death, the entire asset is revalued, and the survivor’s newly acquired full ownership (replacing the deceased’s half) is valued at the step-up price.

Community Property Elections and Portability

Some community property states allow spouses to elect that separate property be treated as community property. This is most common in California and Texas. A spouse can move separate property into community property status through written agreement or by placing it in a community property trust. The election itself triggers no gain; the benefit arrives at death, when the step-up applies.

Couples in community property states often combine the double step-up strategy with federal estate tax planning tools. The portability of a deceased spouse’s unused estate tax exemption (available since 2011) further simplifies planning for large estates. The double step-up is independent of portability; it applies to basis regardless of estate tax exemption status.

Portability and Basis Step-Up Are Separate Benefits

A common misconception: the double step-up and estate tax portability are the same thing. They are not. Portability lets the surviving spouse use the deceased’s unused estate tax exemption to shelter additional assets from federal estate tax. The double step-up resets the income tax basis of appreciated property.

Both can apply to the same estate, but they address different taxes. The double step-up benefits income tax. Portability benefits estate tax. In low-appreciation or low-value estates, the step-up may be more valuable. In high-value estates, portability is often the larger benefit.

The Broader Tax Comparison

The double step-up in community property states is often cited as one of the last major tax advantages for married households. Individual tax brackets, the standard deduction, and capital gains tax rates apply equally in all states. But the double step-up is unique to nine jurisdictions.

For high-net-worth couples—particularly those building significant real estate, publicly traded stock, or business equity—the difference in lifetime and after-death tax liability between a community property state and a common-law state can easily reach six or seven figures. Some couples and their advisors have even relocated to capture this benefit, though the decision to change residence involves many other legal, personal, and logistical considerations.

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