Step-Up in Basis at Death

When you inherit an asset, its cost basis—the value used to calculate future capital gains tax—resets to its fair market value on the date of death. This “step-up in basis” means an heir can sell inherited stock, real estate, or other assets at no capital gains tax if they sell at or near the inherited value. The appreciation that occurred during the decedent’s lifetime vanishes from the tax calculation.

How the step-up works: a concrete example

Suppose your mother bought 100 shares of Apple stock in 2000 at $25 per share. She paid $2,500. Over 23 years, Apple rose to $150 per share. On the day she died in 2023, the stock was worth $15,000—a $12,500 unrealized gain.

Under the step-up rule, when you inherit those shares, your new cost basis is $150 per share (the value on her death date), not $25. If you sell the shares immediately at $150, you owe zero capital gains tax. The entire $12,500 gain that accumulated during her lifetime is erased for tax purposes.

This is not a deferral—it’s permanent forgiveness. The original owner never pays tax on that $12,500. Their heirs inherit the stock with a “stepped-up” basis, and unless the stock appreciates further after the inheritance, there’s no taxable event.

The step-up applies to any assets held until death: individual stocks, mutual funds, real estate, collectible art, jewelry, antiques. If a building was worth $500,000 when the owner bought it in 1980 and $2 million when they died in 2024, the heir’s basis is $2 million. The $1.5 million appreciation during the owner’s lifetime is untouched and untaxed.

Why the step-up exists: legislative intent

The step-up is a longstanding feature of U.S. tax law. Congress created it partly out of administrative simplicity—tracking basis for decades can be messy—and partly out of a political judgment that gains should be taxed when they’re realized (converted to cash), not when someone dies. Death itself is not treated as a realization event.

There’s also a fairness argument: if the original owner didn’t sell and didn’t trigger tax, should their heirs be responsible for back-taxes on appreciation they never benefited from? The step-up says no. The tax system essentially grants a one-time forgiveness at the moment of death.

For wealthy dynasties, the step-up is extremely valuable. A family business or apartment building that’s held for generations and passed down tax-free represents enormous transferred wealth that never encounters the capital gains tax. This is why the step-up is politically contentious and why policymakers periodically propose eliminating or limiting it.

Limitations and complications

The step-up applies broadly, but it’s not universal. Several important assets do NOT receive a stepped-up basis:

• IRAs and retirement plans: A traditional IRA steps up in basis, but the distributions are still taxed as ordinary income. A Roth IRA provides qualified distributions tax-free to heirs. This is genuinely better than a step-up, but it’s a separate rule.
• 401(k) plans: Inherited 401(k)s are taxed as ordinary income to the beneficiary, no step-up.
• Appreciated interests in partnerships or S-corporations: The step-up applies to the asset, but carryover rules can complicate the calculation.
• Foreign real estate: The U.S. step-up applies to worldwide assets of U.S. citizens, but some other countries don’t recognize it.

The step-up also has a timing issue. The fair market value on the date of death is what matters. If you inherit stock on January 15 and the stock crashes on January 16, you’re locked in at the higher value. There’s a six-month alternative valuation date election available for large estates—the decedent’s executor can choose to value assets six months after death instead—but this is only useful if the estate shrinks over that period, and it’s complex to administer.

Holding periods and tax rates

An important detail: the step-up only eliminates the gain that occurred before death. If you inherit stock and it appreciates further before you sell, you owe capital gains tax on the new gain.

More favorably, the holding period is treated as long-term for tax purposes. If you inherit 100 shares and sell them six months later, the gains are taxed at the long-term capital gains rate (15% or 20%, depending on income), not the short-term rate (ordinary income, up to 37%). This is generous: most assets must be held for over a year to qualify for long-term treatment.

High-net-worth planning and the step-up

For high-net-worth clients, the step-up is a core planning pillar. Advisors often recommend holding highly appreciated assets until death rather than selling them—the client avoids a large tax bill, and the heirs inherit the stepped-up basis. This strategy works for people confident they won’t need the cash before death, or for whom the estate is so large that a capital gains tax bill would be manageable.

For other clients, the step-up influences charitable giving strategy. Donating appreciated securities to charity eliminates capital gains tax and generates a charitable deduction, often outperforming a bequest in a will that would just use the step-up.

The step-up also interacts with estate tax planning. If an estate is large enough to owe federal estate tax (the threshold is $13.61 million per person in 2024, but it sunsets to roughly $7 million in 2026), the step-up doesn’t reduce the estate tax—that’s levied on the fair market value at death regardless. But the step-up does reduce the income tax burden for heirs who need to sell assets to pay the estate tax bill.

Proposed changes and uncertainty

The step-up is politically vulnerable. Policymakers and tax economists argue that it creates an enormous loophole—trillions in unrealized gains escape taxation indefinitely if held and bequeathed. Various administrations have proposed “mark-to-market” rules that would treat death as a realization event, taxing the appreciated value as if the decedent had sold everything on their death date.

Such proposals have never passed, partly because they’re administratively complex and politically unpopular with middle-class families who own homes. But uncertainty persists, especially for very large estates. A high-net-worth individual cannot assume the step-up will survive unchanged into the next decade.

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