Big Mistake: A 72-Year-Old Couple Will Hold $600,000 of Stock in a Joint Account. When He Dies, Only Half Will Get the Tax-Free Step-Up. Across the State Line in Texas, All of It Would

Picture a married couple, both 72, living in southern Oklahoma, a short drive from the Red River. Over four decades they built a $600,000 brokerage account, titled jointly with right of survivorship, mostly in stock bought long ago for about $150,000. When the husband dies, his wife inherits the whole account, along with a tax bill quietly attached to her own half.

This setup is extremely common. Joint ownership is the default at most brokerages, and few couples ask how it interacts with the tax code at death.

Why Texas Couples Get Twice the Tax Relief

When someone dies, inherited assets generally receive a new cost basis equal to fair market value on the date of death. For jointly owned property, the IRS treats each spouse as owning one-half. Only the deceased spouse’s half resets. “The basis in your interest will remain the same,” the IRS explains.

Community property states work differently. In Arizona, California, Idaho, Louisiana, Nevada, New Mexico, Texas, Washington, and Wisconsin, when either spouse dies, “the total value of the community property, even the part belonging to the surviving spouse, generally becomes the basis of the entire property.” Planners call this the double step-up.

Farm families face the same gap at a larger scale. Agricultural law professor Roger McEowen shows it with Kansas farmland bought for $500,000 and worth $3,000,000 at the first death: joint tenancy leaves the survivor facing a $1,250,000 taxable gain on a sale, while community property treatment leaves $0.

Running the Numbers on a $600,000 Account

For our Oklahoma widow, her new basis is about $375,000: half the original cost plus half the date-of-death value. Selling everything would trigger roughly $225,000 of gain. At a 15% federal rate, that is about $33,750. If the 3.8% net investment income tax also applies (it starts at $200,000 of income for single filers), the bill rises to roughly $42,300. In Texas, the same widow would owe close to nothing.

Widowhood makes this worse. After the year of death she files as a single taxpayer, with narrower brackets that push more of that gain into higher rates.

One Question Decides Whether This Costs You

The real tension is whether the survivor will need to sell. If she holds every share until her own death, her half steps up then, and the heirs never feel the gap. The cost lands only on lifetime sales: reducing a concentrated position, funding assisted living, or moving into simpler investments. A 72-year-old widow with many years ahead will almost certainly sell something, which is why this deserves attention now.

Two Paths Worth Taking Seriously

Path 1: A community property trust. A growing group of states lets married couples opt into community property through a special trust. Alaska allows it by agreement, Florida has a Community Property Trust Act, and Kansas joined the group effective July 1, 2026. Tennessee, Kentucky, and South Dakota also offer versions, according to estate planning practitioners. History supplies a caution here: in Commissioner v. Harmon, the Supreme Court refused to honor Oklahoma’s old elective community property law for federal tax purposes, and legal scholars still debate how far opt-in systems qualify for the full step-up. The trusts also carry tradeoffs, including a step-down on assets that have lost value and the loss of certain creditor protections, as McEowen notes.

Path 2: Shrink the gain while both spouses are alive. Realize gains in years when joint brackets keep the rate low, donate the lowest-basis shares for any charitable giving you already plan, and spend from high-basis lots first. This chips away at the problem without legal fees.

For this couple, Path 1 makes the most sense if they can access a statute through a qualifying trustee. A one-time legal fee is small next to a potential five-figure tax bill. If no workable statute is available, Path 2 is the default, and it should start this year rather than after a diagnosis. Either way, titling and beneficiary paperwork decides more of the outcome than most couples realize, which is the whole reason we put together a free estate checklist covering wills, trusts, and how accounts are held.

What to Do Before the First Death

1. Pull the cost basis report on your joint account. If the embedded gain on the surviving spouse’s half runs into six figures, that is the specific trigger for paying an estate attorney who knows community property trusts. Ask directly whether your state, or a state where you can name a trustee, offers one.
2. Skip the deathbed transfer. Some couples shift appreciated stock into the sicker spouse’s name, hoping it comes back with a full step-up. The IRS blocks this: if you give appreciated property to a spouse who dies within 1 year, your basis stays “the same as the decedent’s adjusted basis in the property immediately before their death.”

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