Stepped-Up Basis Explained With a Real Example

TL;DR: Stepped-up basis sounds abstract until you see it with real numbers. Parent bought for $50K, worth $400K at death, sold for $410K — taxable gain is $10K, not $360K.

_Last reviewed: July 2026 · 4 min read_

If you've heard of "stepped-up basis" but the mechanics sound abstract, the honest answer is: watch it work with real numbers and the whole concept clicks in about 60 seconds. A parent who bought a house for $50,000 in the 1970s dies today with the home worth $400,000. The heir sells for $410,000. The taxable gain is $10,000, not $360,000. That's the entire idea.

Okoniq Property Hub stores the appraisal, deed, and sale documents together so the arithmetic is a lookup, not a research project. Here's the walk-through.

The starting numbers

• Parent bought the home in 1976 for $50,000
• The parent died in 2026 with the home appraised at $400,000 on the date of death
• The heir sells the home 8 months later for $410,000
• Selling costs (agent commission, closing): $28,000

Step 1 — The heir's basis

Without stepped-up basis (if this were a normal purchase), basis would be what the parent paid: $50,000. With stepped-up basis, basis "steps up" to fair market value at date of death: $400,000.

That $350,000 jump doesn't cost anyone tax — it's the government's decision to reset the clock at the transfer between generations. The parent's decades of appreciation are excluded from income tax entirely (it may have been in the estate for estate-tax purposes, but the estate exemption is currently over $13 million per person, so almost never applies).

Step 2 — The gain calculation

Gain = Sale price — Selling costs — Basis

Gain = $410,000 — $28,000 — $400,000 = -$18,000

Wait, that's a loss of $18,000. Under IRS rules:

• If the inherited property was your residence or held for personal use, the loss is not deductible.
• If held as investment or rental, the loss may be deductible as a capital loss.

For most inherited-house sales, the practical effect is simply "no tax owed" — the loss doesn't help but nothing is due.

Step 3 — What if the sale is higher?

Change the scenario: sale price is $460,000 instead of $410,000.

• Gain = $460,000 — $28,000 — $400,000 = $32,000
• This gain is long-term capital gain (inherited property is automatically long-term)
• Federal tax at 15% (typical middle-income rate) = $4,800 federal
• Plus state tax on capital gains in most states

Same house, same starting inputs — a $50,000 higher sale price triggers $4,800 in federal tax. That's roughly 9.6% marginal tax on the incremental gain — a much lower rate than ordinary income.

Step 4 — What if the parent's purchase price mattered?

If it did (imagine no step-up), the gain would be:

$460,000 — $28,000 — $50,000 = $382,000

At 15% federal long-term capital gains + state tax + possibly Net Investment Income Tax → real tax bill in the $70,000+ range.

Stepped-up basis saved the heir roughly $65,000 in federal tax in this scenario. That's why it's one of the tax code's most consequential provisions.

How to make sure basis is defensible

The stepped-up basis is only as good as your documentation of the fair market value on date of death. Best-in-class:

• Written appraisal by a certified real estate appraiser dated near the date of death
• Backup: comparative market analysis (CMA) from a licensed Realtor
• Property tax assessment from that period (usually lower — not preferred as sole documentation)
• Comparable sales research at the time, preserved with dates

If an appraisal wasn't done at death, a retrospective appraisal — done later, valuing the property as of the date of death — is still valid and accepted by the IRS in practice.

Keep basis calculations documented clearly

The paperwork trail is easy to lose in the year after a death. Okoniq Property Hub stores the appraisal, deed transfer, executor documents, and post-inheritance receipts so a future sale is a clean calculation, not archaeology. Related: how to calculate cost basis on an inherited house, I inherited a house — do I owe taxes if I sell?, and the Taxes & Accounting hub. The IRS's Publication 559 has more worked examples.

Frequently asked questions

What if only half the house was inherited (spouse still living)?

In non-community-property states, only the deceased spouse's half gets stepped-up. The survivor's half retains original basis. In community property states (CA, TX, AZ, WA, NV, ID, LA, NM, WI), both halves typically step up — a "double step-up" that's often much better.

Do I lose the step-up if I hold the property for years?

No. The step-up locks in at date of death. If you hold and the property appreciates further, only that post-inheritance appreciation is taxable when you sell — not the pre-inheritance appreciation.

What if I move into the inherited house?

If you live there as your primary residence for 2 of the next 5 years, you can also claim the Section 121 $250K/$500K exclusion on top of the stepped-up basis — potentially wiping out gain entirely. See Section 121 exclusion for married filing jointly.

Not tax advice. Inherited-property tax scenarios interact with state law, estate structure, and depreciation history — confirm with a licensed CPA. Okoniq Property Hub keeps the paperwork organized. Get started free.

FAQ

How much does a retrospective appraisal cost if we didn't get one at the time of death?

A retrospective appraisal typically costs $400–$700 for a single-family home, similar to a standard appraisal, and the IRS accepts it as valid documentation of date-of-death value as long as the appraiser clearly states the effective date and uses comparable sales from that period.

Can I use Zillow or Redfin estimates to prove stepped-up basis to the IRS?

No — online estimates like Zestimates are not considered reliable evidence by the IRS and will be rejected in an audit; you need a written appraisal from a certified appraiser, a comparative market analysis from a licensed Realtor, or documented comparable sales research with dates.

If my parent added me to the deed before death, do I still get stepped-up basis?

No — if you were added as a joint owner with rights of survivorship before death, your basis is a blend of the original cost (for your gifted share) and stepped-up value (for the inherited share), which usually results in a much higher tax bill than inheriting outright at death.

Does stepped-up basis apply to rental properties or only primary residences?

Stepped-up basis applies to all inherited real estate — rental properties, vacation homes, and raw land all step up to fair market value at death, though any depreciation recapture claimed by the deceased is wiped out by the step-up.