What is the step-up in basis?

Under IRC §1014, an inherited asset's cost basis resets to its fair market value on the date of the original owner's death. All the unrealized appreciation accumulated during the owner's lifetime disappears for capital-gains tax purposes — an heir who sells immediately after inheriting owes essentially zero capital-gains tax on that pre-death appreciation.

When does holding to death beat selling now?

When the position has substantial unrealized gains, the owner doesn't need to liquidate for living expenses, and there's a meaningful number of years of expected remaining growth. The advantage mathematically equals the capital-gains tax that would have been paid today, compounded at the same growth rate over the holding period.

Does the step-up apply to all inherited assets?

It applies to most capital assets — stocks, real estate, business interests. It generally does not apply to tax-deferred retirement accounts (traditional IRAs, 401(k)s), which pass to heirs with their existing tax treatment intact, or to assets already held in certain irrevocable trust structures.

Does gifted property get the same step-up as inherited property?

No. A recipient of a lifetime gift inherits the donor's original (carryover) cost basis, not a stepped-up one. The step-up specifically requires the transfer to happen at death, which is one reason estate planners often prefer holding appreciated assets for inheritance rather than gifting them during life.

Holding a $1M Stock Position to Death Instead of Selling Now Can Leave Heirs $290K Richer

Under IRC §1014, a fundamental (and often underused) rule of the tax code resets an inherited asset’s cost basis to its fair market value on the date of the original owner’s death. We ran the actual hold-vs-sell math on a representative position to see how much that rule is really worth.

The scenario, run both ways

A $1,000,000 stock position with a $200,000 cost basis (an $800,000 unrealized gain), held for 15 more years at an assumed 6% annual growth, 15% federal long-term capital-gains rate:

Path	What happens	Value in 15 years
Sell now, reinvest net	Pay $120,000 LTCG tax today, invest the remaining $880,000	Compounds at 6% from a lower starting base
Hold to death	No sale, no tax event; heir receives stepped-up basis	Compounds at 6% from the full $1,000,000
Step-up advantage		≈ $290,000

The advantage isn’t arbitrary — it works out to exactly the capital-gains tax that would have been paid today ($120,000), compounded forward at the same growth rate over the holding period. Both paths grow at the identical rate; the sell-now path simply starts with less principal because of the immediate tax bill.

Why this is the single biggest tax break tied to a single provision

For assets bought decades ago and held through major appreciation — a stock position that’s 10x’d, a family home that’s 5x’d since purchase — the step-up can erase hundreds of thousands of dollars of what would otherwise be phantom tax. “Phantom” because the gain is entirely on paper for the original owner; nobody actually pockets the appreciation in cash until a sale happens, and if that sale never happens during the owner’s lifetime, the tax on it simply never comes due.

The planning move this implies

If you’re elderly, sitting on highly appreciated assets, and have other resources to live on, holding to death usually beats selling now and reinvesting — not because holding is inherently better, but because the tax cost of selling now is a real, quantifiable drag that compounds against you for as long as you hold the replacement investment. The math favors holding more the longer the remaining time horizon and the larger the embedded gain.

Where this calculation doesn’t apply

You need the money. The step-up only matters for assets actually held until death. Any portion liquidated for living expenses during life doesn’t get the step-up — that portion is better modeled as a regular sale.
You’re decades from typical planning age. The model rewards long holding periods, but someone with 30+ years remaining carries real concentrated-position risk by holding a single appreciated asset that long. Step-up planning is mostly relevant starting around age 70, when the remaining holding period is shorter and more predictable.
State estate tax still applies. IRC §1014 is a federal capital-gains rule. A large estate can still owe state estate tax on the held position even while fully capturing the federal step-up benefit — the two aren’t the same tax.
High-MAGI taxpayers and the 3.8% NIIT. The Net Investment Income Tax adds 3.8% on top of the LTCG rate for higher earners on the sell-now path, making the step-up advantage somewhat larger than the baseline 15%/20% LTCG comparison alone would suggest.
Tax-deferred retirement accounts. Traditional IRAs and 401(k)s don’t get a basis step-up at all — they pass to heirs with their existing pre-tax treatment, an entirely different (and generally less favorable) outcome, covered by the SECURE Act’s 10-year distribution rule instead.

What to actually do

Identify which of your holdings have the largest embedded gains relative to current value — those are where step-up planning matters most.
Confirm you have other resources to cover living expenses without needing to liquidate the appreciated position.
Check whether your estate is exposed to state estate tax separately — the step-up doesn’t eliminate that liability even when it eliminates the federal capital-gains one.
If a position needs partial liquidation for spending, sell lower-basis or already-diversified holdings first, preserving the most appreciated positions for the step-up.
Coordinate with a financial advisor if the position represents significant concentration risk — the tax argument for holding has to be weighed against the investment risk of an undiversified estate.

Open the Step-Up Basis Calculator → and run your own position size, basis, and holding period.