One of the most valuable provisions in the tax code is also one of the least understood by the families it benefits: when a person dies, most of the assets they leave behind are handed to heirs at their current market value, not the price the deceased once paid. That reset, known as a stepped-up basis, can erase the capital-gains tax on decades of appreciation in a house, a brokerage account, or a piece of land. For a retiree deciding whether to sell an asset now or hold it for the next generation, the rule quietly tilts the math toward waiting.
How the step-up in basis works
Capital-gains tax is charged on the difference between what an owner paid for an asset — the cost basis — and what it sells for. A stock bought for $20,000 and sold for $120,000 produces a $100,000 taxable gain. But when the owner dies holding that stock, the heir’s basis is reset to the value on the date of death, a rule the IRS lays out in Tax Topic 703 on the basis of assets. If the heir then sells near that stepped-up figure, the gain — and the tax on it — can shrink to almost nothing.
The reset applies to the fair market value on the date of death, though an estate may instead elect an alternate valuation date six months later when that lowers the taxable estate. IRS Publication 551 spells out how that value becomes the heir’s new basis for figuring gain or loss on a later sale. The practical effect is that a lifetime of growth an owner never cashed out, and therefore never paid tax on, passes to the next generation with that embedded gain wiped clean.
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What resets and what does not
The step-up covers the assets most families think of as their estate: a primary home, rental property, land, and taxable brokerage holdings such as stocks, bonds, and mutual funds. These are the assets where an owner may have sat on large unrealized gains for years precisely because selling would have triggered a bill. At death, that reason to hold vanishes for the heir, who inherits at the higher value and can sell with little or no capital-gains tax to settle.
Retirement accounts are the major exception, and the difference is easy to miss. A traditional IRA or 401(k) does not receive a step-up; the money in it was never taxed, so a beneficiary who inherits it pays ordinary income tax on withdrawals, generally on a schedule that empties the account within ten years. IRS Publication 559, written for survivors and executors, treats inherited retirement money and inherited property very differently, and a family that assumes both get the same clean reset can be caught off guard by a large tax bill on the account.
Married couples get an added wrinkle. In most states, only the deceased spouse’s share of a jointly owned asset steps up, while the survivor keeps their original basis on the other half. In community-property states, both halves can reset at the first spouse’s death, a double step-up that can matter enormously for a couple holding a long-appreciated home or portfolio. Which rule applies depends on state law and how the asset is titled, not on the size of the estate.
The planning decision it creates
The rule reframes a common instinct to give assets away during life. Handing a grown child appreciated stock or a house while still alive transfers the giver’s original basis along with it — a carryover, not a step-up — so the child inherits the built-in gain and the tax that comes with selling. Passing the same asset at death instead delivers it with a reset basis, often a far better outcome for the recipient even though it feels less generous in the moment.
That trade-off runs against another goal families hold, which is simplifying an estate before death. Selling a highly appreciated asset late in life to tidy up finances can hand the IRS a gain that would have disappeared had the owner held on a little longer. The step-up rewards patience with concentrated, low-basis positions, which is the opposite of the diversify-and-simplify advice that otherwise makes sense.
The reset can also cut the other way. If an asset has fallen below its purchase price, death steps the basis down to the lower value, locking in a loss the heir cannot claim. An owner sitting on a depreciated holding may be better served selling it during life to harvest the loss for their own return, rather than passing it along at the reduced basis.
None of this eliminates the paperwork that makes the benefit real. Heirs still need a defensible value as of the date of death — an appraisal for real estate, brokerage statements for securities — because that figure is the number the IRS will measure any later sale against. Without it, a family can lose the step-up in practice simply by being unable to prove what the asset was worth when it was inherited.
For retirees, the takeaway is less a to-do list than a shift in framing. The assets carrying the largest unrealized gains are often the ones most worth holding to the end, while the accounts that feel like the cleanest inheritance — the traditional IRA, the old 401(k) — are the ones that arrive with a tax attached. Knowing which is which turns the step-up from a footnote in the tax code into a decision that can move real money to the next generation.
This article was produced with AI assistance and reviewed against primary sources by The Money Overview editorial team.
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